'01.66 September. 1997 No. 3

Nematological Abstracts

The past, qresent and future of plant nematology m International Agricultural

Research Centres 1791

Shashi B. S h a m a t , Nigel S. Pricea a n d J o h n Bridge' 'International Crops Research Institute for the Semi-Arid Tropics

(ICRISAT) Asia Centre, Patanhem, Andhra Pradesh 502 324, India. 'International Institute of Parasitology, 395A Hatfield Road,

St. Albans, Herts AL4 OXU, UK

C O N T E N T S

1, lntmduction 3.12 Cowpea 2. Plant parasitic nematodes 3.13 Soybean 3. Themajor mandate cmps of the International 3.14 Pigeonpo

Azrinilhral Research Centres and their nematode 3.15 Groundnut pansitel: 3.1 Rice 3.2 Wheat 3.3 Maize 3.4 Sorghum 3.5 Millet, 3.6 Barley 3.7 Potato 3.8 Sweet potato 3.9 Cassava 3.10 Yam 3.11 Banana and Plantain

1. INTRODUCTION

The lntematioml Agricultural Research Centres (IARCs) mrutitute an W l i o n of 16 reear& innti- cwrdinaqd bv the Coruultative Gmun on International Aericultural &arch (CGMI ~ h r esmb~hmmr of ?he C G ? V S ~ P ~ m 1971 grew largely out of rho eari~er successes or tne Ford and Rockrhller F o d o o n funced resraxh n nce wheat and maue, succosrs that c a r e !o ~e termed the ' C m n Revolution" The two h t l t u t a most ~nvolved m this work. t k I n m n a w b L a h n n r t e r m R D m d t n e C m m , lntcmaaorul de Mnoramrcnro de \lau v Tneo tClMMYn

3.16 Chickpea 3.17 Lentils 3.18 Faba Bean 3.19 Common Bean

4. Discwsion 4.1 The Institutional Neglect of Nematology 4.2 Research In Plant Nematology Reacarch

and Sustainable Agriculture 4.3 Institutional Potential of Plant

Nematology

5. References

The CGIAR itself is an informal (hence "Coruultative") grouping of natlonal governments, and public and private sector donors. W~th facilities and a secretariat supplied by the World Bank, the CGIAR receives core funding of over US $333 million a year to support the IARCs. Additionally t h IARCs mav receive com~lementaw and special pmiect hndmg d l w i v from donoA n e CC~AR vr&s l a riud~on. a5 stared In the recent "Lucerne Declararron and Action P.an" (CCIAR. 19951 aa bang "to contribute. through 11s research. to oromotlne sustakable agrlcuiture for f d recurtly In rAe develo~lng countnn"-0f the I6 IARCa. 8 are esyentwliy :roe-basta although ClAT has a major

-with t t u & w hhlukof ?-&A&& livestock research mmponmt) with &ch imtikrte generally .--.- -.- -~ .. ... (IITA) and the Cenm I n t e m a c ~ ~ ~ de ~ ~ ~ z " r r ~ m ~ g l having rerpanslbil~ty tor specific " h n d a w ~ r o p s ' ( ~ a b k i ] . (CIA77 formed the original members of the CGIAR. They Major and well-recognised efforts in the investlgatlon tuvc~wbaa iaiml b;& d y e d InMimte llrble I( and alieviation of various biotic and abiotic comtrainta Thev LARC, &ke up bu pnnctPi mtermho~l mmjammt :o prcdvcnon of t ~ c mps. mtably p u and ducuc9, and dwhtubrommglandtk~~CbbalAgncdhua:Raesreh rhe associated programmes tor the breedmg of tmproved System" with thetr activthw f o c ~ s r d on research and varletlea of t h n r crops. form a large part of me IARCs mrmng m developmg counmw whde workmg In :lose work In addttlon. the IARCs place a srror.g emphasis on parmenhip with other "playen-. notably the Satronal the jtrengthen.ng of nalional rnearch and dwelopment Agnmltunl R-rch S p n n u (SARS) of these countries organ.sanoru In the countnn they operate in and on the ( N i 19%; CCLAR 1997 a) traning of h x orgmlranav pnonre..

mate a gmeral f e r l i h r effect chat can mcrew plant growth I h k i n . 1989). Other nernanndes mav ha\.e mu* dins and hvokrable effect, on ~ l a n l rrhvr~olo& tndr~mdent nf anv , r , ~ ", -~

mntml or porasltlc mlmn Thu :ne r r r . r c i arsesrmen: 3f p.mt paras~tr nemarules 'omuct..-? c.>mcamts" can pment cowiderable d~fhculhe in e~penmentel d a m and

3.1 Rice kce ( O y z x?t~ial u the staple food of more than hvo billion omvie. vredomnantlv tn Asia where more than 90% of the . . . .vor;d's rlce .s dmk n ard carsumea Bnage rt .?. :99C, Ci :he total rlce area, abo-' 53'0 !J ~r:lga!ed 31'. :, rainfed .ow.and 13% IS -p.and an2 3'0 u aeepwarer K+ish, 198.L

:\orldw:de, nce yeld :&e :-e to p:ur paras.nc nemaloda are ostlma:ea a! lo0. Sarrc: k Frecm.an li5' Maor nematode pe ts of nce are Apivlmdwi'irs k w t , Cnconc&L onmsts, Ditvlmch~s nnuutlir, Helrmdna SDP ,'Himhwhmannielln sou.. ~o~lo in imns indi;lu. .Ilrlo~do~vnr rib.. Pnmionpldorur ,. , .,. . . spp . Prnylm:h~e spp . ana X p.!intnx !iPrr.t.r: k d g e er n.. 1993 Two spcus , A msiq: the wn.:r c p nematode and D. anglrstlrs (the uha disease nematode) are ioliar parasites. D a G due to A. k p e y ~ , whch Is a reed-borne nematode, u more severe on imeated lowlmd and d e e ~ water nce becaw a: the hlgh :e:at& h-mlc.:) found in thereslt;ations the nrrraroae ear~!v mtgrates ~nto the panicle C:op damage :a& jv A mr-4, jepencs sn me a!no~-.t 31 ~ziested seed mwn and nunbe; of nematodes per seed Extemive damage caused bv this nematode has k e n reported from Bangladesh and lndl$. The stem nematode. D, rncrtrhr8 causer, severe :a?age :n rears ~f hlgh rainia.1 and I! IS a ma.or pest In areFwarer and .owland nce 5?5remr u the great we: delta9 oi \ lcmam Indla. Bangladern and .\lyanrnar ~ l t h o u g h of xallsed occurrence, iccan cause complete yield loss.ihe ndoparas~tlc root-knot nematodes (Mrloidogyne spp.), articularly M. gram~nicoin and M. incognita are lmportant arasltes of nce. M, gmmlnrcoln is mainly found ut h u t h and .E. Asla (Bangladesh. Lam. Myanmar, PN~ppInes. Thailand, 'iemam, India), and also in the USA. Both M. incognita and d. raunnlcs cause damage to u~land nce In Africa as well as rher anar ot rhe world .it ,iioDn6 sa.arl .s :eporrea from :osta R.ra rnd Panama h'.~sc,~n~anr.rl:n spp -Ice root ematoae are vlr!uallv casno~o:~!an In lowland rlce mroduct~on systems. These migratory endoparasites of mb umduce cavttiep and channels in the cortex iHollis k :cotdonrum& 1%) They aze v m . wen adapted to comtant d m Fortuner k Memy. 1979) ana c a w greater h g c 1 low k d l t y so~u The lalon m t o d a . Pwqhrnw spp., re a h migratory endoparasites and have been reported'& Ice throughout the world. Prnryirnch~ir zmr and P indims ause significant damage to upland nce (Bridge d dl., 1990). kmatode parasitbm detmvr the mot cortex and exteMlve lamage greatly hampers mdt growth and fundlon. The cyst ~ematodes, Hetendm spp., have ken found on upland rice lthough are of mtricted dirtnbunons and thus localucd nprtance Fable 2).

h e major contributors to research In rice nematology have e n the national institutes wlthin the producing countries. bth India and Bangladesh have Natlonal R r e Research mnhrtes and a large propomon of the rerearch published on Ice nematode has emanated from the rubconhnent. Thin tan wluded surveys (e.g. Rdhman k Taylor, 1983; Prassd ci d., 983, yield loss assesmmts (e.g. Jonathan k Velayutham 9871; evaluation of chemical and nonl-henucal conhd (e.n. bhmm k Mwh 1989. bhm 1990. lunathm k Padura(m. W11. and Krrenmg and breed~ng fur newtode mutance r 8 Rahman. 1987. L h u & Chawla. 1988) W~thm Asla. the

generated research mformation (e.g. Ctbayashi sl.. 1971; Fen5 1986; Amvanuryjdnt ct 01.. 19%). Other pmmnent rice plnduong m w t n e such as hlyanmar and Vletnam also have establshed rlce nematology researrh programme 1e.g Kinh k Ngoc. 1982). The Cnited States, a malor riceexporter, has also undertaken some research in rlce nematology (e.g. kIcGawley el ai, 1981). By conwt IRRI, the longest etabllshed Lac, although lnnuenhal m diwmrnshng h d h g generated by natlonal programmes in the Asian reglon, has only recently ltseif begun to conduct nematological research. The IRRl programme starred wlth surreys and attempts at pnor~hzmg the lnnuence of nemalodes on rice product~on (eg. Pmt, 1994; Pmt ct al . 1994b;) as well as invatlgatlom of nematode-plant relationships (Prot rl ni. 19951. Of the other IARCs mandated to study rice, the West Africa Rice Development Assoclat~on OVARDA) has recentlv ~n~tiated a mearch programme (WARDA. 1995) whereas C~AT, satited in Colombia, a region where rice is rapidly increasing in importance as a crop. has not.

3.2 Wheat Wheat (Tnniicern arrtlulim) ongmated m southwest Asia from wild grasses, became an Important plant to the ancient c~r~tlrzations of Egvpt, Greece, and Perr~a and 1s now the worlds most wideiy grown staple food (Purseglove. 1972; Kcchlar, 1981).

A lane number of nematodes are associated wtth wheat :n dliierrnt ag:3.ecolog1cal ng.ors A n r ~ a l v~eld .asses dde to aamage bt ?.ant parasttlc nema:~dk:o wreat on a g.obal bass are anmaled I: 7 , 'Sasie: k Freclura? 19971 The major nematode pests of the crop are Angllinn trltici, Heterodrra spp., and Praty!enchiis spp.. Of these, the most Important ts the cereal cyst nematode Helerodera nurnae and the folisr parasite, Anpilnn tnlro [Table 2). H. n:,cnnc, rw~ously thought to occur mainly m temperate counties,

!as now h e n reported lmm more than 31 counnies (Griffin, 19&1). I t IS the most un~ortant pest of wheat in southeastem Australia and serious'vleld l~sses have been rcoorted In L~dia and Palustan ~ n a t h c r ryst nemamde spwa'. H inporn m r s m a n y m the \led:terranean w . 0 ~ ana m no?hern Europe and causer considerable damage in semt.arid temperate enwownmts Angr~inn rnlin ui problem m the indlan subconhnent. Ctuna. m Darts of eastern E u m ~ e and rempPrate ?ern-and ronh A b h and \\A[ Asla '5daFep k h - \ l l a s . 1% Sixo:a, o c. :9&J Inleceve ~uver.!~s ~f L L ~ s?ectes presen! .r, tne 501. lnvaae tne host pianr a ra are carried up to the inflorescence by the growing polnt. The nematodes mature inside galls or cockles that re~lace the kemes, and ca: sur..ve 1.1 i n anhvdrob.onc slate fkr many years Addltsonally, ths nematode u vector of a bac:er~um. Coynt&ctm..m m d l g a n w FV Inno. whch c a w , vellow ear mt and w b p k c e s i 9 m t l y maeases yieid loss (Swamp k Gokte. 1986). Shict law¶ npulahnnseed and aecd c&~&tion ~medura can vlrtuallv ck,dlcati this nematode. The endop&arlt.c lo.on nenarode. ?rai.rlcnch~rs !horn". IS

p a e n d y vnpn?ant n h t a . M a w , and A w l s h f u m tt nl.. 1992). h c e ~ a l rmt-knot nemtode. Mcbdgynt wr, u widely distibuted on wheat, particularly in Europe.

M e a t is gmm in both temperate and semi-arid subtropical regions, in countries of both the developed north and the developing south. Within Europe, nematological research has taken phce In most countries, includmg lhoK of Eastern Eump~, but mort prominently m France and Italy (e.g. Rivoal k Sam, 1987; Gruo & Brandoniaio, 1987). Although a range of nematode species affect wheat in the Un~ted States m d studies on nematode resistance (e.g. Krlorhran et a)., 1989) and pathogenic~ty asoossmentr (e.g. Nyczeplr ct PI., 1984) have kmmnductrd, most rerearch hen has tmued onthe w of wheat in the control of more ~ r t o u s nematode p a b of other cmps (e.g. Ma1 k Abawi, 1980; Kuemlng k Anand, 1991). It is In Australta. where the cereal cyst nematode

Tabla Z Wpr pbnt parasttic nematode pnts ot mandate cmps.

Crops N m a m d n Sympmms

R ~ r e Aj7klrrlcnclutilo &rxyl L r r v a wlth chlumt~c tlpr Dltylrnrilu anf:a:u$ Whue spckles or patches at the b a ~ of

!oung fwlsted leave and psnvler, crinkled. empty glum-

Mr lo idn~nr p.w,nlmb Poor gmwth. Swollen and hooked m t up galls

Dlrtnbulton

Worldtr ~ d a Bangladesh biyannla~ Indta. kladdgaxar Makys~a. l la l land. vlemam klvanmar, Chma. Bangladesh, lndta Laos. Ph~ltppmrs, Thrdand. Vietnam. USA Worldw~de m lowland nn growing areas Wrld%\,dc m upland na gmwlng areas

HirrclvmnnnulO rpp So s p c i t symptoms, general p w r gmwth and delayed L w r ~ n g General poor gmwth. Dark elongated les~orw on mots Poor growth. Cystslwh~te hmales on roots H t t d m spp IH cinclt!s$.

H. or!nde, H O~I::CO~O.

H. xccbn) m e a t Ht tcmdn~~ m m t Pwr growth Cystslhh~le females vulbie

on mots Swcll~ng of basal stem oiscedlinp, fwlrtlng of leaves W nplaced by black nematode

Temperate cl~rnrtcs

Temperatelllediterranrm climates

galls Pwr gmwth Small brown elongate lestonr on mot surface Poor gmwth Cystslwhle females on mob

Mar= Pratylmchur rpp (P bmthyunrs. P :at1 Punct&n chdomra. Htlowlc~a me

SDghvm Tyimchorhynchui IT marlmi. T nudwl Pmtylrnchvs spp I P rat) H r t d m spp. IH. gmnhmsu. H m?hlJ

PC .C. Amenca, H.:..Egypt. India. Pabtan. L'M. W~rldrvlde Gmna l sNnting, non.5peciflc symptoms

Pwr gmwth, bmwn In low on mots Pwr growth cysts vulble on mots

,Ur.odopyf ~ e - m Poor growth swollrr lemr la an ncrr Pear m::ler U?.ouv'yr .rc$Frrr ?wr grow!h. galls or m t s

Southern Air~ca Worldwide Worldwde Temperate climates

Prntyimchvr :rat Poor growth, bmwnuh l e s l o ~ on mots Barley Htkmdma rrmrr Poor growth, cyr t r lwhtr females vuible

on m a Anyuina lntzrl Swelltng o i basal stem of seedlings, twlst~ng

of leaves kcd replaced by blacknematode Temperate As~a

. . galls

Pouto Globadem spp. IC p i l ido P w r growth leaf chlomsu, cysts1 whlte G. mstochimra) kmales vlstbleon mob and tubers Mcb Ido~~" t spp (.\.I. inmgnrb. Poor gmwth leaf chlomsu. Calls on roots. M rmntu) knobblv Nben

Temperate clmaas now worldwide

Trop~cal d m l t w worldwide

Nacobbw a h r Pwr &th, maarybead.ltke mot galls Dlylrnchw dntnuor Small whtle or I~ght bmwn spats just b l o w

surface of ~ b e r , dark bmwn mttmgol tuber Swm potam Mcbkfam rpp (.\I mmgnla) Pwr gmwth, leaf chlomsu Calls on root$.

S. and C. America Temperate climates, Eumpe. N. and 5. Amcnca Trop~cal, worldwide

datortlon of developing tuter mots P w r growth. Crackmg oislorage tubers Lesrons on mots

Rotylmchulvs rm!ionnib Cassava Pmtyirnchw spp.

(P bmchyuu. P @e) Mtbidpqynr spp (M. Inccfmta, M, )mania)

Yam ScutrUonm b d y s

Tropical, worldwide Trop~cal, worldwldr

Galls on mob, poorly formed storage mots

Dark bmwn/black dry mt of Nkn k l o w surbce of skin (irutully light yellow la iom) Dry mt of tuben (as above w ~ t h S. W y s ) Calling of mob a d kncbbly Nbcn Toppling of plan&. YeUmv, purpleand black lertow throughnut nvl cortex Toppling of planb. Yellow, purple and bkck I s l o w throughout root cortex Topplmg of planb, Yellow, purple and black lrrlow throughout mat cortex

W. A h a . G n b t e a ~ S. Amenu

G b b e n . Pad&. C. And S. Am.du Worldw~dc Tropical, wor ldw~dr

Tmp1u1 worldwide, but r m d y P d k , C And S America, C a r i b k m Subtmp~cal/Mditemncan c l i nu tn E Afnca. Camnooh Canary bhdr. Cmtc Worldwide W o r l d w d ~

Darkbmm b m m a d y m e u r n motemex G l b on mob

%d growth, chloms. Calls on mots Tmplcal, worldwde

Cy~u/whi te females virlbleon mob Poor gmwth Roob wlth mucihginour egg m a Stunan& chbmals. Galb on mat

Egypt. Lndia Worldw~de

Egypt, 5. Amanca. Kotu, Indomia. Japan. USA Worldwide

p,ra~ct,sm bv P l a r v l n ? : ~ ~ ~ ~ ~ sp can lead !,- m,r destruchon. r (th ~ h , v e gmund st n p t n m .lf rfun:cd qn-r m chlomts 2nd weld e d u c t l a Cna:tno-ta tmre, I r e to Prr:vknchfes ~ r c :cn,,dered as wtdes~re rd n o I? :Se :'r8reo States o t p n m e n a In nemakne pzrapallv P.zr..:n,i.,,~, c ~ t r o l on maue hare mdted LI $?eta rcte- 01 :X'. a l l tn SOUL, Ahca oi .p tu I W e 13rmn. :3n. Tne ecluprrlsltlc gene:l ~ I . ? I : J . Q . ~ : . ~ . L . I ~ Jrr ,c and Parntncl~cdzri,, are ccrsiJerca pests 17 :he C'nt!ed States B.!~~iob,mi,s ,onglw.dJ::.: . r Fa:tlcula: .r a serlaks pest In the south eastern sra!cr a r e nematode :orrrc. : e s ~ l n d m average vleld inaearcr or 3'. m &n:a : o h o n L Illdoon. !?-5 I r Europe, che re ?a.ze prod-cr~cr na, .ncreased p a t : \ .n recert yean :'.e :elell cyst nematode Honn'rm Q:WU~, can c a m y e l l re>-l::t~% oi -; :O 52'. R I V O ~ . k Cms. :W3 The m m n e m ! x e Dinltrt:i,.,j JIFSQC can also c a w severe I-, particularly whei plant toppling m u l k (Rivoal& Cook 1993)

In regions of the tropics and sub-tropics where maize is a malor starchv staple m bmalihoider agnculnue, in addlrion to ~ r n f v l m c ~ ~ i ~ s p . vanous spectes of endoparasitic nematode canbe serious pests. Generallv verv little information is avaiiable on the status oi nemaldde & b ! m of mane m the developtng countries The cyst nerbtode Hriemdera r a t a considered a senous wst m the lndtan sub.cantlnent and ha8 ;&bm-r&ried n ' ~ ~ ? t ~-d:.iri ma the LSA s w k p & Sara.\.loss 1990. Cn inarr: r: 2 : . 1995 Altnough the nematode a r provoke ?pea: s\r .ptonr o! poor gmwth and cause plant gmwth Rduchom of over 6% m pot experimenk (Snvastava & Seth,. 1981) f~e ld losses have not yet been adequately assessed Acloselv related species, Piincfodrm dlnicnrnsis 1s cons~dered a serious pest In Mexico. Certain s p m a of mat knot nematde, ilielotdogynr. can cause damage to maize, and coru~dering the cosmopolitan dtstrlbution of h genw in thesub-tmp~cal and tmp~cal re ioru nematodes of ths nus are concluded to be causlng yle?d lo& [Norton. I984) .~owever , although plant growth reductions d u e to hl incogttilo of over 80'6 have been obtained in pot experiments (Di Vito et 01.. 1980). fteld data on losses is Iachng, Complicattons anse as maize is resistant to some species of Melojdogynr, and may be a poor host to certain races, for example, M, incognito Populat~ons of there nemtodes dedlne under mane and mcluston of thu m p P recommended in certatn cropping sequences des~gned to control these nematodes on other crops (e.g Baldwin k Barker. 1970: Rodnguel-Kabana, el ~1.1991)

Research on nematodes of maze has been conducted almost oxdwively w i t h the vanous nahonal programmes. Of these bv far the most work has been conducted in the United Stam. Here. in addition to work on the influence of maize on m ' t o d e popthhons of the whole cmppmgrystern then has been work on cultivar evaluation (e.g. Windham k Wtlham 1988: Hashnu d ai.. 1994) as well as on chemical mntml ,e g. Todd k 0a;dw. I s51 A ~ t ~ ~ l a r range of rrvlrch har taken plaoc m Bru:l, was mutmce -lung Ie Bhw & Arron~o l9B9I chcnu:a! cnnml ,e z Lorde.10 a it 1Pn) ~- ...... as weJ as the uw of mave m crop r&cm Ouutde if the' Amencas mmt rrua:ct on n e r d t o d o of maize has taken

lace w t h the MMM. lqrrm+er of hdw and Palustan gwvevs (e.g badef k Sin :9E, Anwar rte !97)) asweu as moie A i l e d Itudies of nematode blology (e g. Parihar k Yadav, 1992) have been conducted Limited march has taken place m vanous munm oi Ahica, Mtably South A b (ug. Jordaan t t dl., 1989) and also Nigeria (e. Afolami and Fawde. 1991) and mm rrcently sgypt (e.g. fknad dal.. 19%).

Wkhm tkCCIAR, m p ~ ~ S ~ b i l i t y for research on m a t u Is shared b e h v n n CIMMM In Mexico and IlTA in Ni eria Neither centre b ever conducted sustained or ngn$ni work on the plant parasitic nematode of the cmp.

3.4 Sorchurn h r g n u m (Syrgirum n ' l ~ I crop of African orrgln s Ik worla s f ~ f t h m o d impurtant gram cmp (Dogget[. 19881. and IS often grown for tdrage and silage Appror~mte ly

~ 3 ~ . ~i the b : ~ .l 5 3 ~ a 2% .!ICa to s0rqn.m :i .n b . 2 . 33O. .. Atr.:r an2 . ir i?Oc. .r :ne 4merccas j.e.3s .r r\tr.ca ~ r d a,,.) are ,?.:$ra,Iy oe ,n :t ra 3.1 :I" ee :ire? t.mes ,water In Chma and the ;\rnencas tbgge t t . 1998) Sorghum g o n e of the mud important cereals of the jemi.arid tropics.

Although more than 115 spwes of plant paraslhc nem.atodn have been associated w!th sorghum in dtiferent production systems (Sharmr & McDonald. 19901 and nematodes have been estimated to cause nearly 7% loss to sorghum yield lhsser & Fmkman. 1987), very I~ttle work ha$ been done to character~re and manage the important nematode pests of sorghum. Thls crop is a ho,t of the stunt nematodes (~vlrnchorl~yndiiii spp.1, the leslon nematodes (Prntyirr~ckus spp.), and also some rwt-knot nematodes. .Llclnnfo~ttc spp. ISharma &McDonald 1990). T ierichur11yncJ111s ntarhnl, T nudas. and : . I L I I ~ I ~ ; in the dSA, and.T ninslioodi and T, urllgrrnr ~n parts of Asia are imprtant. Yteld mcrearec of as much as 35"o aher nematic~de treatment were reported where T martin1 was the dominant po ulatton (Hafez & Claitln. 1982) Lesion nematodes (~ ra lyhch i t s s p ) are Important

arasttes oi sorghum in Australta, rat!, E vpt India, eakstan, Sudan, Tha~land, USA. and ~imba%ive:The mat- knot spectes hl .icmnen ts a pest of sorghum in southern Afrra and pot experiments have demonstrated that it can cause a 56% Imr m yield. Dther genera and spmes aRidarly H~lerodem~nn~b:cnsis. P~rnloii idorus bidlintits. [diincani. Sctitelfonrn~n bli,el~rss!, and 5 c&thrimicdrtum tn West Africa and Hrlerodtr~ spp. in India are potenttallv important nematodes. Although experiments with nekaticides have Increased ytelds of grain sorghum and of sorghum/millet forages by 55% or more O o h o n k Burton. 1973,1974; Hafez & Caflin, 1982). little field work has been done to assess the overall sigruhcance oi nematodes m peld suppression. Of the work done on sorghum nematology, a large proportion has been conducted in the southern United States. However, in ths reglon mterest m sorghum is pnmarily m tts potential in rotations to reduce populations of nematode species, such asHeterodrr~ glycinrs (Rodrlguer Kabana el al.. 1991) and M. incognrtn (hlcbrley k Gallaher, 1992) comtdercd serious on other crops. In other parts of the world, most published research on'sorghum nematodes has consisted bi rurvev work and host records (e g. Germam d ni., 1984. W t AfrI&; Hasan & lain. 1986. India). Research on uathonenicitv and varietal &reenins has also taken place ;n some ~ a t i b n a l Institutes, pnnc~pally in lndta k g . Snvastava & Sethi, 1988).

The IARC mandated to work on sorzhum is ICRISAT. ~ k r o u ~ n ~ l n ~ s.vel In s.n e\. work j ! k m l & >:chnald. 19%) ICRISAT a! p . m . t has nu amre w a r * p r o p m m e on so rgkm nesawces

3.5 Millets Flnger mdlet . j t t i n i !!a1 a' and pear! mi.!e: Ptnnlstll~m xkucum) are gmwn widely :n the .em-arld areal of Afrlca and the Indlan scrcont:nent (Kochlar. 199:l. Ftnger rmllet is an important food crop In the highlands of eaitern and southern Ahica and in Darts of India and Nepal. Pearl millet is used as a grain f w d in both India and Africa and also provide a good source of fodder for livestock.

On a worldwide basw. annual l o s e to millek due to d a m e c bv plant p.aras.t.< nematodes are estimated at nearly 1 2 c (Sarser k F r ~ k r r a n . 198-i Ltitle work has been done on nematode parar.tn of tnese :raps Hc!.cotjkncnits .ndtc:as (spiral nematode), and T uulgirtr in India. M, jnuinrca and P~rntrichodorirs minor in Brazil. Prafylenchss :me and RoryLnchuli~s spp. m Zimbabwe, 6 m e in the Unlted States. and Tqlrnchorkwnchtu SPP. and Hwlolnimiu SPD, m Palustan, arec&idmdar impdriant nemdtode pesb'df pearl millet (Sharma k McDonald. 1990). Information on nematodes arsuclated with finger millet u limited, but three species of cyst forming n e m t o d a (Hdnodrm gimbimsa. H, rorgli and H delvil), and the rentform nemtcde, Rotylmch~~lu nnifomus. have b n n reported as parasite (Se~hadri. 1970: Krishna Prarad k Krishmppa, 1982). Some r e s e a ~ h in West Africa has shown yield Increases tn millet following nrmaticide

m m r n t r gem an^ etn1.19811 M r k has a h m u r e d wttlun lahooal a : l t u b m lndw le.g Tya@ ?to1 1967 Apart ham mmbuhng to nematode s u m p of 1 a n o u cmp,, mcludmg nbllets fe e Stthole 61 Utl~i . 19871 the mandated [ARC CRISAT &s no x h t e w a ~ h q r a m m e on the n e m k d e iamitR of rmllets (%ma & d c b n a l d 1990)

3ariey H~l.?r: .n I'I~ISPW. 1s m e of :re k-7rt1: 3 7a:or gra.n rops 1% prlncipa. uses sncl~de ahrr.a. ippo ~ r a mallng It ra, ~ l r o or m.lled and .red In ba*ed ! ~ o l , The crop ., ;r&n tiidelr in northern Euro e and as a winter crop in he semi.ar:d.regions of the hlelterranean and the Middle last/West Asia.

':ant parasi::: nemalma or 1 q.oca. :ass a n estimatra to 3 1 over o 4 syeld iorr tn 2ar.ev .bur & F r e c h n . 19871 'he nematode pes5 of thu crop are simlar to thwe of wheat. i a;me is rhe'most senous and occurs m manv pam of the vorld (Swamp & boa-Moss. 19901. Another nit nematode, i intippns. affects barlev in north Africa and h e hliddle East/ ,Vat Asia Other nema~cdes known to attack barlev include 'rotyltnchi~j spp. (including P Htor>iri) and root-knot !ematodes I mncluding Mfloidogynt I I U ~ I ) . Research on the rematodes iprincipally H, awnnrl of barley IS conducted m nost of the countries of Europe. Tha includes Scandinavia e.g Andersson, 1976, Sweden; H m n , 1986. Denmark) and I M countries of eastern E m p e and Russia (e.g. Claba. 1985; Carpova. 1987). Most work concerns damage asrerrmenb e.g. Mag, 1989, Romero dai , 1991) and rerirtance b d h g E w m n & Lundin, 19851. The nahonal programmes of both ndia and Paklstan have conducted m a r c h o n the control of i, a m c on barley (e.g. Handa et al. 1985; Pankaj & Dhawan. 991). W t h n the Meditenanean and the Middle EastIWept 4sin. s u n e l work and some expenmentation has been :onducted ~n several countne k g . Romero ct ai., 1991, S ain i l e s b e k Abbad. 1993. Morocco, rU.Hazm eta!, 1994, %udl 4rabia). ICARDA has the crop mandate for barley and has ione much to facil~tate work in the Sliddle EartiWest Asia ,egion (Saxena et ol., 1988) and establish linkages with ,ther research vroerammes to conduct nematode surveys ICARDA. :95$. Gotiever rrucn C A S K h,ork remains io le cone. not .easr .n asserring !he per1 stat,& of the malor >enatwe parasites ot bar.ey o b m e c n !hex ~ o n r

3.7. Potato Potato (Sola~tirrn tr~kmr~itrii orir~nated in the hirh Andes

. . . . Eumpe ,n tnt !6th cen1.r~ 2n.I .n particillr :r . l~wirg :Lc emergem 0: ldaprm var.t: o .n :ne 14th e n t u n :re po:ato has bemme the leading starchy s ta~le of northern temperate countries The crop isnow gnrwi worldwide. In tiop:cal highlands (e.g the Andes. Himlayas and in East Ahcat. a a cool wason crop in tmptcal lowlands, as well as a s p r m g sown crop in temperate regions (Hclrton. 19901 In s u b Saharan Afr~ca. p d u c t i ~ ) n ha, mcna~ed by 1 3 " a since 1961 (Scott, 1993). greater than ior any other major fond c:op except nce and varw

Annual yield losses to potatu due to damage by plan: Damsihc nematodes a n estimated to exceed 1296 rr.orldti:de i&r & F~ckman.l987).Thr malor nematode pcr5 of potato are the cyst nematodes (Clubuirrn mtochimrls and Clotcdrri pnilrdai, the root.knot nematodes (Mclo~dogynr spp.) and the stern and tuber nematodes (Dilyirnchiis sp 1 Lesion nematodes (Pmmicnd~its spp ) mav also carwe yieL ims and the false-root knot nematode ii'v8n&bbtts a h R 0 IS a serious pest m b u t h and Central Amenca ( B d i e clal.. 1993). Potato k t nemtodes orininated m the &dean hphlands but have been spread world;uide during the last 155 years Uones L Kempton, 1982). Globodrra rpp, are established in all potato growing areas of Eumpe and are now found in at least 58 counme worldwide including South Ahica, India. Australia and Japan (Bdiec t a)., 19931. Stnct quannhne measurn at hnt &vented, and have subseauentiv retarded the spread of p ta io c)?it nematode m the ~ ~ ' t e d ~iater, whch IS mnhned to onc athotype of the speoes C mtxhrnsrs (Bmdie ct J! , 1993) \nth h.lr!oidogynr spp and Prntylmchiir spp occur warldwtde, the particular species present in a loc~tion *netally depending on ecolomcal facton M incopiiu u the host imporiant mot.knot nematode species inihe warm woola: M, !wvh and M, c l i i t ~ ~ ~ d i a n found m cooler remom ilaiala & ~r idee . 19901 D~luicnciiiis SDD. causes a drvrot of ;;rat; r.iberr:A..tinough i o r ~ o k .de.i.'spec.es of 3.f,icnr'r:<s are c o ~ i o e r w %ROW pests n Empe. panculorly m eastern Europe. The nematodes feed on sub.epidermal hssues and this kty promote attack bv secondary rot organism. Such attack may conhnue on otdred tuben Uatala &Bridge. 1990: B d i e ct dl., 1993).

BrndonhGumUau 4- -U Enlwnolo#r!s N#m.tdoguU

F i p ~ L Numben of m i o r staff by s p a l a m in sevm ln tmut iml Agricultural Research Centres (IARC'r)CIAT, CIMLIYT, CIP. ICARDA. ICRISAT. IRA. I N .

nematode p b A bibl~ographt prepared in 1 9 3 ltsb 1798 publlahon, on potah, nematorlpz ~Jmsen t,t 4l.lYiPI ~t t h . hme, it was eshmatrd that an e~ghth of all scientific ltlennvc mnrrrmng nematodes dealt \nth potato wmatodei, and XWO cd t k with patabcyst nematdes (tVwlow, 1978). %era1 comprehensive rerlews are at allable on nematodes of potatws (hinslorv & Willis. 1572, Brodie, 19%; Jataia & Bridge. 1990; Brodie rt a1 , 199: .Over the venrs, work on ootato cvst nematodes ha, :overed all ~ S O K ~ S of the pe;ts' biology ana ksst pa:,,.:? :e.at,~nsni{s con:ml measures .n%ertlgrtea . n c l ~ J e :@p rxatun,. chemto. control, the use of resistant ia:tetles and more recently biolopcalcontml. Over the last S yean, wnsiderabie elfort has been directed at the develo~ment of cvst nematode resistant vanehes This effort has seen partmdarly succasiui agawt G, mstocitiotsts In F;ew York State (USA), for example. virtuallv complete control is nos, possible with the use of ~nstanivarieties (Brcdie. 19951 Potato breedrng programmes. tnclud~ne the develo~ment or ;:st nematode resistant vanenes exut m b r h :he natiorr. F:cg:ammes and w i h the commer:a: prtvate % t ~ r 3. -any deve.op& coJnmes In the dweloptng world, many zounhtes conduct research on potato nematodes. In the countr:es of the Andes where w t a t w m i n a mlor staoie. research has a h concentrated Jn the cvst nema:odes :nd.ger 2.5 to :he reg.on e g Femandez. 1998. Ch.:e. Se!o a:: Sarriga. 13.6 Co.omDia. Franco, n i ! 1391 Boliria L!or!:= r: 1.. 1990. Peru!. The national Droeramme In lnd~a ha; conducted research on nematodk orpotato. rewewed by Prasad (1986). Rmt-knot nematodes are major pests of pota!o in Indta and it was here that the earltest attempts at dmelccrng .IIeiotdowr resistance were made Manna k Simla, 19N) &lore mentlv work has h e n conducted m the U ~ t e d States 1e.e. Ineham;l dl.. 1591) " >

wilere the S P C ( ~ . .\.! :n.::mui 3 : 1 ~ r n g concer O ' B a ~ o n c 11 1982, Reseam or 31g.m::. -. j3p nai K N ~ mc6t1) in Ewape, in paihcular m cistern E G p e (e.g. Komobis & Stefan. 19911, %me work has also been done in South Africa (e g De Waeie el ~1.1991) Drtyie~tcl~~ii spp are consideled serious pests of sweet potato in China (see sectton 3 81, howev&, notiung u k n o k of theu lnnuence on S. lirbmgum in China. Narobb~~r abernnr is being studied wtthin the nahonal programmes of vanous buth Amencan counma ( B d i e r t 41.. 1993). The IARC mandated to conduct research on potato is CIP and, of the international centres, CIP has conducted the most work tn nematolonv, and has been the orJy Institute to recogntse the ?.~c~?;.ne adnin~strattvely \with a Department of \ematologv and Entomo.ogy~ At one sane. ; number of nematolopats were included in the progra&ne .Fig 11 and over the:ean CIP has generated a large amount of m a r c h :nfonnanon on vartov aspect8 of potatonmtobgy ICLF InB. Jaua k Bndge. 1W). Mvch d 'h work was c & d d in close coUaboranon rnth nvanh group m the C ~ t e a States or tne C ~ t e d kngdom Alarge part of tnis effort was d~rectrd a: germplasm collect~on. s c w n t n a ana evrIuat.on. aPd .-.I hns con:r.buted significa;tly to the successful development of the cyst nematode resistant vaneties reierred to earlier. With the nmgnition of the pomrtiai of potatoes in the lowland tmpbopicr (e.g. Lmmonds. 1971), the importance of research on root- knot nematodes w u rwogntred ljatala & Mmdoza, 1978). Such work was developed hrrther ie g, lwanga el PI., 19891 a¶ a component of CIP's overall efiorts in this area. Recently, however, the CIP nematoiogy programme has been much reduced (CII: 19%).

3.8 Sweet Potato Sweet pollto ( I p m a Lt4h5) ongnated m the New World. and was being gmwn tn Mexiwand other parts of hopid America in pre-Columbian times Sweet potatoel are prewntly grown throu hout the humid tropics and many sub-tropical regions ( 8 u r q k . e . 1968). Globally, sweet

crop s also of malor Imp;rtance In Iapan dnd Taiwan Sweet potato a k o m i n g tncreas~ngly im onant as a subsistence crop ~n Afrzca, p.~rtrculnrly in the &st and Central Afncan Highland countries of Uganda, Bcrundi and Rwanda where a ~ u a l per caplta consumption may be over 100 kg (Scott & Ewell. 1993). The Americas ~roduce about 3 million tons aer year, rlme 0.5 rmlLon h~woi>vhch a r e ~ w n m the wuth;; United States.

The major nematode pests of sweet potata are !vlrlo~dopvtrr spp., Rotylotciiulia mifbnris, md Pmtylniriti~s spp.. ~tt~l&clicili~s d i p o and D ;Icitnidur Are reported as renous pets tn C h Root-knot nematodes are distributed ivoridwtde, the most important species in sweet potato growing regions being M. rnco~n~ta and h.1, latntttra Rorylcnchirlil~ nn1,brrnrs is found throughout the tmpio md sub-tropics (Siddiqi. 19R). Among the species of Pnitvle~trhiis known to attack sweet potato a n P cofiar. P bra;hyi~rilr. P pmrtrans, P ~i$l,itls and P ZIC. Mclo~dugynr spp. fail to induce the prominent galls on sweet potato as they do on many other crops. Netther does R. mnlJormts induce obvtous root symptoms. Consequentiy. held awsmenk are inadequate, and iaborahlcy e x a m t i o w are required to regtster the presence of these pesb. TWO factors may influence losses caused by Melotdogync spp, and R, rm@rmts. Plant wth and the weight of rook harvated may be reduced. tion on ally. phpiolwcal shews assdated with nematode parasitism can induce longitudinal m c h g of mob during development (Clark k Moyer, 19881, These cracks become deep fissures with a surface of callus or periderm, and the market value of luch sweet potatoes e reduced. For example, in North Carolina ytelds of sweet potatce grown m sandy soils mfested with M. titmgniln were up to on+thvd that of nemahcide treated lots AddtHonaUy. there were 18% of cracked mob in mfr?tAplo& compared to less than 3?6 tn treated plots (Neilren k Saser, 1959). Pn- plant nemhcide hahnents of ,M, tnmgniln d a t e d soil both doubled the vield of marketable sweet potato m t s and a h reduma t c pro~ornon oi xaclud t&rs by ~ve:JO"o ( a l l rt 11,1388, S~m.iar benckts can occur u,:th the contml of R rm&nn~s In rwo vean cf field !eso witn nght s w m potato varieties, nenat.ctde treatment3 increased ):eld overal: by I O D o ane red-:ed the ercenta l of cracked sweet pota!oes from 270 to 21". C.u! L Wr1g\i 1983, Tuhr oamge m\ be of !mpot:arce In auarlng ecommc .msm (C:? 1992) and nematode ef!ecis on qua..'y and grade Johnson zr al. 19921 a n oi s~phcance m deve.oped munma The imponam of such fadon in other agricultural sptpmr, where the cmp m y be viewed as a low status food, or is rown for us- such as animal feed (Clark & Mover. 1988; k o t t dr Ewell. 1993). needs to be assessed The bist studied lesion nematode u Praglmrhvs rqpar a uriovs p u t of sweet potato .n Impan Here sign111cant m ~ e s mrv occur parttcularly on volcan~c ash wiG, and although no data are available, they haveken serious enough to wjrrant significant wed pok'to breeding p r o g r a m agalnst this n m t o d e (Muwnine & Lkamoto. 1979; Suzuki, 1989). Ditylrnckiis spp, provoh "brown nng", a brown to brownish black layer wtthin the storage root. Eventually the entire rwt may become decayed, especially following s ~ o n d a tnvarion by fungi. The diseaw is generally considma)a storage roblem. No information i, avatlabie on the incidence of t fe problem in Chtna, the world's largest ~roducer of sweet botatoer. althoueh it IS the sub~ect-of dant health mana&ment f ~ i & CU;. 19921 ana bmdtng kbm (Xie ti 01. 19% l n t e ~ a t ~ o ~ a l l y , mcdt nmawkgml mearch on sweet potalar has km conducted in the Utiited States, which prduces Iers than 0.5% of the world's output. Work on Mrluidogyne spp. and R runforma has oledominatd. Nmutde uouvlation dvlumiu. studia on iathcgetut and brecdtng'& r a ~ t a n c i Iwse taken place .I, 3 number o ~ u n ~ v e o h ~ i e r 2nd instttuter in tne southern Jtater since the earlier part of this century. A significant component of research in the United Stater has involved

,he evalvatlun of nemvticidrs Such work cor.:mues and

tn rt al. 1995)) In Afnca. b d m g work has takn place m South Amca (Kinmer el 01.. 1993) and work on the nematodes of sweet potato has been publ~shed from Egypt ,Kassab & Taha, 1990) The IARC mandated to conduct research on iweet potatoes is CIP which took over respun~ibilitv for the crop wlthin the CGIAR from IITA In 1966 CIP, i98.8). IITA conhnues work on sweet potato w~thin the context of Uevelopmg m t and tuber maps w i t h nahonal omgramma. 6- awuming the mandate for sweet potato, clf'has mhakd basic screeninn of its eermoiasm collect~an for reststance .o rnor-knot nimatwispec;es \! ..::op.r~ In: '.! :,anrca CIP 1998. 1939) More recent.) i.cn hers nd: .rta.vea :?.:aDoratlon wirn natlona. .ns: ."its :n Ch:ra .o screen ermplasm for resistance to the storage rot nematode.

!J dntnidor (CIF, 1992)

3.9 Cassava ng,nanng .? troptcal Amer:ca cassava Uac..::: ?m,.rnro ,ow grown in ail t:op.ca' :eg.ons ?o:al pr:-;:,on is

,ttmated at over:50 m:l.:cn icn, a.1 .n tne :est.optnp, :ountrie. Introduced to Ahca by the Portuguese expl.ires n the 15th centurv. 11s cultivation has develoced rauidlv Pu:seg.o\e :965' .r ., n x Jnt c: ::e :or:lie,+ s bosi ?:?nart crops b.th an ar--.-.a. p:on,:!ion r e\:rss c i 70 million tons i n some countries of central Afr:ca, cassava :onst!tutes 80% of the per capita consumutmn of starchy . . 6rap.e Braztl, wi:n 22 ttul.tcr ern per aMLm a::s--ts lor ,early !?Po of ~ h c pxdunon ?r Lann.&?nenca P a r i a o r u 'ap.2.y grou'ng .n mportance 13 Asia, now 2roc.r.ng orer X)miLin tons per aGum.

:arsava e h a t to a wide rangeof nematodes (hldariey rt nl., 1983); however, relativelv Ilttle work has been done on !heenematodes or the losses they may cause Root-knot rematode, in parhcular M iricognitn and M la~nn~ca found w~dely on cassava are the most hportant. Other important aiant.uarasit~c nematodes associated w ~ t h cassava are : hcnyans R r m ~ h l r an2 :re tam xmatde. :::.!Z.'onm ?ran)s ,M&rley n 01, 1983) khodgn work has srDwn chat he root-knot nematodes a n capable of causing signihcant .eductiors w m t weight (Caveneu, 1981; Cmzoli k HiIdago, ,992). nematodes have ro t dwavs been rezarded o a mior ,o~'marnt to cassava produc:& uata.a'kr Bndge 1 6 ) . iowevn: survey work q m n g xvm field s p ~ t o m of w t - h i d a m e m assava Skora eta:. 1988 Bndze o d 1991) su~ecsb k t serious 1- mav be acurrinc certain - a m m e . At prexnt very 11:t.e reseaah s cond~::ea on the lematcda of ~ v a . Some eraLla2on of ranela. L!Yerences h resetarbx to mot-knot nematodes and methcds of contml las m n conductea m Latin Amenca Cmzoli k H.laago. 3%. .Wma n d . 19%). Rncarcn programma on cassava rlbt In bath Brazil and Thailand One may nolc that

nvestigations on plant-parasitic nematode will be ncorponted mto t k pmgramma as the ~ ' 5 ~portance nueases

b t h CIAT and I[TA have cassava among their mandate mps. Although CIAT has a malor breeding programme for be improvement of cassava ( Henhey & Jennings; 1985; /gklas & Hershey 1994), suvephbilliy or rase to p h t - )arasitr nematode are not ~ncluded in assessments. IITA, with 3 -to cuvavlg that pan of h e world w n e r w v a uJ yrumed ~b greatest importance as a fma crop Ms ah Played a ma* I& in cuyuiia march. Work on a e m y 'nd pest contml have been conducted for mani.vean..

5.:re,. .- rnc r~,>l .: ;3i clmtr ,. ,,f me ;>,.I r nei.vbug ? a .?nr:ltr 9 1,1.*11 has reeet\,ea .nterna. :n>. recumitton CCIV.. !SY-D and .mpmvea :.lr*ltJ \.Irene. anr& from

the breedin programme are having a signihcant impact m the region IBahiya d ill., 1994) However, although work at the lwhtute has shown that mot-knot nematodes could r a m . -. s~~n..!.cari reA~cr:ons :n :oat vteld lCa.erers 19JI and rre :mportarce o i ~n:or~orat.ng numatvde reslrtance ."to ~ w c l n g p m j r m e s ha, M n m o m % Ha.--- r: a. :989. no iurther work on cassava nematulky has as yet been done.

3.10 Yam Yamr (Dioscorra spp I are one of the world's most widely grown crops. At least 10 species of the genus have been cultivated in Ana. Amer~ca and Africa ICoursey, 1967). Worldwrde, yam product~on was estimated at 30.3 million tons In 1991, well behind that of cassava and sweet potato (at 132.5 and 124.3 mil l~on tons respectivelv. FAO, 1995). However, over 90% of the world's yams are grown i n Africa. In part~cular in the "yam belt" stretching from Sigeria to the Cdtr d'lvoire. In this re ion vams are of major dietary, and also cons~derable cu!tur;l'importance. Yams are also important food crops in South.East Asia, the Pac:f~c and the Caribbean. The most important species of yam in West Africa w D. mh!ndnta.

On a worldwide base, plant paraslhc nematodes an estimated to cause nearly 18% loss in yield of yaw per aMum (Sasser & Freckman. 19871. The most imDortnnt nematodes of vam - -

are .':i~rr.lcnraa bn.iys and .!&.b:dofrnr s ~ p . tn part:c~lar .X :r:ogn.ra Tne .-en nematoce P 6frmr :s a ;est o i yam s ineCanbbc&* and tne Panhc B n d p 1956 Csata.Be:~ford & Brathwaite. 1"; latala & ~ridnr1990) 5, brndvs causes a dw mtW&rease of vam tuben &a ttumaton endooarmite me r.emarode e-ters vou-g growing :L&n a;a fed; .n thc' t:,sLes o i the a-ter 1 - 2 cm Feeding :s 3r :ne ha:ves:ed ?ort.on of :he ?!ant and vieia loss LS d:rcct.v related to the damage caused. It has b&n found that 5. biadyr damaged tubers mav weizh 10% less than healthv tubers and the amount o(d~seakd tssue discarded In load preperatlon may be 20% more Losses by continued feeding of the nematode during the storage of yams, articularly when asmated with h g a l d w ~ , reached &Iws~ (Adenyan e l nl. 1975) Control methods have not been develo~ed. Al l !ne malor vam specin are .usceprible to 5 :r.i.fys a-d :ne nematode has a xide range o i n,ierna:e FOSIS rest:,ct.ng rne scope for failow or cnrp rotasion Botn cnemcal conml and hot water treatment of tuben have been evaluated (Bridee. 19621 but theu auulicab~hh. for small scale i a m b h m t k Rmt.kmt nemaibbes anaci both rwts and tukn of the plant As m.tn 5 ornlys the malor c a w of .oas ,s d ~ e to anrckof the tubm b g e u las due to abohte yleld lac than la a reduction m mahtablcvslue due to the abnoml, warty or knobbly tubers resulting from root.knot attack (Nwauzor & Pawole. 19811 Rmt-knot nematodes have wide hos: ranges, restricting as :n the case a/ 5 br.74~. the scope !or :ontrol by h..ow or crop rotation There are reported d~iferencn in susceptib~lity io M. incognrin and M, jn'vanicn bebeen ddermt suecies of vam [Adesivan & Odihim. 1978. Jatala k Bndge, 19b0). In t<ose ig io&of Central ~merica' and Asia where P colfore occurs, the nematode a found commonly on y a w Uatala & Brid e 1990). A migratory endopararite like 5. brpdys. P mRar akattaclu tubers, in the field 'd in rtoraee. A duction in thc edible ~ortionr and in ma:rctablry cahlsult heresy attacked matenal ma\ !ad w sprout ( b r e r - k k f o r d & Bratnwaite 1 9 7 Al u ~ r n S bmdp and rcot-knot nenumds. P cofiat w a H lac host range: Most research on nematodes'i.f yams (mainly P cofeael has h e n conducted in Central America and the Caribbean. Work has a h been done in Asia, including India and Japan. The review by Brtdge (1982) referred to work conducted in Nigeria, the world's bi est pmducer of yam. Since thb period. however, publ i~h~research from Africa on yam nematodes has been negligible. The IARC with

,Vvr~~crt~~l~~tcol Abslmctr 199: Vul 66 No. 3

the mandate lo conduct m ~ i ; h on v>m, is IITA, but little research on yam wmtolog): Jiart from snmeeari!, swcys. has been reported imm the lnstttute. Inn record of work aublshed bv the Inshhite (llT.4 1992) wme 3 citations deal ktth "arm. but onlv one of the* (Badra rt a1 19801 u devoted ,~eclhcal!$ m nematma Hd1.n er 1-e adlnon are awatv of ne* deta ~ e d studtes on rer ,.?ICY r 1m !O S bmlyr and hiddqyu at IITAmd it is hop4 that thw work will d d o p and coihnue

3.11 Banana and Plantain Ban&% anc ;.artam . . I . & -:: are n m n u ~ 1 2 - w ~ d e n !mpbca. reQ.ors princ.pa..b .: .:., and JnJ, nhere ralnf~l l LI In exce, r !.L5 n r r per r <>- hlo,t c.>rr.moniv qmwn varieties are tripioid hybr~d j a i the naturally o&Grin sped- bl. nn~rntrwfrand M b".?:jirne 1Simmon&, 1966) T& exmrt trade bv i a m piantahom reorerents leu: than 15% of - . the esttnatel annda. ?rod.:!.'? sf -6 m..' on ! 3 ~ (Pnce. 1%) The t st malonty of pm:.:::on a by sna.b,olden and svbs~srence :rimers Ir. :he :6'. e.ol:nq k.0r.a IT Afnca. In particular. piantam in the !crrland tbp~cs, and highland bananas In hlghland East .Air:ca are tmporlant crops i n smllhoider agncultwe.

Estimated a-n-al y1e.d .osre, :auses 5.v ?.ant parasin: nematoacs to jamms and 'a-'am k ~ r l d w d e approach M o o : b w r k Frecrmar. 19!' ine most ser1o.s nemtaue pest of bananas and plantains a the '"oumwtng nematode" Riulopholiis sirnilis, partly due its status as the mapr nematode pert of export plantations iColren k Quenehewe, 1990). Riulmblm mnitlts. md s~enes o i Prnlvlrnchta. are ~r inc i~a l lv spre;d on i - k t ed ? . a n ~ g rlie:~a! 'Tre ror.dw;ae siread oa R sm. ..s s srrr%ourea to 1% :.jsez:na:ion o! tnfected : nnMg rratenal. prc.?aLv :?-re?.= ki'h ve estabument bf ?.an1a::3.75 :or the eip?:! .ra:e are: tnc .as! centdry Pmrylrn: :.s :,*at a h has a \.>:!awide dlsmbunor and has probablv been 53RaJ LI the sa-e rav .Another P~lqirnchus rx ies ,> ~ d 4 , u f w a :r .A-ca in !ne hgh.ands of Eat Ahca andm Camemn n tre Caran. I s . k7~ a.ld m I few luca.lncs .n tne \ldi:er:anear :! s 16~ortar.t princ~pally tn those areas o: East Afr.ca wnere banaras FroVldP a stafchy s!aple Hdlco:,;rnch~ts nb!ti::?:::i.s :s a.so i o ~ ~ l worldwide onbananas iilrlotdo~ne spp ipnnc~paiiv M. incofnitn and M. jnvrn ic~ aiso occur wydei; on bananas and filantains. Available data. reviewed bv Gorr.en and Quenehewe fl990) suggest that yield mcreask in e~port bananas of over 1W% can result imm nematic~de treatment to control R stmtlb. In lndia yield losses caused bv thts spectes are estimated at 30 - 40% (e.g. Koshy. 1986, eddy. 1994). The spiral nematode (H, mtditinncfte) a c w s widely m Afnca. Asia and South America (Bridge, 19931 and m y predomirute in mixed oo~uhtlons with R. sirnilis (Gowen k Qudn4hervC. 19901. In'Nieeria, nematicide treatment of ~lantatns infested pnnc&aily w:th H mialrictnci.rs ~ n d .i! jrwnirr (Badra and Cavenw 1983) Ika to m m a m 13 bunch wecght of nearly 1001. In Indm. H mu,rtonnts rduced Danana tield by Y%

Until recentiv research on klitss has concentrated almost exclusively on problem of the export =tor (Buddenhagm, 1993) and banana nemtologv fonued, a l m t eulusively, on one specta (R. rtmilir) and pnmariiy on nematicide testing. The development of improved varieties with nematode rmYance s stiii awalted, a d~lhculty bemg that trawferable rmuhnce has so f u onlv been found fmm one source and only agamt R. simiirr (Pinaha. 15%). Little breeding a r t h u thus far been directed towards other nematode specie. The IARC that assumed the mandate tor bananas and viantains (in 1987! is IlTA In Airica, the continent where ihc cmp WU- tts pkit importance m imd ucurity and whaetht t thrskenwnneworkdonecmyle ld~cruwd by nmutodes (Cavermr & Badra. 1980; Badra k Cavrneu. 1983). IITA's plantain breedtng rogramme has httherto mrenhakd pnnnpallv on siytoL (Mymsp,mnd~fii-l. Amntism ti being turned wa rd5 nenwtoder with Illh

-. . hnt ,op : a~:cmFting mhtab trn me rel~nvr . r w r d n u t nemtosz .>eon .n ,mai:no.aen' plantam r 4mca Sum$: work Is r r ~ l e ~ e.e(r.neR. p a ~ ~ c u ~ ~ r ~ y In &.a l r n m most bananas and plantains are pmduced.

3.12 Cowpea Cowpe~ :':,'r~n ~~npirict~liif.~). is of African or South.East Astan orlr : i The biant shows wtde varietal difierences and IS miiniv erown lor hts reed althauph ~t mav s i s o k . grown rs r reietable or for ;odd& &&in rh; ;;opt;, subtrop~cs and semi-arid tropics. some 90% of the world's annuai c r~duc l~on IS in .Africa. with substantla1 amounts also be~ng grown in India and the Unrted Stares. In the subsatence farm~ng of the developing worid. the crop 1s well sutted to ratnted seml.arid conditiotis where it IS often intermapped wtth cereal crops such as sorghum and mlletr.

Keld loss* due to plan1 parasitic nematodes a n eshmrted at over 15'9 a.orldwide (Sasser br Freckman, 1987). The root- h o t nematode species, k l t~icognth and M, jrwntm, a- the most serious pests of mwpea worldwide (Sikora and G m , 1990). In glasshouse experiments, growth and yield of cowpea !\.ere reduced bv 9096 by mot-knot nematodes (Shanna k Sethi, 1975). ~ i e l d tnalr have shown ain yield mmases oi 14% in nematidde mated plots ( p a 8 1 ri., 19901. I M o n can a h mmase the incidence of b r i u m wilt in wilt resistant or tolerant culhvan ( H a w & Few, 1991) and has k n ihotvn to reduce rhvobial nodulation and nitrogen hation [.&! r l al., 1981)

Other t a ?r nematode pests ~nclude the p.geonpea cysr nematode i d ! r ' c d r m ras~~l i o a d mamly tn inc.a Korhy k Suamo I?-: . and R nnikrn 8. I worid.w~ae pest of mwwa whlch'has been tnvertinited In vanous counktes includine In3:a ,G.:!I & ~aaa;!380,, tnr Unitea States {Heald & R>bnw :357). Brazil 'Pon:e 1387'. Egypt tBadra k Elpdr. 1979). Ntgerta (Egunlobl c1 nl., 1986)and the Philippines ~Castillo rt 21.. 19Tn. Published mearch on c o m a nmutcdu and their conhul has come oredormnantlv h m the natiorui ~nsrtlutes 3: lndla an1 t h i ~ n t t e d Stat" In Inha, %wey worr ie g k n & Du pta I9i6l p~hoge~c t l v ~~.aies and resstmce s m m g K a n kin 199Bal nale been done Work on nematode.plant relationships, ( e . ~ . Simhi k Daseuota. 1993) int;racuonr with oiher o6anism (e.n. ~ a n w i r r: I.. 138n and on nonchmcal meth& of con& te g Khan k Hurain 1988b has also t a k a p.rce In the Unitea States. publ~ned rewa~ch ha1 ohm invesngatd the mie of cowpeas in overall studie of a articular liematode swdes and its mnaeement b e . Soudrdr k Priest. 1973). & addtoor.. resutancc"saeenmgieg S w a ~ o n k Van Gundy, I9&) md p in t ~medmg .eg Ferry L h, 1995) nave bmconduded. - -

Within the CGIAR, the cmp mandate for cowpea is held by Lhe IRA whch has conducted a substanbl mount of rrvateh on the crop, encompasstng as ects of cowpa agronomy, breeding, and entomology (II?.~. 1992). Within Nigeria various nanoml inshtutes have studied mwpea nmatology, including vanetal m n i n g (e;k. h l y e t p e and Ogbuji, 1991) and nematode control (e.g. gunlob1 and Olaitan, 1986). Although some of thu work w w in colbboration with IRA (e.g. E un)ob~ etal.. 1986) and the institute has conducted grnnp&smmeRung for -to& raistnnce (c.g. ~avenar, 19751, no sustatned research programme on cowpea nematcda ha been developed at IITA.

3.13 Soybean Soybean, iS!yc8ne m x l arlglnated tn China and tne fin! domahcanon a thought to have occumd m e MOO years aao (Hvmow~tr. 1970) The crop has stnm att~tned malor ikporthnce i n the agrtculture (hnd culture) of the region. During the 1st century cult ivam of tk crop has spread and

ncre~ed, most notably in the Ln~ted Stares and ,uvbeans rave become one of the world'i mdtor foad crops hnd a ,~@antmmrmdity m mtemahonll Zade \\mid *loduction ww e x d s 136 millton tons per yea:, of tr Clsh do. a horn he C ~ t e d State. with the world's second blggert mducer, hazil, producing over 24 mllllon tons per year thins (16 wllion tons). k g e n h ~ (11 nullion tom), and India (3 d i o n m) are a h nupr p d u c e n IF.40,lWj).

More t b n 100 specie of pht.parasinc nematode hue ken issocnted w ~ t h soybean i5chmltt Ji Soel, 19941. the maior ,est species be~ng Hetcroilrra j!!::r:r.s. 21i:L,~.t,>~vnr spp: &I incognita, M. awnrm and .L!. .i:..ir:tcr and R .m~,forma. bee nematodes are eshmated to cause a ~ v a i rield 1- ,f over 10°'. to soybean on a worldwide basis jasser k :reckman. 1987. Over the last20 rean bv iar the greatest cntrib.tr!on to soyoean lema!?.og: ias be+? -ade by ,urrerour m a x h groups in :he in.:ec j t d : ~ L.ZR work us row lanplt concatrated on tnr 13% bean osr iemarode, i plvc;nrs,~considered the most jer:ous sl&ie ~ e s t of

< . . . ovkans .n !he countr) Oi 2s: a-a ::,paw l?,ses overat!. !99. are attnP.ted ro "nemat.xe, a-: ?te: nd.i :i these to i ?!"ones alone \I.!rmnm :95c % . > un-c;. -re:arn ~a;ieveloped on this nematode, ior example, one in einht tcrt:acts presentei at a re:er. :rre:en:e 53V. :99j. .~n:erned H f.?:.nts Al. asaers c: the spec.rs arology

~r.d nat.parasite n:ationr are berq 2:-d.eo a?: rnutancc ,reedinnis being actively conduded In manv states. The - - . ,wcies a of sucn importance tha! a >mi s~.hc3Jv debored 6 H ,-tyoncs has k n puo..shel Rgas & ;\ra:n'er, :992. twarch on 3 ?.,ones Inc..alrq :.^e c:ee2..-q 2: nematode -eslrtant rovbeiivaneties n also beme donein China and apar where :ne :rap, an2 :-r - r r d : xe are :?nj:derra a Save arlginated e g. Lin :;.,? \a&a.nu:a 1.: 1 . . 1982) ?search oh~rlo~dogyne, com~dered oi mneasmg unportanm o soyban pmdumon m the worid'j wanner r q o m (Schmitt k Nwl. 1984). has been conducted again pnnc~pally m the ,mted Stater 1e.g. K c e m g & Barker. 1992! but also in many ,the7 countries includmg India !e.g hleena k bhshra. 1993). Brazil (e.g. T h M el nl.. 1988). Sigena (Carenerr, 1975) and Egypt ( e . ~ Mohamed & Elgurdi. I W I

A1:h.n the CGIAR, tne :rop -mda:e io: sctbean .s he.a ,r llTA Although at a Irttle o%er 5X SC 101-6 per \ear. Ahca ticounts for less than 0.5% of world ~roduciion. the crop ci :onstdered tu havegrea: ;o:enr.3' r she :onrlnent ;IITA. ,390. IITA 1391' Altnougr some 2sea:cn ias recently been :onaucted ~r E m t (e n Yoha-ea k E~L-d.. !W v.rluaUy l o work on thynematodes of soybeans has been done In 1ub.raharan Afrtca. Apart from bn initial yield loss study .Caveneos, 1987). no work on sovbean nematodes h a h e n

" . 'lgeonpca (C?,anu apn l ongmtea m Lndla an;! ? m l ) It r gmwn m over 50 munrna I! .s ar mportart F a n qunc n the semi-arid tropics ~ i t r a c u i GO4, of rne worla

:entnl and eastern India (Sene k jhe.13 lk' Tne m p u slsoof co~tderaoe unponam r amca. Lam A m n u and he Canken. of iheduracter~ho of pieeonwa IS the iivenity of IU urep In dL t l on to a n gnu;. h a n d nav be coluumed green as a \egetaale. the .earn MY I&!& fodder and me shmr -uc a Sea.wooC F3r 'h reasons. and the genetrc diversitv aratlable. the crop is mldered to have signifiml worldtclde potenha1 (New k h k . 15% Rema~ndan. 19901.

4.though many s p a of pcant.Da:artttc nematodes have x e n found aswctated with p,g;orpea (Sene rr nl 1996) ,he mapr ncmatodc p u a n . ~ i t l o J ~ ~ p n r I M !ccqnlP and U jrvaatca,. Httrrodcm caran: an4 R rsl:'orm*, Sharma 'td. 1992) bWnJogynrspp and r7 rm.@forrmr an aslnbuud rocldw~de. and H upn l hrr x> 11: wen founa :n rho Indian

subcontinent and in Egypt Hi~ruever, with plgeonpea production bring cnncentrnted overwheim~ngly In India, this species M comldered the crop's most serlous nematode pest. The plant parasltlc nematodes cause an estimated annual loss of over lj0, In pigeonpea yield (Sasser k Fleckman. 1987. Sharma ct ul.. 1992). Nematode parasitism may d w l v aiied plant gmwth nnd also reduce the formation o i ih~zobi i l nodules on ruot systems (Mohanty k Padhi. 1987. In addihon, ~nteract!ons between nemalode parasitism and ~ncreased tncldence of Fusanirm wil t have also been reported (Hasan, 1984: Shnima k Nene. 1989: Singh et nl.. 1993) Research on nematodes on pigeonpea has been conducted largelv withln India. This has been both within national ~nst i tu tk and at ICRISAT, the [ARC mandated to research on pigeonpea In addltion to surveys (eg. Velavutham. 1988a), work on the biologv of the major nemhtodes, on host-parasite relationshiis (e.g. Patel k Patel. 1990) and pathogenicity studies and crop loss assessments (e.g. Mohanty k Padhi, 1987. Saxena k Reddy, 198i) have been conducted. Application of nematicides m H :ajan~.infested fields results in a 20.3096 increase i n pigeonpea yleld Screening ot pigeonpea for resistance constitutes the major element of published research on plgeonpea nematode mnhoi (eg. Patel et al., 1987; Velayutham. 1988b: Shanru, 1395). Field evaluatiors have h e n conducted bv various national research eroum wlthin lndia 1e.e. ~hvjcnandra t r 11. IC'361 conirol keas.tres er.a;uatea sc.ude chermcal mntrol 'e g Liu k Bhanl. 19%). ICNSAT's work has con:entra'ed on the tnenttflcat!~n of nematode constraints of pineonpea. identification of the distribution and role of nema"tod&i in the modification of fi~sanam-wilt :o.sra?ce. and :he deve.opment nematode managerrent practices S L C ~ a= host-p:a~t res.stance, c-.:-ra8 ?rac!.ces, and natural control (e g Chauhan el nl., 1988; Shanna r l al., 1992; Shanna d a/.. 1996). %me investinatlons on piaeonpea nematodes have alro taken place outshe India, iohbly'Ln East Africa a secondary centre of dlverslty for the cro (Saka, 1985,;~tlloclw k Songa, 1993). Some of this work [as been conducted m collaborahon with ICRISAT (Daudi rt ai.. 1995).

3.15 Groundnut Groundnut (Arachn hypognea), a nattve of South America, is grown wrdely in 108 tropical and sub.tropica1 countries. Production exceed5 28 m~llion tons per amurn worldwide.

among the malor prob,cek of groundnu: Sigeria. Senegal and the Sudan are malor producers ,n Afr~ca The crop u gmwn at born rubrJtence and conuneroal seveb for t u 011 and u a pronm nch m m e of food for hum^ and I ~ ~ ~ u t c c k

P h t pamihc mtcda are wnmated tocause annual yleld .asu of 12% to m u n d n d worldwide (Sasder 61 Frrcknun. 1987). The mosi~mportant nematodes of groundnuts are .\.lrlotdoqynr spp (p'rinclpally M a r m n r i a . ~ ~ hapla and .M rwnta) and the lnion nematode. P nrnchytrnu i s h a m k M:Donrla, 19901 Ln aadtnon to anackmg mu, P b m c ~ u w also ~nfects and weakens the Dee andbods ( ~ i n t o i & Bauiard. 1M) . Other ncnutodb& &mid& Imoortmt n s ienf r ceg~ons .nclude. ~rlon'olo~mw long~uilantu; and Cnconomdb omin In the L ~ t e d stat^ (Minton k Baulard. 1990). Apklmchoidra rrackidis. Apluramntvlenchiu rtraterntur and Sc~ttrlloncmn rvv. i n Wut brfr~ca 18rid.e r t nl.. 1977: Germani. 1981: t i r k a n l k Luc. 19821 iny yon k ~auiard.

~ .. .. - 1490). ~~Uncho.rynchus bmil~nmrus i n Indu (Redd) r t 01.. 1964) and Dttylmc,iw afnmnlu ( I D dnir~rrror~ in S Africa iDeWaek et nL.1989). A; vet, little nematode rescitance has been ~dmtified in inmchii kjpisaea germplasm (e.g. Joshi k Patel, 1990, Smith et ai.. 1578). although research work is i n p rog~ l s (e.g. Holbmk k Noe, 1990; Smith r t nl., 1978; Mehan d al., 1993). Mort research has therefore been directed at chemlcal control and the use of crop rotations and soil

t ~ s x c n c c n a ~ c d pnnopall\ .n tne :.?L?'- n of wntem and esltern E~rope In the Crt.c.! K.ngc YT cnem~cal conrm! merhocs le g tVn.tehzx & T~te :*37 ana France reslsra?:e Kreenzng le 3 Czibe. L Lrrlercq. 1989. t a w k e n conducted In manc a-ox reg.. measurn s4chas Ihc uu ~~Icemfieu claw *J '2: F.~nnn3dre J& r the .mm. of the pest le 1 K%th :A3 W s . ~ e E - m ~ t , hba bean nematodes have km mveshqated ~n \anou cokmn, pamcularly m Egypt where attentkn has been d~rected at the mot-knot nematodes (e g Gazar & \lorad IPSlr

The International Centre which I , mandated to condur, - - . . . . . . - - -. &arch on faba bean 1s ICARD.4 Survevs :onducted by ICARDAand ~ t s collaborators les DI ~itd.*! .J!, 1991a & b) have idenhfied nematodes attackml: faba beans In the d o n . %miexpnmental worksuch as cuihvar -rung (~anounik e! ul , 19861 and the evaluation of cultural control techniques (Llnke ct a1 . 1991) has also been conducted by ICARDA. Overwhelrmngly the world's largest producer of faba beam Is China. Considerable research eirorl IS d~rected to the uop within that country (see Saxena di \Ve~gund, 1993) and tn collaboration w ~ t h ICARDA (e g IC.ARDA, 19951

3.19 Common bean Common bean (Phnseoltis iiiilgnr:~) is a Sew Worid crop arrsing from mult~ple domesticat~ons o i wild ancestors (Debouck. 1991, Gepts & Debouck, 1991) Approximately half of the world's producnon of I S million tons 1s m Asha, China beine a mator oroducer iF.40. 19951. In the Americas. ma or prw"ucers ;reb0rar.! :he L S a x \lek.co Tne crop n3, at:aines rralor .rrpor:an:e :n i.os:,:e-ce agr.:u.ture and f w d security in Africa, for e\ample In the countries of the East Afncan highlands Although produced mdvrtrlally for processing ie g m the USA), there IS also Interest in the potential of snapbeans in per!-urban agriculture

Tie most serlo-s nema:sde Fe5.l con ro r :ear aye tne :oar-knot nemaroaes. :r partic-.a: !ie spec es $1 n:ognltn anc .ll tn:onlca. m e or born o i nese species pmcatlv affect common bean In most of the tropics o i subhopics (Sikora & Gmo, 1990). Losses of up to W/O have been amibuted to m t - knot nematodes i n err~erimental work conducted both In Kenva INzundo & ?avlor 19711 and Colombia (Mulhn el a1 , fi91a)'~he w ~ d e denetic %artabilrtv present w~thtn the cmp (Stlbernagel cl 01 1991) IS reflected ma w~de range of rer- to rmi-knot nematodes (de Moura k Re@, 1987) with galling in some cases nearlv undetectable and h others revere (ex. Muiim etal., 1991bl.'ln additaon to reduced plant erowth'&ulme from shlnhnz and eallme of the m t s h n m - -

k t - m o t n m & s may lr&enceoacte;al nod~ano; and Increase the tncidence of some d~seases 4.-Hazm.. 1985. France & Abaw~, 1995). Various speckes of leslon nematode (Pntylmchus gpp.) have been found assmated wlth b e a ~ (Sikora & Greco. 1990). During severe ~nfestat~ons, yield losses may reach 10-80% with root-les~on nematodewnd 50-9096 with raot-knot nematodes (de Agudelo. 1980l.The reniform m t o d e , R, m@rm~s damages beans, cawmg M% reciuctim in shaot dry weight in pot experiments and yield mcreascs have followed nemahode control of R, renlformis in field td& (Mbcrley r t nl,, 1981) P iw l i r r vlilgans is a h k t to H, glyctnrs (Melton tt al.. 19851 H~lerodern glycina has been recorded arasitiring beans in Chrna. Japan. USA and Cobmbia (eve 1986; Comez-Tovar 6r hledm. 19%) md m n t l y in Brazil (Famr, prrs.comm.1. The ~ntluence of this nematode on yleid duetion has yet tobe establuhrd. Beuu mav however malntain oo~ulations of H. flyc~nrs In the a b k n of soybeans (~idhli;l et ai., 1981) an2 blamed op rotations need to constder this (51kora & Greco, 19W). Most research on the nematodes of P ni1Snns has bem conducted In the USA. The biology of nenutcdodppbnt relatiomhip has b ~ n lnvestigakd (e.g. Melton d 1.. 1986, Wllcox and L ~ M , 19861 as has nematode control Research on control has larpelv ~nvnt~nated the we of nemat~crdes (e.n. Rhoada. I*; kbawi &?mrier, 1982), but alw the deveiopment of m a h d e wwbnt vanehh (erg \$van d dl.. 1983; Hagedorn

1 Rand. lu&; hnwrga B Rubertr, 192, There L.ir dl*, k n mearch on the Inkgrabon of be.1~ m cmpf Ing ::.:!em and tr,'p rotation, and the influence th~s may haw on plant. paras~tlc nematode ppuiahom (e.g. Rhoades & iarba. 1986, luhmon rt 01. 19Gl Brarli has also conducted :eaea~h on nematodes of Pltasml~~s. In add~tion to survey work (e g. \lachadnMenten r t nl, 1980). biolog~cal stuo.es and 1nr.eshgatlow oidlrease Interactions (..a, Huang L Penira, 19%. Corta.Mamo& Huane 19861 h v e k m don*. Sematode " :ontml neasures irdalea have ncl-cea dse cr :nen!ca:i r g Carva.no re.ti I93! :.lturr methoes le $ jt.arma & 5c~m.a:. I984 am r r s ~ j t ~ n c t screenjnp \atho:r. njtl:utes in lndta ha\.e publuhed research on common bean although most research has been on the more Important I$114 specles, ~n particular mung bean, Vipn rudrlu. Chemtcal control (e.g S~ngh & Reddy. 19811, the use of so11 amendments (e g. Srlvastava k Slngh, 1991). and reststance screening (e g Singh rt a!, 1981) have all beenmnducted. >[any other countries in the world have publ~shed research on beans. Within Africa, after in~tial ~nvestigatlons of pa:hogenicity lr g Ngundo & Taylor, 19741 and vanetal screerung. then hu been no sustained research effort. More recentlv further swey work (e g Assefa. 1987) and nematode c o r b l rhdies 1e.g. Ogallo, 1988) have been published.

The IARC w.tn the *orla mandate for ?hart, .s IS CIAT, aavd at Ca. n Colombia %me mcarc? on be&- nematodes u l s n.t.ated u ~ t n tne la-ncnlng o!:ne Ir.st~.~'e's Field 3eans Pmgralrme :n :973 'CIAT 19741 k-d sore resutance screening was ronlucteo ICl4T 19'81 Sera:sder were 13ennhea as Ir?or!ant patbogens of mandate !orage legumes 3rsmm11tn: s;c . but :t~, war* was a-parently rcr swtamrd Lenne & Stan:or. 159C Stan:on. lj9.t' .A!!nc,:gh more

:ecer.t.v sore co.lacorat.\ e rerenrcn bas bee- ::r.d~cted e g M u m t: 2. :991a k - . no rubs:annve mu:> ~n bean rrmatdes has been cJraLcaa bv CIAT

4. DISCUSSION

4.1 The Institutional Neglect o f Nematology The precmmg xc~ons have dexnkc the mie ?.ant parasiuc nematoaes mav pla) 3s produc:lor constramrr tc most of t-ore crops selected as mar.date crops br. :he I.4RCs I t 1s ev~dent that, with same exceptions, the effort and resources dlrected towards research on plant parasitic nematodes w~tlun the IARCs has been and remalnr much less than even a cor6ervarn.e assessment of thetr s~gm.icarce as .fop PIIS u,ould ment. An exammt.on of A ~ u a ! Re ons &om xrmc se.ectd MRCs F.g 1 shows that as 'The [C s S & - ~ " hu grown and numbers of Senior Screntific Staff &thin these -mtitutes have increased bv 250% over the last twentv vem. numbers of nemato~o~lsis have nma:ned unchangid. at what can onlv oe descrtbed as a ban minimum Although :?ere have been occa~lonal nemacoiogy prolectr at some Centrer only CIP has ever employedmore than one core staff nematologigt and most lARCs have never employed nemtologirts at ail.

Whv has nematolo~v remained so under-reoresented. ~ariicularlv ~n ore~isat~ons which .lace ru ih tmnartance Ln the card!, co&~derat~on and est;bluhmenr of;march pnonnn and goa!s the asxlamert of m a r c h .-rpacn and not least r pmmhng well argued research ~lunhcahom and strategies to donors ?

Fundamentally the general absence of spec~f:c clearly recognwble and ambutable above pund symFtom m a k the unambtguous demonstration of nematode damage d ~ f f i d t toachieve. It has been shown that xrme observers m unable to vlsua..y assess nematode caused re--ctkons In crop gmurh of dp tu 5Cg0 thfal. 19851 m d m a t s n a l i ~ l d m h 111 not detect I ,053 of less than 20°. In vteld :aused by nematodes. Even when nematode attack-produces clear symptom these m y be ~ndishnguahabk from those of, for

Ntnaluiu~m! Airrlrndr 199; Cbi 06 Nu j

example. nutnmt deilclenw P l d r i t .. ndt ~!*.avs pms!ble to preen1 drama1.c example, rr nena:.,ar .lamagc to admnatnton. pol~n.-makers I?C aonorr 5 x 5 d t f f 1 ~ 1 ~ ~ apply equally to, and mfluenct the m t mndamenral stages of the omlect cvcle and research Drocesr I t 1s momtsed . . . . . . . . . -. - that fa;mirs h&e little or no Fer;ephon of ~nvtsible pests (e.g. Cauquil & Va~ssavle, 19941 ~ncludtng nematodes 1e.g. Bentley. 1992: Bridge. 1996). Tha mav then result m the best intentzoned of PRA exerases elther overlook~ng or ms-aributing rematode problem (Gold n 01.. 1993).

A scarclty in nematologlcal expertise or lack of awareness of nematode problems may also ~niluence more formal aseumarb. In a recent Pnonh.Lmng eye- a!CP (Collion k Gregory 1993) the "Management of Cyst Sematoda" was ~ncluded (and given a score or zero) In Project Ranking for potato In the Sub-Troplcai Lowland and the Arid and Mediterranean Agm-ecologtcal Zones .As these nematodes are uoloeicallv unsu~ted, and essentiallv absent from the mo.4g:~rco~ogl:al Zone, :.Y. Jerea tne ra-k~ng .s, on nenatologica! gro~nds . sp~r..,;s Ho!ve\et, root.knot nemtodes. \!tlotdq!w spp are :..)deli m o q x e a IS among the most serious nematode pests of rolaniceous cmps (includmg potatas) m the sub.tmpics and rmplcal highlands &bata. 1594). lh exemse t h u resulted m nematodeoab that were essent.allv abser: :r:- certaln rgro-uologtcal z s n e pdtato cyst nemarodes --imtandatl. h g mud a$ urlmportant whereas the .c?o:tance 01 nematode of potent~dllv malor sianificance :mot-knot nematodes) was bbrcurrd by therr beGg subsumed m another pmpa category (Bactenal Wilt PmjRt) [Colhon k Gregow. 1993)

Thrse ?~!flcu.r!es are .nt*g:a :c, a r J are cxnpounded D,. Ice genera. s:ar:.tv oi I ~ I I - e ? rrrra:o.cg:s:~ and ex- nematoiog~sts) wh~ch is then further reflected In a general iack of nematolomcal exuerlence or awareness in the - . ag:!cul:ura. reseam cornnun:, par:lcu:a:.) .n the rrop.cs Luc r: a1 . 1333 The comrnrr tha' 'svsterru for prlorlty

wmng are p m l y weak and +at xn:omng thu w u k n a r was tmperat~ve" .\+h.ton, lr9i :s partt:uiarlv nievant to nematode pearct. The ct:rL.arl!y oi tnu ~ m t l e m har long been recogrum "Bmw th rs are few m m nermtologuu manv nematode problems cerr2.n :o t e dlaposed, so that uoll&-maklne aeenc~es In bath eovemenia i and prtvate ;ectcR are nu; at;.are oi h e neeZ'+o encoLrage expdmton" H a p 1363 Txs statement a a5 reie! ant tmav l

n e years pmedng the s t a ~ l s m e n t ?f me CClAR

Thls leaves nematologtsts w ~ t h the task of cont~nually needmg to draw the attention ot others to the pest potenha1 of nematodes, w ~ t h a11 the susplclon of self-mterest thu mght pmmole

The h t e c , and n many caoer ammcr of my c u u ~ d m n o n of the role of plant paras1t.c rtmatoaes 15 a senoru shortcom~nn. ;nd one that should be recomwd. A lack of knowledge and ylderstandlng al:owr the p&s.b~lly of the mtslnterpretatlon of rsearch f.ra.ngs and also tncreasu the potentla1 for both erroneo.. ana m~sa~rected nwarch act~bit~es. sometimes in areas considered priorittes by the CGIAR A j~mple .llwtrat~on wt.1 suritc; :J whrt e'xrrnt mght nematode pmblems bp cmplbotd mine "yteld gaps" x, often seen between on.btJ!:an and on.farm t r u b or between intensive and extensive cropping system (e.g. k k e r d 4.. 1994)?

4.2 Research in Plank Nematology and Suatunable Agriculture

Then are compelltng arguments for emphaslslng the x m n c e of w r c h on plant-paras~t~c rematodes m m y

tx appmach to ~ p r w e d agncultual pdoduntvtty b t parvltx narwtcdes aMct man) cornponenu of plant p t h and y~eld and as agncultuml pnduct~on In the worldr devclop~ng reglow continues to ~ n c r e ~ v and lntens~ly the lnflrvMeofpLlntnn\atDdaunbcrxpeaedb- Thu

~nC.en<~ *I . ~ l x ) we ,~wt. w .I x t l v re e5.1-t B>.I,PRI~ ..r tne f~ : - re CCI +R Rrrearcr 4zznrra a.. %: nrJ .n tnc m n t Lurrre klara:tun iCCl4R :R3.

Increased crop productton mav come from etthrr, or both. mmsung neld or lncreasvy the land area under cultlvahon. The relatlvbconmbut~on each of thee has nnje rn Increased apcultural p d u c t ~ o n In the dereiopmg world over the last 35 vearr has \ , a n d greatly rv~th qeographic rewon In Asla W'B of the lnaeases m mmai pmd;ction o+,er th; nod her resulted h m maeased yylelds (notably of "Green Evolution" denved nce and \*,heat varietlrj) Bv contrast m Latm Amencs ..... and Amca a n?e Fr0pOrI.m 31 lrcreaxa pa?-c:ton )Coo- 50". nar res':~: ram :nma*d .a?a area mce. :ult.vanon P1rsmpArge:s3n L l'andva.Lor:n. 1594, Tbe xtennal for

t h e components to contnbbte to the future inmiares m food product~on the world will require, are sublects of prewng concern to the de!,elopment cummumy Thm u a w~despnad recognltlon that the past rate of vield Increase? produced m "Green Revolut8on" crops is unfikelv to be sustained (Anon, 1996) and that iuture research to paise the ',yield barrier" ICIMMYT, 1994) or "yleld plateau" (IRRI, 1896) wlil only produce stead? increments in the welds of these major staples. The potential for further expawlon of cropland IS a h hmted. In South .&la, for example, agricultural land is almost totally developed and only 1% of lncrensed production between now and 2010 1s expected to come irom land expanslon [Anon. 1%).

Future increases In crop pmduct~on will thus need to denve largely from agncdtural mtensd~cahon of those areas already under use (Anon 1996) However arnculhlral lntem~f~canon

7 -

can genera!c a *?s.e range o! c?-cerrs, nor east In aggu'.at:rg )e,! ~ r r r c l r r r ~ \'>,ge 1993 T-., appl~es pan:cu.ar.v :o :la?: Farar.tlc ne:a:ode pest. (~wtcn. wlti inme notable excepilons (and In contrdsl to many insect nests) are eenerallv ~ndinenous to the reelom m which thev , . - . - 3c:~r Con(.e:s.on of sna :o :ro??.ng, or src:'enlng of ia.lsws can nrrease or maintaln p.rx paras.tl: nematodn at damapg Ieveb; kvelr that would decline d m g extended fallows (Caveners, 1972; Oebuii. 1979; Prot r l a / . . 1994a). Manvv~ew the build UD of dant oarasttlc nematodes. rather , . , tnan a loss o! ss.! !e:!tl~ty, a$ a ma o: conporent o i tne pnenomenon at i.ck sods" ,Steaer & Bunre: :3M. Fe:ra k F m , : 9 1 The dwelopmen!of dant parar.nc nematode uroblems mav then be viewed as baih a c a b and a svrnotom . . of a lacs of sd>tatra?~I~ty .n a cr:Fptng s)srer Page k Bndge. 1993 An :RRl p.baaation G.pra kOTm.c, li86 proGda both a clear ~liustratlon both i f the phenomenon, and a h of t k sholtconunm of a lack of nematolomcai mput tn assesslnz such oroblek . Descr~bine vleld recline; in ", cont~nuously cropped rice. me a ~ : h o n des:r oe a '1011.

bUOnatm w~th mot m i d ~ r s , predomnt iy m the upper mil layers, fhis "sod-siclurn~"could k nutigated by cm' rotation, or by roil ster~lisation or flwdtng.%r by r e p i m g top roll wlth subsoil. All thew ob5?wahon9 point ovemhelmingly to the involvement of plant parasitic nematode in the phenomenon the authors are only able to describe as "so11 slcknerr". W~th the recopnitlon that the sustainab>l~fv and stab~litv of crov-vieids are maior developmen!a, and m a r c n goas CG~AR. 139! mere r a need to cons der the contnbut~on p.mt parastnc nematode make to yeid decl~ne and the fundamental role there organlr& may play in "shtft~ng" and "slash and bum" agnculture.

ThreffeAsof lome plant parasitic nematodes on plant growth. and hence v~eld. are Iamlv the result of the dlsrution thex - 1

mganum*caw w trw normal pmcnre, of plxnt : a t owth and sod ekpiorat~on for born water 2nd nutner:, I A ~ Y a n d i i iricnaing meanhcffort at mvestigahng mecknism of droueht tolerance In crovs. The develo~ment of druueht rolrran;vaneues 1e g ICR~SAT. 1933) w ~ i h Irrper roo<ng and .mpmved mot arcmtccture a:e :mponant aaracteruria under ~nvtst,pt!on leg bran, CIAT 1985 rlce. IRRI.

1993.1; cowpea. IlTA, 15% thick~ea. ICRlSAT. 1995bi. Plant varaanc nematodes should dea;l\ k ~ncomorated ,Into mi . - ;uch programmer m\e,t!qanng >oth .ne c i u m of drought .uxepllb~Ln and .r dneiopmg an3 n ~ a m g an, oboenm mechawms of drougnt tolerance

Nutnent (in pamnrhr p h ~ h a r u s ) defiaends, a h mulkng from the fallwe of the plant m t smtem toexplore and cvlott the sod adequately can a h k mkor consequences of plant parasthc nematode attack. Add~t~onaiiv it s i e c ~ g n ~ v d that nematode paraslhsm may Influence dl~r:obt~mr nodulatlon and thus nttrogen fixation In legumes (Hussev & Mccuire. 1987; Shanna k Khurana. 19911. Fert~l~tv leveis themelves mav influence the de ree of damage nematodes cause to plants (Balogun & ~a%atola. 1990. S ~ v a ~ n & Prasad. 1991) \V~th lncreastnz concern over both the Konamlr and . .. -

envtronmentaicost of fertilizers (Plnstrup-Anderson & Pandva-Lorch, 1994) and a search for low-fertil~ty tolerant var~ei~es (e.g. Supnhatno rt al.. 1995. CiAT, 1996) there IS a clear relevance to lncorporattng cons~deration of plant parastttc nematodes Into future research programmes. .A recent aspect of concern, mlcm-nutrtent malnutrition, and the effects on human nutrltlon and performance of dtetan. shortages of elements such as ztnc and lion (Graham & Welch. 19961, mav also benefit from nematoloc~cal inaut \ e m : ~ d e P ~ S ~ P J T P b s bbee smom .o d ~ l m GcmrnGors at vartous elements incl;n.ng 2.r: 3r.a .ron 12 p.ants \leiakebernan ct a!. I%-. Haseel r ! 2 . !W

%,,: terrlrtv may also nase mom Am: m~en:es Its wtde:v .w3psed trat the nurcr r conte-I o. tne so:, m partlcdlar -rea and hence ammoma can sane: nes r m x e nematode ~ovulatbons 5url:ng :)911 P.oivr.qnt and H ~ n t 11994 ;.irking in Cdte d'lCo~i~. examined i field trial comparlnn fetilize;Rgimes on nce Xwnbers of mt.knot nemades on piants grown wlth low ierttl~zer were 50 times greater than numbers on plants m w n under com~lete kmlizer It IS clear . - :tat no fu:l mterpretaror J: understhlrg of obsewwr Iant qrowm or ye!d r a p o w m s u h no:* :an k rraae ~1.310-! :nrorp~ratt.-g some cors aeranon oi the poss~b.e effms oi plant para~thc nematodes

The wtdely recopsed eautmce of .n:eractjons with other palhoptu . H m y k I c G d r e 1957 the mt tiown bemg between rot-knoinematoda M c l o d o ~ ~ u spp. and Fusnum wilts a150 demnstrates the n w t t ) . ici neirjtoiogical input In assessing both the inndence and yield losses due to such pathogens and m deveiopmg cultural irrateges, or bmding o r o m a m aeamst them. r 0

Soddweihn olant uamthc m m t o d e are a blohc mnshtumt of the hevlll g&m&nt CeoPraohc dlrtnbuhoruof nematode - . s p a s d~ffer 'Table 2, sogs&tes are w t d a p ~ l d some of locrl~sed occurrence In A!rlca for example, two specln of rwt-knot nematode (Mrlo~dogynr spp.) cur widely, M incognita appearing to predohtnate in hotter soils md M. Qmnlcn in cooler. wetter soils (Wh~tekad, 19691. Wlth a de;eioping emphasls on producing crop varieties with adaptatton to different agm-ecologlcal zones (krageldin, 1994) there ir a consequent need for mult~.iocai evaluation and a consideration of Genotype x Environment (C x El ~nteractiom in breeding programmes (Quin, 19961. Any cumparism of d b v a r p e d o m in diffemt mwonmsrC In particular attempts at evaluating responses to soil cmditions, should consider thc pasrlbie lnnu~la of diffmnt nematode spec!* in thex d~fferent environments. Plant- parasitic nematodes themselves may be vrewed ar a fundamental constituent of the "E" component m any "C" x "E' utteradion evaluated.

4.3 Institutional Potential of Plant Nematology

contr~buting to a "New Gmrn Re\ oiutnm" CGiAR, l9Piai These organtsation, include unlr ersttles and advdnced -arch msbtute (ANSI ot the "developd North" as weli as natlonei research organlsatinns, extension bervlces and n.33 ?On.governmenta J:gJn sa:lons of ccLnrr:r, of the 'aevelops. South-, coliec:~ve.y cons.dena as the Vano?a.

AgncAltura?~searen Sen Im \ARS,

Thts recognition of the complimentarrtv of activittes by a rangeof "playas" to t h e C G W rmssion has direct relevance to nematolog~cai research The range and sco e of research needs In viant nemntoloer comul~ment botE the varmd contnbunbns the d i l r e n t k d dl<erse mstituhuru w i t h the

~ ~ . . -

G:o3al . A g t ~ c ~ I t ~ r a . R e s e a r S > ) I P ~ codid bring toru;n- rereax.' and !he specla. r7.e tne :.ARCS have to pla" .n Its

It is recoenised that aractlces do e ~ i r t that can ruemrrhllv ........ .~ ~ .......-. manage Flant parar.;.c r.enat=des ano achieve suPtllnab{e crop jrcuLctton even wl!n p a r resource farmers 'Bndge. 1% 'dnne: mearcb a near6 n aeveiopmg and auesslrq nematode management strategies ~ u c h a; c 6 p rotations o i ~mproved fallow;, to m i ~ n u s i losses in diffeient crops and cropping system. These activities fail w ~ t h n the "adaptive m e a h cyde" of tk 'Ydcaltud mearch paradigm" dcrcrihd bv Coilinson & Toilens (19911 and are idealiv suited to the ciose partnershi s existing between [ARCS akd NARS. The activina of IcR~$AT. and more recentlv IRRI. m collabaratinr -. - - . . . - Ir tne :anduct of nernatoce s ~ n e \ ; a n d asslstmg NARB to pee-r.ze nematode pmr e m are exampla

The plant bmdlng ntcessarv to develop new vanettes u the major part of IARC actlvttles in crop reserrch (Fig 1) In the past the most sutamed comnutment to nematology research wi th~n the [ARCS has been that of CIP where a major contrtbutlon was made to developtng potato varieties reststant to cyst nematodes (Globodrra ~ p p ) Jatala and Mendora (1978) have drawn attentron to the long term research Investment needed in this work, success being acheved m clme mliaboranon wtth Amencan and Eum~ean mshhites freptotu where the m o and the wr t achcve &.,or r.gruh:ann?~&ugh rome ofihe . h n d & ~ ~ ~ i k t & d nere ndy be d e s n ~ b d as ' omnan commodtnn' (Piatau & Coihrson, 19921 others are \:re potato, of .mporunce m the r culture of many countries of the "dweiopd North". ~ tgnicant nematoldcal r c m h , in particular in the United States, has been mndicted on vlme of t h m p s . Soybem are a particular example, but also groundnuts, sweet potato and beans h v e all been m\eshnated. Othm munlria, notabiv Australla and India, have made simiflcant contributions t; strateac research on nematodca di cereals. notabiv wheat. In ;ors.aer!ng the real need for strate tc research on the orpha? commod.tln the CCIAR ~ A l i ~ s w ~ r n thelr eco.

repnal strudum and perspcchvcs, have clear advantages.

The potenhal for "spill-over effects" to smallholders of a current m a r c h programme (a programme that involves IlTA on an expoit c~mmodify ;roc bananas, has recently been highltgnted Per5.e) 199rial The ap Itcanon of "on the she f " ruearch ftndtngs Co:.tnxln & !o.lens. 1994) m nomatology from the "aere.oped Sorth" and 1s adaptahon by t w IARCs to the n m of me "drvelopmg So-th" could have s~gn~ftcant Impact tn p.ant nematology Th.1 has pamrJar relrvanm m the app.lcanon of btotechology (iwdf of malor potential .n dcve:oplng counmes Cohen. 19941 to the dnr.opmcnt of nemaroae revorant varlctles ,k Warle, 1993: De ~ a e l e . 19961. Root-knot nematode resistance ir available In man crop cult~vars (Sasser & K~rkby, 1979; Hadweguda &L, 1982, L r h m k c a h r a n , 1991) and the mcorpo-abon of thu rautance, for example by tnrufer of the MI g m (Aartl, 1993), rnto Mandate Cmp vanetie would

As part of a m t l y bhgated p-sof renewal the CCUR be a advance Compand to the era dhxnbed by jahla a a m i n g both its place as an "actor" withln a "Global k Mendoza (1978), the application of such "on the shelf" Agnculhrral System" and the w w oi I& miationship with techlqun to the considerable research effort on nematode &-ti-& of & a Cbbal System (SFngeldtn 199il. resistance screening alreadv conducted on many Mandate Sum n Clokal- ,smidered to embrace a w b k mge Crops ha the potential toc'otuiderab~~ reduce theximfific - -- . - - -- - . - of research ani>i"dddm&t organ~sationa capable of- invahnent d e d in such wort

There are also potentla1 "spl lo l er effects- c,i [RCs using other more applied aspect, oi plant nematolup such as cmp mtatbons, o r cultural practices, dereluped elsewhere (e.g. Dunn. 1987. M c b r l e y k Callaher. 1995, The [ARCS are I n a untque poshton tu ~ t a b l ~ s h the ~mt~ tu t tona l and mearch I~nkages that can. In collaboratton with NARS collabaraton. enable such znheicntly applied research to be adapted to the needs and conditions of smallholders tn the developing countries.

i n much basic research there IS a clear complimentarity between the often regtonai nature of manv nematode problems and the tncreaslnnlv ren~onal focus of IARC act>\ t t m T h e n Is great Farent:a.for ?~~.:.nz w i th SARS co-nlerparts and :o.lacoratorr 13 le\;.dp such research Mar!. develop~ng coLntrtes not,e\e: nave few piant nenublogurs. ma !hose F m n r n a y x hr;nolung m re.anve w k n o n The MCI :o-I plav r s.g~c:an! role born s. capablltty b d h g ' m a In ennula-.g anc :-ord.na~ tne act, I I I~ of nematoloptca' mearch L- !he, counmes ft shou!d be emphaslxd tpat nx- nema:o:oe ca. m a r c h , be ;r I n a r In!ernatlonal Cen!re :r \ a t l ~ n d . ?:?gramme :m be acmmpbhcd klin h m fa.llner R e :zDlta. tnvestment necessary to establish, or enhance, n e m a t ~ l b ~ ~ c a l capanty need not be p a t .

As the concept of a Globa: A p n . r x a , j r s t e r . a m hold the !ARCS are estabLtung neu zseaxn s6uctu:er to opttrmse the contrtbut~ons of various 'players" an the system Such sbuctura mclude "Nehvorh ' of xtenhso c w w n M e on a partrcular prcblem and ' 'Cowma ' of Imhtutffrenten$ into more formal coilaboratl\e arrangements The potent~al conmbuhon of research capab~hty &d experh%e a;allable m ARls of the "developed Sorth" has long been recognised, for example by CIP i n its work on potato. Thts has been formaltsed as the concept of "Shuttle Research" involving close collaboration between IRRI and exDertlse In ARls Bomarao. 1993. I N , !F95:, The pore-ttal rcr tne c . m :c-

ord t~a tcvn of peoprapnlca 1% and .ns!~t~t~onal :v separate mearch p u p ; v i e m a i l a i d the Internet has wen lead to theconcept of 'VWl lntemhonai Cmtfes" (Perslly, 19%b).

Fundamental to an): and all a:ter?ts at r.crearng the effort and resources devoted lo la>! nemarnlog\. :o s appmpnate level ov h e CGIAR IS the conttr l m n neea for a ruomrmuon and awareness of the era:e?ce and potenzal rlqniftcance of plant parastt~c nematodes as CIJV PIS T h s IS a n n a l l v rho same-problem articulated by Hague nearly 30 years ago IHacue. 19691. That such a recvtn~t ion and awareness are bot{lackmg and are needed a leen at some >f .ne htghest levels By wav d e u m p e dunng mc 19% CGUR Wid-Tmn U m n g h e aCdMty 'Plant pmtecnon md p n t rmrugefM7t" was defined ar lurured to d w a ~ s mut pets and weeds" wtth w mmoon of p h t paraslnc n c m t c d a CGLAR 19%

Nemto loghb , i n particular those involved in developing muntnn. must continue to emohas- both the potential importance of plant nematodA, as well as k:gr.ighting the posslble fallmm of rsnonng nematodes A5 :b papar h u b t t e m ~ t e d to aemonstratr ail involved i n aartculture i n develAplng countrtes, not only rerearchers. b u t equally admtntstnton, dens~on-maken and poltcv-maken should recwnuc the vosrtble Influence of plant nematodes on m<product~bn, and tne contr.but;on mrar:h effort on these pesrs can make 12 the development ot rne more tntenstve. vet sutatnable. ~gr:cul ture the tror!d IS going

REFERENCES A u b I ( 1 m ) Aad phOlphMml'. a molecullr mr rb r nghUy

I;& w mot .b t m n a t d r mtroncc i n lomato. Ph.D. h s . pp.141. Wagmingm Agnmltuol Unnenlt!: The N&rbndI.

\bawl. G S.: Cmzar. D C rluxZi Ettacacy ut ovamll and aidlcr* agalmt the lrsum nrmr td r on beans. IQX2 F i o ~ g : c ~ ~ i r ,,nil .Vm:io~ir T.sa 39. 88

. \ d s ~ y a n . ~ o . . ~ ~ t h ! n n . R .\, Ailen18l, b10 (IVTjI. Ecunom~r 10% caused bv the yam nrmutrdr. Suutrllono!~a rrndy. ~n Ntgrrta Plan1 Dlrcltx Rq*lr:rr 39. 471480

Adslyan, 5.0.. Cdlhlnn. R.4 lIY7Yl Rmcknot nematodes ar pests ot yams m wuthrm Nlgem. Nm~a:olo$ica 24,132-134

AioLm~. S 0: Fawolr, B (191). Eflrct o i Pru!yle~cI~uj in,herjrtr Fortuner (1973 an gmwth and vteld d Zm n u l ~ FI FARL.7 under conthnueur crnpptng. Plat11 nnd 5al 138. 133-138.

Ahmrd. S. Sutmudd~n. (1988). Effect a1 mot.bot nematode on chrkpea ~n n l r t ~ ~ ) n to ape o i plant. Ns~ttonnl Aeodm~y ofSc!mcr 1,,,m ,, ?%-U,l

Al-Hnml. AS; lbrbhlk. A.AXI: AWUI.R.;~C.AT 11994) Ckcurnnm, morpholosy and npmductio: of ~ctemdtm alrmr on wheat and barley ~n Saudi Arabta. Pnhlon louml of fimulobyy 12 117-129

411, M.A.; Trabulis. I Y Abd.Elwmea. M E. (19811. Anta nut!< lnnractlon betwe; hlciuldrgynr incoyntta and Ritt:oRnua Irgurnlrluwnml on <owpea Plnnl Dtrnu 66 432-05.

Anderson. 5. (19%) Oat cp t nematode. often overlooked prraslte $n cereals. Wnbta!lj.Arrbht 1976. 7-9.

Anon (19%). Appomtmenu and New Stall Memkn. Mm,ha 6,22 Anon (15961. Fwd and Agncultun. In: World Resources 199697.

A Cu~dr lo :hr Glob1 Ent~~mnmmt (Ed.-wChief, Roberts, L.1 pp. 225-246. WRI and OUP, Washlnglon D.C, and Oxford.

Anwar. S.A.. Chrudry G.Q : Chaudy, N.A. (1973). Nrrnatcda rrraiated wth com and sorghum. Ioumrl o,lA~ncullurnl Rmrh P"")ab 11. 101-102.

Arayampant, L.. Panpltpat. R., PuIHN!. N. (1986). Reachon of ncr vanetles to m t nrmatcde Hmrhmantclln rpp In the field. lntmalenrl Riir RIIM~C~I Nn~t l t l t r r 11, 14-15.

Assell, H. (19871 Hancal bean d t a e n and thesr tmponanp In Ethlopu. Etluqun Idumn! ql Ajrlcu1:unl Scancn 9,5546,

Badra. T, Cavcnas. F.E. 119831. Eflecls of dosage lequencc on tha efleaw of nonluml~ant nemniodea. ~lantam valds, and nemn66e searordl huctuattom a mfiucncd by ramfall, lournal oJ,Vmutalogy IS, 496502.

Badra, T; Elgmdl. D.M. (19791. Slngle and double combltullom of nenut~c~der againrt Rotybnciiulu~ nntfinnlr and Tyknchulul Kmlpnrlrnnr mfutlng cowpea and c t tw . RNur dt NhMtobgk 9 ,L?, --,

Badra. T.: Sleele. WM.; Caveness. F,E. (1980). The employment of I non.hm6gant ncmatmdr for cuntml of rnol.knot md l u b n nematcdrr on yams and crop pmwatzon m storage Nnnlropua 10, 81-65

Baldwm, J.C , Bdrker, K.R. (1970) Host rultabllttv of seluted hybndr, vanettes and ~nbreds of com lo P o i ~ b l l o ~ of Mt lodo~nr ~ p p . bvrnri of Ntmlalogy 2, 345.30.

hiokur. 05.; Babalola. J 0 (19Wl. Palhogerunry of Melodope t~~gn l l i r a Condonu olrlonur. NmLOlqu n r d i l m I& 22-25.

Bauprd. P;Chabner.C.. Martmy. 8.. Meunar, L.; PariaeL. A,; Srr, E. (1989). Comparilon of m e n wmahnda and ~ t u d i a en the vv ol dlbmmahlompmpne In gmundnut ~ I h m in the Sahelun m a of Sumpi. Rrvvrdr NhMtobgk 12,293-299.

k h 4 M.: Helndr~chs, E.; J o h m . 0. (1994). Efiect of cmpplng manstficatton on corutraints in upland rice. WARDA Annual R q o r : 1994. pp. 27-30. WARDA. BowL(, Cbte d'luoire.

kntley. J.W, (19921 Altermtlvn lo p t e l d n m cmtnl Amtcic8: Appl ld studln of local knowledp. Cullurr b Ajncultvn44 10-13.

&mad. T.T; H w m . 5.1.. Saddtql. Z.A. (19%). Rnponv of l$mm knlsl vanctbra (Lnl cubmm Mr.) againrt Mlo~dogyne ~ncwntlr. C u m 1 Nmralolosy 1, i94.

k m r d o . FA. (19931. The challenge of feeding I W millton mi% pcapk wcry year. In: 1n:tmtionrrl Commdity DCYIf~pmml Stmlgw. (Ed. by Hartmtyo. 8.; Smit, H.), pp. 261-275. W V ~ v m ~ l y Pm#, Amtcrdam.

Bhatn. 0s.: DabI. M.R; hh lbn . 1. (19811. Ert~mation of Lou m whut veld due lo thc cenal.cyxt nematode H e m d m mw. Trqtml Pal M a ~ g n n t 27,375.378.

Brenmn, 8 . : Murray C.M. (1988). AVrlNltan wheal dis~asw. ~ r ~ r . - - " . - A&., ,,.-, C""", ,L,F

Bndgr,]. (1982). Nmwt&a M I , J.: Lyong, S.K.1, pp.:

Bridge, J. (198). Pknt-parsrllic nematode pmblms In thc Pnbfk t W r . Idurndl of Nenutnluyy 20, I7LIW.

I. 1. (19931 Wur ldmledumbuhi~n of the mpr m a l o d e p n r t t c r o i bananas and plmtams. In B:::>jtcnf u d Innpnrtd Cpntml of H g l h d &Innnit PSIS illl,l D.e.2:is :n Pwmltnyr dr k c 1 1 Cardinfdt~~a .Mce!:.:i Curonou. 12.14 D a n t k r 1991 (Ed by Cold, C.5. Cemm!!~~.) . pp 18i-1% InA , lbrdan, Nlgerw.

dge. 1. (19961 %ematode management m sujla~nrble and subs~tence rgnrulhtn. .Annul k:.trru of ?Jyrupltlwlogy 34, 201-225

&lriuc. >I. ~ ~ o w n g h t . .A (1~4 ) ) Scmatde parasitu 01 nm. In. Plant h m i ~ a c N m t & m Subtnrptcnl i r : i Tmpcnl .4yncultm (Ed. by Luc Y . Stkan. R A,. Bndge. 1 I, pp 69-108 C.A.0 Inlewttonal, Wallmpiord. CK.

dpc. I.: Mm-Sapt .W. Naniaganda, I (1951 & mnrolhot

born; endopa&it~c nematodk of gmundnuntmm no-%& S ~ g r n ~ Nnuttaloy~m 23, 25L259

:a, I A. de; AntoNo. H . (19891 Scmnlng maze p n o l y p r for nautann to iMtlo~doy/nt ~innnrrn ,\neto!spco B w ~ i t r n 13, 129-137

dhe. B 8. (19841. Nematode prmrhcr of potato. In Pinnl and lnxcl N<matu&. [Ed. by Sickle. \%'.(IRI, pp la:-212. M a m l Dckker Lnc. New York and Base1

d t . 0 B (19951 The orcurrence old samnd parhotpe 01 potato cyst nematode in S s v York ioumni ?fNnatolpgy 27. 491 1Abrm.l

dlr. 0.0.; Ev~N, K., Franc4 ] (1993). Nematode p a r a l m of potatar. In. Phnt R m n t ~ r .Vmutcdn In Trmprrntr Agnoclturr. (Ed. by Evanr. K. Tmdglll. D L. k Webrter. I . . . . ) pp 87-132. Wallmgford. CAB lnterndt~onal wn RH. 11981). Contml rrrateps m law.vaiur c q s In. Pnnoplsad RMurofNmultd~ CDntml ~n Cmpr. (Ed. by Brown. RH., Keny, B,R), pp XI-j67 Aodemlc Pmr, London.

idenhagen, 1.W (1W3). Whence and wh~ther banana -arch ana Ja!e.opmenr ' !* B.:rr:,tno 3~ 4;r .::. ?nr +r Bonono on1 P m ~ . n .a7r>:mrr pp ::-:a L\IB.IP \ :x tpe .lrr Frmce

Ta.0: I \I ? e r a 2 5 C d r x ~ a 4 A 3nmgr l 0 D 19811 Treatmen: 01 .'?.sul.i, :.. iw:, *a, *.ln :\dm\l J.uotvM m acetone or ethanol for thr"cantro1 of phvtonem~oda Rrvvta Cncr 28, W-587.

. , .tlllo, M.B., Arreo, M.B. Lltslnget I.*. 1197;) Population dynam~cr of plant paraihc nematcdu. I. Rulylncl~uiur nn@rmlr 10 a pwr l y dratned rod and Its eiirct on ymld of Aeld legume. Phtlpptnt Agncullunfrrt 61, 238-252.

rbel, G.; Leclercq. D. (19891 Evaluat~on of nslshnce lo the gant race of D!$irnchur dipract by symptoms on fteld kuu (Vrcsfnh L I Nmtologud 31, 216-224.

iquil. J ; Vasraym. M. (199.1). IPM 1n cotton tn S u b h h m n Fmnrh-speaking A h r n In: IPM lmplmun!nt:on Workhopfar Eer~/Cm~rnl/Suutlm AJrjca IVorksl!q Pmccd~np, Hann. Z~mhbw. 1993 pp, 72-82., U\lationrl Reraurca Inst~Otr, Chathun, U.K.

tenlu, F,E (19Tl). Changes m plant prraslhc nematode p o p u l r t l o ~ on newly cleared land Nmntropta 2 1-2 i-. F.E. (1975). Scmnmg cowpea gempl l rm for rrrutwr to m t . h o l nematode at ilU. Nnatroplcn 5, 21.

!-I. F.E (1981). Rool.knot nemaloder on cauava. In P r d ~ n p of tk Tkrd Ilrrarch a d Plnnnlng "4rtting on ba t - K w l Nmmlda. M e b d o g p q ~ . R&nr n/ ild V . pp. 182-188. UNC 5 u h C n p h m Fala h NC ~mns, EE. 11987) N & n a l c k i n soyakan plot tdenhfird. y ~ d d law sseud. lfrA k r r h BnrEj I, 4. ma, FE: Badra, T ( I W ) . Contml of Htl~cotylmchw mult,anctu and Melotdofynr jrwnlcn m ntabl'ichcd planum and nernimdc sunrival as mfluennd bv ramfall. N m l m u n la 10-14 IAR 11991) Second Rmuw of tlu CGlAR pp 194 CClAR Washrngtrn MR (19%) Declaration and 4Rmn Plan The Lucerne Dechabon CClAR N m 2 8-9

LAR 119961 Amvltlcr snd t k h t w In TIv CGUR ...~. ., .... .A.- F m y tk ,&&y Cklimyr m r 1 pp. 1-5 Drummt No. SRO/TAC:IAR/%I6.I C G W W u h u l p DC. IAR (1957a). ( V a m aRlda.l CClAR , V m . 4.14. IAR. (1997b). CClAR H m u r r Su World F m d P n u Lumm. CCIAR N m . 4.13.IL

mdm. S. (1940. Conmbutmnsof tmpxal ml cmp to IDcsemnom~c tmpmvnnmt of the drvebprng world. In: Tmp~ml FLUI Cmpr m a Dmlop~ny Emnumy. P d m p o f l k 9th Sympri~umuf Nr b t m t r d h t t y f o r T m p d Roo1 Cmp,

20.26 &Dhr IY?I .Arm. Glunr (Eli . by Ofon. F.: Hrhn, 5 K.), CIO 149-la3 ISTRT Lh.smam.v.m -" .....,o..,

. . lohamen. C . Hawam. '.I P;%xtna, h P Slrdrr Singh.Sh~mr. S B. Srhrrsat. K L. Burford. I.R., Ru~cld. OP: Kumar Rao. I.VD K Slthanantham. S.. S8n.h F . - , - Ilq8SI Eti-N o i 5011 sala&atton on plbronpea and chickpea. ICRISAT k r r ~ Bul t t~n Nu. l l , pp I6

ChlnnAm. B. Tanb~chttsomktd, N , Tatda. Y (1W51 H c l r ~ d o . :tnt on mrlze In Thrllrnd, brpmw ilrr~~rnal uf Neninuloyy 24.35-3,

CIAT ll9:4) Plan1 Urmatolvgy 111 Cl.4TAnnul R v r r 1974. pp $7 122-124. CIAT C ~ I . Colambia - ~ ~-

CIAT (IYJ) Bran Pmyrum Annual Report In Cl.4TAn1t1ul R p r t 19:: pp 8-1. B85 CIAT, Call, Colombfa

CIAT 119851. Brm drought tolerance Gruing to the mot o i the pmblem. CI.4T.4,8niinl R p r l . 1985 pp 14-15, CIAT, Calt. Coiombl~

c ~ . ~ ~ i i m i . Dccltnin~ inil iertll!ty CIAT r l l Ptrrpcti:r 1995.1996 pp 13-15. CUT, CAI#. Colombta

C141bIYTi19941. CI.iL1IYT ~n 1994 pp. 24 CIMbIM. Lsboa. ,l.r,m ".

CIP (19%). De\elopments an the Contml of Nematode Pests of potam. R p r l uj!J! i :,ld ,Vmrtdde Phtnrny Canfermn. 1978. pp 193. Lima, Pew. CIP

CIP 0988). CIP A!!nuli R p r r I987 210 pp CIP L~ma. Pam. CIP 119891. Annul Rwurt 1989 I78 pp CII: L~ma. Pem. CIP 11992) Annul Rcprt I991 162.60 pp CIP. Llma. Pem CIP (19961. Annul Rqurt 1995 56 pp. CIP Lima, Pem. Clark. C A,. Moyer. I W 1988. Camprndun~ oj iwnt phb dim-

St. Paul. M ~ ~ e r a t a . A B . pp. 74 Clark. C.A.. Wnght. I W. 1983. Eflecl and mproductlon o l

Rotylmchulw rtnliornur on sweetpotato selections, lovmal of Nmatoiofy 15, 197-203.

Coatcr.B~klod. PL.. Brsthwalte. C.WD 11977). Comparison of vunow tntmentr tar the contml of Pmtulrt!cl~ur c o h c In vam Hmolmptco 7, 2046.

cohbn. I 1 (19941 Btolechnolony pnorit~es. p l rnn~nn and pol~cm.

Coil!on, k .~. . P (1~31."Pnorit~ ~ r t t ; n~a t CIP An ind~catce(mmrilorkbr m w r c nll~fltnllon. DD. 55. CIP k ISNAR L~ma k f i e Hague'

Costa-Maruo. ES.. Huang. C.S. (1986). htmcnon kwca Mcbldofytr inrop~ta (race 4) a 4 ndlatn of Rhwtonlp urbnt on Phamfu wI.gam ~ i . kc0 W. FihqlOlop Bmcihlrn 1L W-BM.

Catton. I.. Van &el. H 11993). Qanntme: Pmblems and soiutions. In: Plan! Pnrasillc Ncmalodtr an Ttmprrvlr Agraullun. Evans. K., Tmdgill. DL . & Websar. J.M. (eds) pp. 59-07, Walllnnford, CAB International.

Cauncy, d G . (I%?. Ynn~s. WOpp Longmans, London. Crozol~. PA. k H~drlgo. 5.0. (19921. Respanre of ten cassava

culnran lo the nematode Mtloidugynr tncogntto. Fltptoioga Vtnrirbn# 5, 20-22.

Dahn~ya. M.T.;Akarado. M.O.; A l vaz . M.N. Kahdaneh P.M.; AmbtTummhh. I. O k e 4 I.E.; AUoh, A (1594). Dcvebpment and d w m t a n of appmpha mot m o p pachga to farmm i n Afdo. In. Tmphi h t Cmpr in r Dewloping Emnomy. Pmedinp of lk 9th Sympiwn oftlu l n m t b w l h i (y ,br Tmptrnl Roo1 Cmpr, 20.26 Wbr 1991. A m . Gknn. (Ed, by Ofon. F.; H h t S.K.) pp. 2-9. ISTRC, Wagcnmgm.

Daudi. A.T. ;Wha, D.W,;S~lim,S.N.Kmg.S.B.;Twab.S.(1995). Srreenmg plgeonpea l l n u for mlnmcr to mcl.knol nematodes. In: In,prmmmt ofprgmnpa ~n h s l m a d S o u t h AYm. A n n d Rn;tarr4 Phnnlny Mtelmy. 1994, Natmbi. Kmya. 21.23 5rpt. 1994. (Ed. by Silim. S.N.: Klng.5.8.) pp. 6 0 4 3 . ICRISAT, Paunchem. India.

de A delo F V (19801 Ncmtodn. In, &on pmducnon probimr. (g. by b w a f l z . F. Cu8llenna, EC.) pp. 317-323. CIAT, Cali, Culombu.

b u c k . D. (19911. Sysamaua and @logy In: Common Bmr: PaerrhfaCmp In~pmmml. (Ed by vmSchoonhm. A,; Voyurl, 0.1, pp. 55-118. CAB httmbnrl. Wallingfod UK, m l ~ s a w ~ n with CUT, Cali, Cobmbu.

dc Moura. R M ; k g a , E.bl. (19813. Resprunofkan ( P h o l w uulyaml ~ l t i v a n to parasitam by &bulogynynr ,ownrco and M. mcqn18 (Nemrtoda: Hetemdcndael. Nmurlolqirn Bmrllin. 11. 215225. . . . . . . . ..

&I. L.S.; GupLl, P iIW3). PathDgcntnty of Roykndulur rmrfonnu on arhar Indurn Iouml of Hil l Fnrmlng 6.197-199.

De Warle, D. (199)). Putrntul of h e Tmnrfer for Enginwmg &sauna rgrtnsf N r m t o d a In. B w ~ c l t n o l o ~ Appl~mtronr for

B w n n and PPlontam l m v n r m t pp I l b l 21 . ISIBAP. >lontpll~er.

Dr Waele. D 119%). Fimt Res~,wnrr to Semrtodcs in Other Cr;r Relevant R c u m h l n ~ t m ~ p p l ~ o ~ t m blurt In hi:. :o*l!m In Rhll1nn:t 3mdlmy 5r \r*wtatr. F m n m 14 5.iv.u Ed bv F n m . E Horn. f-P. [k L\arie D , pp :'+:IS LbIBAP %lontal..rr

b Wacie. D : Jones. B.L: 6 l ton. C.: van der kg. E. 11989). D~!~~mcl ius deINo0r In hulk m d veds of pcrnut, ioumf of Sminrtoloyy 21. 14-15,

Dr Hhele. D.. Wilken. R k Ltnderlue. I.%[. ~ IPT l i R c r ~ o n u a1 potato cultlvan to D t t y l m r J r ~ d ~ l r u c f ~ r ~soiated ;mm g m u d n u r &tar Ill smuroluys. 14, 123-126

Dt \',to. \I; b v h r . N.: I ~ e r r a . R.S. (IY801. lntlvence oi hfr:clJujynr ~nmynrln on p i r l h of corn In pots Plar~t D- M, IUk-1026.

L)I iPlto. \I. Valvar. N (1%) D~trr r rnt~vl hatologtral = p o w of Cico trrugum and C nnatnua i m a to hktodrm ocrn S m ~ l ~ l p y i U mnflltmnm 18. 165-167

D! Mto >I.. Gruo, N.; QXCM, h1.C. (1992) Pathogcmclty of Pnr:yknd~u~ IIwmn on ch~ckpea m SF&. Nmlalog. atd!ttrmnra 1,71-73

DI Vtto. M.. Cmo. N., Hallla, H.>l.(.. Mrsbautr. L.. btdt. M.. Benn%ai. S.PS..SU~M. M C . 5mgh. K V.: b l h . h1.B (1%) Krmatodes of cwl-season loud I-n In Sorth Afncr. Sm:oiqffi nudztmonm 22, 2-10

Dt Vito. \I.. G m , N.. Orna, G . h e n * . M.C.. 5mgh. K.B.; Kusmenoglu. I. (19911b). Plrnf pansitc ncmrtodn of Ikgumr In Turkey N m t o i q l a mcd8ttmtnrp 22. 215-251

Doggrtt. H 11988) Sorghum. pp 512. Longrnam Snentlfic m d Techntcal. Hatlow, UK.

Doyle, AD.. McLcod, R.W. Wong, PTW; Hetherington. 5.1.: Southwell, RJ. 11987). Evldence for the mvolvement of the mot lrston ncmatde Pmtyirnchvr lharnn in wheat yleid d ~ l m e m northern New South Wa in Awlmirn Ioumal of Erprrinlrnbl Agnruilun 27. 36Wm.

Chopkin. V H (19891 Intdur:ion lo Phnl Nmatology pp W. John . . . , . . - .. , . . . . . . -, -

Dunn. R:.A. (1987). The Value 01 Crop Rotation for Ncmrtode Control in Florfda. h'cmaloloyy Plant Pmlrrwn Pamtw No 25 pp 1. Coopcrar~vr Ex te~ lon Scrvtce, Galnav~lle, Flonda.

Egunlobi. O.A.: Ola8tan. 1.0 (19861. R a p o w of lU~latdogync lnlected c o m a to some anm.wasle soil amendmmu. Nmalwp~m i6.2243. -

Eeunwb~. O.A.; Akondc, PT; Cavmnr. F,E. 11986). Intenchon " between P~alylmchw urfwnra hlrlodoflgynr jaurnkn md

Lly l rnc l~vlw nnt@mlr m sole and m u 4 cmps of mtu a d cowpea. RNLI at Y h l o l O f r 9. 61-70

Eweruon G . Lundm. P ,1985 &nedme, b r a k S e m n . t n m :ma. o r t MmatMe and P O W O ~ " mlldew rn l se r t oarley vanr:sn Am Hor:,r.r Cmro:n U. 2942.

FA0 [I&) FA^ ~earbdok 19911 Pmduct~on, Val. 48. pp. 243. FAO. Rome.

Faul. >I. Huwzn. 5.1. (1991). Evaluation o l Ientbl culuvrn rgrinrt Ralvitnchlw mfbmrme Ltndford k Olivcira, 1940. N w

~ m [ ~ z - i i & ~ ~ A p , h m i n r r y st& &the dumbulion. orcurnnrr and fluchulwn 01 nce mot mtcda. Ioumsi q Gund A~ i ru l l un r l t l l r g r 5 57-62.

h m n d e r . M.C. (198.988). Evaluation of poum gemp lum (Sahum tukmrum) to lnfeclion by the goldm nematode (Gl6bafrm mlod~unss) m CNk. Nmlmpm. 18.71-74.

km, VR; Ferrir, J.M. (1974). lnlefrebt~onship k h v m nematode .nd plmt mmmuntna m agricullwal umystmu. A p E m y s M L WC-293.

F e y , R.L.; Dub. P.D. 11%). klnnrvpxruthernpea. Haunnu W, 131b1319.

F o m c T,: Memy, G. (1979). Rmt-pralnc n m l c d a o l ria. Rmur dt NtntrM r 5 i9-102.

France. RA.. h w i ? S . (19951. l n t r n n i m h e m fib- i m m # t d a d F w n u m aswvmm lap. p b f 8 on v l c n r d k>r; prep louml oj Nm.* 26 w-174

Fnnco.I.Gnuln.A.hlatm.A. [klp&&laFlor.R(IW11. E f l a ul p m m ndlouun on ~hc s w l v l l o lcv l t m t o d e Ck!&irm ,dl&. F d ~ l o y . 2b. 6F65.

Gwc A.A . Mmd M C .1981) Rclanvr u ~ b l h y o l m e h d - h e a n v a n t a to mfcctml bv mt-knot m m d a

Cqa. P. Debarct D ( IWI) Onpn. domatlcanun and r t ~ o i u t ~ ~ ~ ot the mmmun &an. in Ontttrnn & I N S Rtrmrcitjbr Cmlr i!,~mn:mt (Ed. bvirnSlhunhobm. A.. vuyurt, 0 ), pp 7.g CAB Inlernaten~l \Vallmytord. UK m ussuclatton with CIAT, CJII. Colomb>a.

C rmn l . C (19Mll. PIthogenicih u l the nemrrode SnttNonmm

Dakar Senegal . . , , - ..

Girbr 0. I 19bSi ,-, Inrldmie , - of nemap?e , ptsa of cereal cmps ~n the ". ... ... ?~:!Io~,I!IIoI,,~~ j9,'111-114 '

Goid. C.5. Ogenga-Laugo. >I W.. Turhemeretswe. W. Kasha~ja. I.; Sinhnga. C. (1W31. Fanner Prmpt!om of &tuna Pert

ar.it~~o:ro,~ Matmy ~ l r t o r ~ v i B ~ J H . li-li N&&& 691. (Ed. h i Goid C 5: Cemmtli. B I, p p 3-24. IlTA, lbadm. N p r u .

Goid C S. 5 aqer. PR.. Sch!ll. :: Cauhl. F.: Parbeg.Gru1. C.; Rarrri. $.W (19941 Auesamentr and eharacterurtion 01 and dls~a+r COnstlamb 001 banana m d plantar. Plant hkKt .hl.inrtgmrml Dtarion Anniiai R v r l . 1993 pp. 87-1. IITA. Cotonou. Benin.

Gomrz.Torar. I.. Medlna, C (1983). Hearaim pivc!nes m sovabeans and drv beans m the Caura valiei Colombr. v.h';marronirn l r J~L?;: . - . . . . .. . - , - - . -.

C 3 ~ e - 5 . Q ~ t n t a e n c PC 1999 Vemrtode par2s.m of bananas p.1ntr.r anc aoaca In ? o r : hmr.l,r Y~norsrn tn S ~ ~ t ~ . m l 4, J Tmr .3 ' .A?..* 1.v E l av LLC. M S kufa R A . Bndn 1 pp 431400. ~ A B fnte~auobal,~alltn~iard, 'k.

---. . .. Graham. R D.. Welch, R.hl. (1596) B n r d h Staple Fwd Cm 6 W~th

H~gh ~lxronutnent Rnr l tv pp 79. IF%N Wash on I.C. GWO N.; Brandonw~o. A. (19dk). lnv"1igatl.k on %mdm

;.n.rr 10 Ira.). Ntnmro;f.! m?l.rman&lI, 72.5-143 C m l \' 31 Vtt:, ).I :1986. 1 1 lmponanrr of $ant pataatlc

nrnafocn In lood Iet.mc xoadct8on .:,toe Medltrrrmem regton. in: Nemulodrs>arar~;~ lo Cwralr m d irgums I" Tnpmt r Sm~j*nd rrgronr (Ed, by hxena, M.C.; Sikora. RA.. Snvastava ].PI. Pmcced~n s 01 a Worbhop held 11 L m r c r . C y n u I,; March, 1917, I!ARDA. Syria. p p 2MS.

Grrco, N.. DI %to. M.; Slxena. M.C.. Rcddy. M.V. (1988). Efleci o l H f l d m ncm on yteM of chckpea and lentil a d dwelopmmt of thu nematode In Synr. Nmotobgta H 9 b l l 4 .

Gnliln. G. D (191). Nematode paraszles of alfalfa, cereals, rnd grassn, ln Plant m d lnrrcl Nrnetodn. (Ed. by Nlckle. W.R) pp. 243.321 ,Marcel Dckkcr hc.. New York and Basel.

Cupla. D.C.: Yadav, B S. I19801 Puthqenicity of R~lylenrhulur nntjornt~r on cowpea Nmlo loy r mrdtlmanm 8, 91-93.

Gupta, PC.; O'Toole. J.C. (1986). Uphnd Rlrr. A Clobl P tvdz te . pp. 36Q IN. Los Banos. Phtlltphn.

Had- mndr. W.W.; Suur, 1.N. (1982). Rautancc of tomato, be- wu&m u ard gardm pea culttvln to rcat.l;not nemtodm b u d on !mi su~tabillry W n l D m 66, l&lM.

Hahr, 5.L.; Caflh. L.E. (1982). Contml of plant parasttic ncmabdei on rain sorghum and yk ld m p o w . Fun,$&& nnd Nmt,rtdrknl, 37. 198

~ ~ ......,.. Hagedorn. D I.: Rand, RE. (19%). DNelopmmt and n l e u r of Wu

(>IDRl 117 bean bmdmg hnr. PhyloprNffiiogy 76.10b7-1068. Hague, N.G.>I. (I%9). The tralnlng of plant nrmaldoguw. In:

S m t d n o Tmplml C w . (Ed. by Peachq J.E.), pp. 341-34S Techncal dmmunlcatton No@. Commonwealth Agnolfmral Bureau, St. A l b a ~ . U.K.

Hahn. S.K.; Iroba. I.C.G.; Ikotun, T (19691. Rnirmancr bradlnc in r w t and ntber'crnp at the l n t rmr t l a r l Imtitutraf lk &I AgncYlbn (IITA), Ibadm. Ntgpia. Cmp Pmtrclbn &I%-168.

Hatder, k1.G.: Nath, R.P. (1992). Dbtrlbution of plant parasitic mldn tn MI= ftelds and ~ a w r v l vaht lord o l Hqbkrmur i n d w . C u m 1 Nmlobgy 3,175-177

Hall. b1.R; Johnrcn. A.W. k Smslle. D.A. 1%. Nematode popubtton dynamus and weld of 5wM potato and onion as atfcctd bv nmutictde and tlme of applual~on. Artnab of Apphed ~ i m u a l q y 2. 15-21

h d a . D.K.. Mthur, R.L.: hlathus B.N.; Yadao. B.D. (185). Er tmt lon u l i c n a m barlrv dur to cenrl cyrl nmalcde in wndy a d sandy h m sods Indun kurn~lofNmotaiayylI. 163-I66

Hamunlk. 5.6.. Halrb. H.. Harnb~. LI. (19864 Rcsstam m V i kbr m smn nemahder (Dglmckur iltw::) F.\BIS Nrmrloln 16 17-29

iancen&ttan a h alkalo;b y r l d ;l H&&; iir. .Ve?laloiugm mcd~ lmnm. Ib 127-129

Hashmi. G.: Hashm~. 5.; Kmsbert. L R . Hucttei. R S (1594). Rerlrtance In Zra mnys to Hchmdm :at, lcurnoi ?i ZloMtology 25 HZMZ7 . . , . . . . -

Heald. C 41.: Robwan. A.E 119871 Eileca o i roil soldr~utton on Rotyimduiur rm@nna I" the lather h o Grande Valky of Terar loumni of NtmaloloPv 19. YL103

Hendy, H.H., Cbm;n. A.A. $ngayengr. J 1989a. Nematodes a s ~ l ~ ~ a t e d with vegctabln, fmxt and held cmpr in Buyem. Burundi, Ahca. Bvllrlzn o f fk Farui& A ~ t o l l l u n . Unxuntty of Calm 40, 45-

Hendy, H H. aman . A.A.. Yangavenge. 1 1989b Nematoda a rx rb ted wtth vegetabln. fruit and held cmpr in hbo, Burund~. Africa. Bvilrtln of t k Faculty qi Agnorihn. Untmstty ot Cnlm 40.469-IM.

Zenncy c H :~enntngs 3 L 119851 Carrata Drrcding r Decade or FrOgrCS imm ~ntema:iona. F n g f r m e In .%ym .n Pm: Brta.nt Ea JV RLK ... C E 01 3FI:6 BL :w~o&. Cambridge.

H$llock. Rl.. Sanga, W 11993) Rookknot and other nematodes rrroc~ated wlth ptgeonpea plants lnrrcted with Fuarlvm durn I" Kenya. A,+-Arm loumnl dNm8nloioqy 3, 143-117

Ho lbmk . C.C. Noc. J.P 119W). Lsktmce m .M<lo,dogynr nmmm ul Araclitr rD, and the ~mol~Cat!ON on develoommt 01 mutant peanut culdvan. Psnul ~ C V ~ L I 17.35-24

'

Holl~s. I.?,; Keobmnrueng. S. (19B(I. Nematode parules 01 h. In. Phnl and lnvr l Nmtodrr (Ed bv NcWr, WR.), pp %I&. Marcel k k k m t n c . New ~ o r k h ' h u l .

Hoopcr, D.J (1972). DzgCnckw dlpvcz CIH Dmrplwnr of Pbnt. p m i l i r Nmtodm. St1 I No. 14 CAB. Walhngford. LK. 4 pp.

Haopcr. D.J. (1983). Nematode pesu 01 Vtorpb L In. Tk hh &on WLN l a b L.) (Ed. by Hebblelhwa~te. PD I, pp W7-3m. Buttenvortb. London

Honon. D. ( I W ) . Potatoes: Truly a World Cmp In: Dmloplng World Auncullun, iEd. bv S ~ e t d v A I, PD. 49-53 CrMvmor Press lniemationai, ~ o n d o i . ' "

Huuna. S.P.; Perera. A.C. (1594). Influence o i ulaulun dennly. h i i t and low temperature p n c d on delayed hatch of

i-&i-ii<,-i&~~.R,:~~. WM. A C X I ~ ~ C &. Lor;dm Hymowm, 1. (1970). On the domertlcatfon of the soyakan

Lonomu Bolnny 26 W 1 . bnhun. LK.A.. PakM.A..Ibrah$m, A.A.M. (19M)r). Plant.

p w t t e nematodn as10Coted with g a m m r c w p k n b in northern Egypt. P h t a n Joumnl of Nmatoiogy 6.31-37.

b r a l m . I.K.A., W k . M.A.; Ibrahlm. A A.M. (1%). RabUna 01 barley and wheat cultivan to r m l . h a nrnulcdn. filodqlynr spp. Pntnkan \oumal of ,Vmurlology 6, 3943.

ICARDA (1%). ICARDA Annul W r t , 1994. pp. 1 1 . ICARDh Akppo. Sym.

ICRISAT, (1993). ~ ~ M d t n g the Fmnaen of Dmught Rnurch Annu l &partfor 1992. pp. 37.1. ICRISAT. P a U h , Indu.

ICRISAT. (193%). Dmught-tokrant c h c k p u Annu l M t f m 1994, pp. 22.9. ICRISA'C P1tanrheN. h d u .

ICWAT (1%). ICRISAT Annul W n p r 19%. 79 pp. ICRDAT, Pahtuhtru. Indu.

Igkotu, C.A.: Hmhey, C.H. (1994). C ~ s u v a breeding at C U T hmtabtli ly estimates Md gmetu pmgrnr in th 1 W . In: T m p d Rmt Cmp m a D a d v n t Emnomy. W n g r o/rhr 9th s v m r u m a i t k ~ n t m l m i SWN for. T ~ I h t ~ m . m - ii&& &I. m. G I ~ (a. 61 ~ i o n ; F.. ahn S.K.). pp. I4+l63. ISTRC. M p n t n g m

I l l 4 11W). Mabny r heme tor the wvabwn ~n Alnca. ITTA !n,tunl W r t . 1991 14-16. pp IIT.~. ihrdan . Nt~rrtr.

1174,iWl) A r c $ r h . ~ n pkxiuctton l u r p In Nngeria ITTA Annun! :nun, 1991 pp 11-1; 111.4, Ibadan. h p r u

I1T.i 1:W21 A ??torit il. :T4 Pitbl,cnt!oni. 1?6T.1991 pp. 162. ItTA. badan. Mpru

[ I T !iWl DPcp nm:, m n y brmcher, ihould maker stable Cri-annah tntercrop l K 4 A,!nitni R0mr1199.1 pp 9. Ibedrn. Ntgrrtr '

lnghdm. R.E., blorns LI , Newcomb, C.D ( IR I ) . E f k b o f llrcorporrtlon methtxi or ethopmp and additton o i ald~rarb an pututo tuber tntectlrn by Mdo!odfyrynr Isph. Iolrrnal o/ \mlitlolap,. Zl Its), b W Y 2

I h P !IS954 Guttns to the m t 01 dmught :olerancc In IRRI :?%I995 Walcr .4 .donut~y C ~ ! S S 2 6 , pp. IRN. h M L n o r . Ph>lilplner

IN ,1995b) Partnerrh~p >lakmg the most o i Rnrarch Resources 1,l hbfrr, .4 k w , t ~ t r ~ Sr:,ir iRRi 19PC1995 pp. 4651. IRRI, Lor Banor. Ph~lltp>ner.

IWU :I%). Pmgiam Report lor 1993 pp 289. IRRI. LM Banar, Ph> i l l ~ tnn

Irmatl, A.E.. Hurabo. 5 4 : Abdel.Xlau~h. &!.I (1M1. React~on 01 .sme corn cul t~ran to the cnfectton 01 HritmIvCnckw :,r.ld!gon8c&i i-..n,.on ';..-on. # \v>ro.og, 4. 161- lk

I *~na(a I 1ata.r P :rr:z 3 . C.ctr:r F lFeP Use of FDR 1, ;: .m to t r ~ w f e r re~~,tance 10 mcl..no: rematcd" n t o :.::.rtd i r otat-6% :.mn. c i rnr ln . tr . :?n S~curybr i;..cullrm. kt-!.< 114 :Wb:?l3

l r ~ n R K , Schgal S P 119%) Note on the reaction of lame wheat \anenel lo the cenrl n s l nemaloda lndlan lovmrll of

Jrtala P: Mendom. H fl978l 'k n v n w of the Research Pingramme on the Developmmt d Lsutance to Rwt-Knot lemrtods. Mc!oaly?nr spp. In. Dmiopmrntr m Ihr Conlmi of \rrnalo& PRlr u,ii~olr!u. Rlpurl uf Ik 2nd Nrmalodr Plonn~np i~n j t nn r r , 1978 pp 5W. Lima. CIP

Irruen. H.I.. Amstronq, 1 . lalala, P (1979) Annoldrd Blblio~mphy u iNmlod t PSIS o,iPulao. Lsma, Peru, tnamrtional Potato Centn and Cowall~s. Oregon: Oregon Saw Unlvenlty Agr~rultural Experiment Statbon. pp. 315

lodha. N.S.; Subba-Rao, K.V (1987) Chckpcr World Importance and detfibutlon. in The Chtrtpfa. (Ed by Saxena. M.C.. Slngh. K 8.1, p 1 10 CAB I n a r n l l ~ o n ~ l and ICARDA. Wallingiord, LX, a n 8 A i p b , Syru.

lorattan. E.I.: Pmdlaralan. P (1991). Elbcu of otgane amendmenu In conlmlltng i r e r w t nrmatodn. I n t f n !d lw~ l Rlcr Rtmrrh Nruinnltlln 16. 2, ?5.

Jonathan. E.I.: Velayuthm. 0. 11987). Evrlualton 01 yteld l o u due to rlce root mmatodc Hgnci~mnnndla oymr inlmational N~malology Ntluvrk Vmi i f r ln 1, 4, b 9 .

J o h n . A.W.; Bunon, C.W (1973), Comparvon of mlll*l and rcrghurn-sudan grass hybndr gmwn'h untreated MII and soil treated wllh two nenanc~dn lorma of \nwtolqy I, lU-59

J o h n . A W., Bunon C 1 (1974, hflurnce 01 r v n u n d d n on n m r t m a and varld of ulmhm.sud.nmlu hvbradl and mdleu Pbnt DL& ~rt>61.1012-1617 '

Johnwn 1 T. Dlcksan. D W (1973) Evalurtton of mahods and rates of aml~catlon of t h m mmaticlde . rnuctklda for h a contml o i ih. sting nematode on a m . PIontdingr n f t k 5011 and Cmp S m u 5onr!y offlordo 37,171-173.

lotuuon. A W. h l d e r , C.E.: Glaze, N.C.; Summer. D.R (1983). E l l ~ a 01 intmnve cmpplng system and n t u i d n on nematode popvlat~onr ad crop yhlds. U!DA A~rrcullvml Rnnrrh %mi* Rnuia, ARR.S.14. pp 36.

l o b n . A.W.: Dowltr, C.C.;Glaze. N.C.; Chalbnt, RE.: G o b A M 1992 Nrmrtode numben and cmp v~ r ld In a

s y r m , l o u d of Nrmrtubsy 24.5324% .. -

Jones, F.G.W.; Kmnpon. RA, llP82l. Popuhtton dyum~cr . aaaulation modrb. and mtrsrated contml. h: h t l w I.F.

Endopuuinc nematodes m ~ i l aee mu m WerlemTr.wsviul d l related to mil texture and ramfall. lountd of N n a U q y ZL 35-240.

josh$. PR; Pael. H.R. (1490). Reactlow oigmundnut vanel in to .\lrlduluynr a m r w . intrrnul,owl ,\mkrr NrdrUNI 1, 24-25.

M e m r C. *.. Acwedo. E.: Florer. D , Lyre. K.. One- Monasteno. I.. Byerln. D (19921. \Yhert -rducmn a d gmwcr prrlhccr tn the yaqu! vr l lk i bnira. LIexm. %I Sprial ~ r r So 6 CI\LUYT, L&x. \lexica

klchkcberhan H.. Mbrar.l.hl.. Bnnke. R.C. 3 u n a , I.M.; Cackette. bl. (I987. Eiicct 01 klrluiiyynr :a:.rvr!!n on pbnt nutrient concentnt~on m d la mtlueke on th; p h ~ ~ o l o g y of beans iaurn8ll yf N m m i w 19.32t3M.

Melton. T .a. lacobxn. B I; Nocl. C.R l l9M1 EIIRYS o i temperatun on development or Hrtrmdrn j vonn on Clyohc mar and Plvwolw t~ul fas. lounml ~I,Vmrw!u.u 18, 4 w 7 4 .

blclton, TA.. Sorl. G.R.. larobsen. 0.1.. Haged~ 'rn 3 1 (19851. Comprntwe h a t sultabzlihes of stup h a m to the soybean newtode (Hcto*m jiyclne). Pln8tr Dlrmr 69, 119-122

\leolune. \I : .Abbdd. FA 11993). Importance 31 plant parasltlc nematode aswnrted with wheat and bark, cr.7~1 m MOIOECO ..ll.ilitmm 80, I Z F l W

bl~nton, S..+, Bau~ard, P 119Wi. Senralode paras~te,oipmut. In Planr P~rnrilrc N m t d r r in Sublmp~cal and iwi.tr.l! ,.Lgncultun. (Ed, b? Luc, &I., Sikora. R. A.. Bridge. 1.1, pp. l1L320. C A B Intemattoml. Waliingford, VK.

\lshra. S.D . Gaur. HS. 11989). Readran 01 some chickpea. Crm rnainuni L.. germplarm to the mot.knot nematode Mdo~ddgyv~c ozi~yn!til lntmal~onni Ncmatolop r::mrk Nmsbldr 6. 21-23 ~. - ..

\Icn rma a E. E:gx~a.. A 1 :+a East I .I . : .~ . n :I M ~ D C U cd:tlrarr lo m!.*not nematode '.!r :.o,vrt -.:y:a Bdlo>n >? iw i2: ... !! Ap::.rbrt, LC .cs :, ; j f~.e 11 2.E-213

\!~mnaas f . Paoaxs*arnl \I 5 1% Rcra:a-,rc - swnt potat2 : ~ m m mn,u L lo Vt.?!a?pw n:op :, Kofotd & Whue C h ~ r w w d fin >,aa Icumr :;h: .a, 16, l4&l49

\ I ~ n m o : C 3 Pddhl. V V 1987 at2egen8c er:cl J: n n b r m ncmatxlt a1 \arv.ng rrrr 31 mad.roon 3r p~gronpa 1nrnwi.m~. Smto.ofi Ntrc.< \ci.r.r:m 1 I G l 6

\lor M . C o ~ n E Splege. 'l .:W! P - e n ~ . o p pam~gen.aty and y h o t y p t r of cenai cyst nematodes, ~ e t o d i t a r;.;narab H. atrponj (Semaloda: Heamdendaei ~n brael ,\\iniltolog~ 38, dPd.4nl .,. .-.

\:.!In. B A Aoab. CS ?u:or.Ccna.es \I .\ i ; : r r~ar : L 1:W:a Rwl.vl:l nemalwaasda'm *i:- wara.- Cdombu ana ?err rid n.atebra.d .us Pa-., 3sw'S. 1:%:211

..In. B 4 4oah. C S ?~stor€::ra.er. \t A K:negay. l L 1991~ Rcac!l:nr o i 5e:e:tM brrn p u n I res m: rcctuton,

lo h!t.';.l?r,nr soccla Pmni Dt,uu-j. I?::-I::o rlmanrv ~ y ( 1 9 8 k i Scvhan d l w m l o s esttmatn for southhm united state; In 1984 Pknl Dlwerr 70,393

kamun, 5.. Sano. 2.. Onba. T. An*. M.. NakaMnr. K. (1982).&mrrence of H c f d r m flyrinrr m d lu pathogmrctty to soybean plane m a plain of Kvushu remon. Irpm, Iamnru

nt. b L 3hrl.a .'K 1990~~P~gmnprr Cmra?h . m a hprr tance !* T':r P p n p a El D, Sme. Y L HI:^. S D.. SneOa. V K .. pp 1-1. CAB L-~ernrttonal and IC.UAT, \\altmgtora. L'k and Paulunerr lnau a. YL She~la. VK . Sbrma S B 19% A :ord .st a f r h m

and paqmnpw p r b p pp 2: I C M A T Patmcneu lndu undo. B W . Dylor D.P ,1974,. E l i t c l of .Wbdqpc 4pp on bean vulas m K m v a Punt Duay h r m I 1020-1lV3. , -. . . -. . . .. ., . . . - .

ckcfi,~. (19%). A lolul agttcultural &arch system for the 2151 Fcntuiy In: A e Ciob/mtton d~cMrr: PI^ ~f Ayneultunl h r c h . (Ed. by BontrFndheun. C.. S h e r k h K.1. no. 83-89. ISNAR The Hague.

tto,'~,: iarnga. O.R. (1976) ~ h e i b c a l contml trials of p 0 t a ~ s 1 nematode Hctmdrm ruu. in Nanno: Colombu. SQ!IW F~ top to iogu~ , I, 20-d.'

shm. K.; Makul. 5.; Wauruk. Y (19811. % d m on a m p vquenn m Hokkatdo w t l h s y l e m p ~ u r u on Mavwur a1 agmnomlc chmcCnrt io. I, mwth a d ywld of w y a M lollowing d i l kmr l cmp . k r c h Bul(lh'n u f f k H ~ 1 d 0 Ndtmnal Agricdlvnl E r p n n n l Slalmn No. IM, Il9lP

trton. D C. ( I W l . Ncmalode pansltes of corn. In. Plant ad lnvr t Nmtodr j . (Ed. by Nickle. W RI, pp 61-94, Marcel t kh , Inc., New York ad b 1 .

vauznr E.C.; Fawok 8. (IPSII. Rmt.knot nmrtodes on ylmr m &tern Nigew. in. P W l n g df f lu Thlrd Rnrorch ad Phnnrng Meelmy un Lvt.KMI Krnmtda. Mcloldogya 47.. &glow I V and V pp. 161-167. NC State C s p b . I(r*yh

r. A.P.: Inrem. RN.; O'Bmnun. 1.K; Snto. C5. ( I W i . ' 3 - e 01 Mr** dtirwarl! a d M haph on wheat gmwth l o u d JNcmal04y 16,101-165.

N!yaad. D F: Hrwtsn. G (111). Prcductlon. trade and uxr 1" Lx:dr (Ed bv Wbb. C.. & Hawtln. C ), pp :-!3 CAB Interntomi and IC.+RDA. Wl lu~yk rd , L K md Aleppo, Syra

0 B~nnon. I .H. Ln to GS.; Nycleplr A.P (lVS2: Host rangenf the Columbia m,t-hot nrmaludr (hlcl~tdc~pnr cltc,:uwri>). Plant h e r * 66, IIU>IIUR.

OD1 I lW1. The CGIAR: i k h t Future iur lntemar~onal Agnrulturri Revarch ' Orrrwn, i)nvloy,nml h!rtttttle Bor4ng Pnpr. pp.4

Cpl lo. L.1. 119811. Contmi of nematodesand other lo l l borne pests and d s e a o o i F n n h beans by phmam~phos and cartofutan. .Act# Hdrrtcullurnr 218, 305-310.

Qbult. R.0 t19i9). Shltting culttvvlton dlrmurrges nematodes. tiorid Cmp 31, llilll

Omhega. C 0. Rubens. PA (19921. Inherttance o i nslstmce to ,\kl,udqlogrr spp tn common bean and the genettc bas~r ot ~ t s ~rnnrtllvllg lo temperahrm. Tiwrcflrnl nnd Applld Cmrtdo 83. _-

On%elpve. h l C I., Ogbul!. R . 0 (19911 The reststanre ofeight cutvpca ruit~vdrr IU Llrlotdofynr jninnro. Smmtobgu atd~rrmmm 19. Jib:

Orlon D; Amtr. I.: Krtkun. I. (l9M). Field obrcnattons on Pmrylrncltiu thornel rnd Its effrctr an wheat under arid condtltonr. .it rucnstolay,r 7. 341-345

Prge. S.L.1 11985). i\lr!oadoyynr ilrmnrn C I.H. Cercnpt~onr 01 Plant-pararltac Nemalder Sct 8 , No.ll4. CAB in temr t~on~ l . i ~ l l m ~ l o r d . L' K

Page. S L l ; Bndge. I . 11W3) Plant nematodes and summabill ly In lmplcrl rpncuitun. Expn,mmlal Agnruftun 29, 139-1%.

Pandey, G.; S~ngh. R.0 11990). Effect o i lnorgantc amendmenu on s:.. mtcmflorr anc ?ematode I r m a wi& ,pma, n f r r r n n to :!t J 2 o q ) n r ~nroyn :! an :njcrpra V n A,n~~.r~mlur l, 6 5 7 0

Pans* 3 N w m . 5C I:*! Pcnctnt.on and m~.t:pi~catlon of ccna. F~II nematoce Htt?mrro menat D A ~ ~ J I Y D C 1 tn rellrtani and suxepttblt cu l t~van o ~ b b i l y idin jbu-mi of .V\lmr~lology 11. 172-173

Panhar A.; Yadrv, B.S (1992). Studies on the liir mclc of the m r n rvn nematode. Hmmdrra a r K o ~ h y et rl., 1 9 h on matre (Zra nlayr L l ?~ik~~!n,~ !ilsmiil o/N~nm!oloyy 10, 99-101

Pamtht, I].; Bhrttl, DS (1990). M e a l seed gall nematode, Angufm rr>ficl - a n n t w Citmnl Nnralogy I, 107-136.

Patel. R.G., Patel, D I (1590) Pathogenlctly and biochemical changes ~nduced by nruform nematode. RoQlmchulur n,tlbnnu Llniord and Oilvetra, 1940 in plgwnpea. C u m 1 Vm10bw 1. 11-tl . " 2 ~. ~~

Patel. Y R.; Patel. D. (iP91). Studin on mot-knot nematodn in wheat. Pokunn bumdl o~Ncmatology 9, 119-126.

Pawl. D.J.. Paal. H.V.; Patel. S.K. (19W). bhmatlon 01 avotdrble vald l o u n tn rmenvrrm and cowma due lo rwbknot nematoda. i nb r t 1d;rn.l o f ~ r m i l ~ o l o ~ ~ 20, 219215

Patel B.A.,Cbvda,/.C.. Patel.S.V;PateI, D.1 (1987. Su rcep t~b~ l~ t~ oi some ptgeonpea ltner to m t -kno t nemaloda (.Mrlotdogync ~nco$trlfo and M. ~muin~cn) I n l m b o n r i Plpmnwa ,vnr~dct i i 6s%?

Parley. C.J. (15%a). Gvewtou o i the Banana Improvement Pmlect, In Banana improwmml. molrch chl lmgo and opprtun~tm.(Ed. by Pen*y. G I.. George. PA pp. 21-24. World Bank. Wwhngton. D.C.

Penley. C.I. (1996b). Summary and k o m m c n d a h o ~ . In. BamM Impnnmunt: m z h dullmgcl and opportuntlta.(Ed. b Pmh, CJ.: Gorge. PI, pp. 41-45. World Bank Washington, 6.C.

Ph~ppr. PN.; Batky. I.E.: Lmbnmi. J.L. (1%). Control 01 northern mot !a01 nematode on manut. 1987. funpi& and N m t i a d r B,ts 43.169

Ptnochet, 1 (19881 Commenu on Ihe dllfirulty of bmd ing bananas and plpntam$ for mulance to nematode8 ILVw L ~mn1010gte ~i, 95.

Pimlnrp-Andenon, P. PandyrLoah, (15%). Alleviating P~;rny In t rm~kmg A g n h l N R a d Etfrcttr ely Hanigtng Y a h n l R n o u a n Fxd Apcr l r r v . ond mw nt tmnmmt Jur*u!otl P ~ p r : pp 21 IFPRI. Washmgton. IFPRI.

P h u d KW Calllnran \I P 119921. B t O M M b n and the

~ l o w n ~ h l , k.X; Hunt, D.1. (1%). Plant i a w ~ n c n & i ~ o < - upland, hydmmoqhac and mland swamp ncc ecosystem in Cbte d'lvotn. Afi.&mn loumal o / N m t o l 0 ~ 4 ( , 6147.

Pons. 1.1. da 11987. The nematode9 of m m u and lhar rrnprtanc.. Nmloloy~a Bnudrrm 11, $41.

Prawd, K.S. (1986). Nematode P m b h of Potato. In: Swamp. G. & Dagup!a. D.Rleds1 Phnl P#arlltr Nrmtcdn of Indm. Pmblrnu and Pmgrrr# pp. 351-370. New Dclhl, MRl.

Pewd, IS.; Panwar, h1.5. b. YS. (1987). Nemalode pmblmu of rue tn I d w . T~y l rn i PII~ Uonqtmmt 33, 127-1%.

5ERenmg of elm s p o a mi rhaima n c n o n m lor m w n e

Stkon. R. A. Gruo. N. 1 7 ~ 1 Nemainle p a n s t e of Food Legumes In. Plnnt PnmrIr Nmiin:>,ln in Sublmpml m d Trop~ml.4~ncultun. (Ed by Luc \I sikorr. R.A.. Bndgc. 11. pp 181-233 CAB lntrrnat~onul, iVil lmglod. UK.

S~kora, R.A.: Reckhaur. P. Adrmou. E ,19881 Presence. dutr~button and lrnpnancc of plant.pararite ncmatada a trngamd agncvltural crnpl tn \Iger . i l d r l m ~ m :un dt hrivllri: bn~Ibuu:~:~~utrt~duppn. R!lkun::tri:!n: G n l U, 8214Y.

S~lbrmagel, 11 I.. JaMeM. W. Davs I H C . >lonte de &a. C. (1991). Soap bran pmduct~on In the trnplcr lmpilcnhonr lor genetx improvement. In Conlnwt Benni R~mrrhfor Cmp lnfprovnmr E d by A. \.on %houchoven, A .\byrat. 0). pp 835-862. CAB lntcrmuanal and CIAT, Wallmgford. UK m d Call. Colombta

S~mmonds. N.W l1%61. B~nnnnr 2nd Ed pp. 512. Longmaw. London

S~mmonds, N.W. (19il l. The patentla1 of potatoes ~n the trnptca Tmp~cal Ayncullun. 4. 291-299.

S~ngh, D.B.. Rcddv, P.P 119811. Vote on the chemical contrnl of mt.knot nematodes m inierting Fnnth bean indun lovnull4/ A$r~cultural Scmcs 51, 531-335.

S~ngh, D.B.: Rcddy. PP: L o , VR. !I981i Cu l t~ \ r r$ of French bean resstant to mot-knot nematode, .~l~lu~Aofygyr~r ~ncognrta. m l ndu Tro~rml Pesl ,Uanammt 27. 29-11,

j ngn V D 19% iffcctr 01 nenu:loca sn nrrrat.Me p p ~ h o o n r an= V I P , ~ 51 ;3m 1c.m-l. l; \em.. :,-, 8. ?J2-M3

j nnn V K . L. PK Sank. K P la: Zf!eceot ,fiu.anmu and -%uent~al moculaho~ of Hclemdvn mjmr and Fusnum "durn

rnn .%-Dara.ptr D R I X ? \ ! e r r~ r , rm or res.,tann tn cowpea 13 the m t . ~ n ? t r~n>:.-3e ttt.u-::xd).c in;3fni:a ram I El: r ~ n j ~ c r J n 3 . P?LPI a n . n e a r 2 n : l ! ~ x E C4?. 5 2nd :r,,r?ze":< ,c,a !"2 .? ',.-, . \"J!, c,. 23.3I-bl

thole S Z ~ t 5 t E i198i) Reread chdm$!ne a &"ion to sorghum prntectlon m Zmbabwr 196j186 cmppag ocarcn. Pmrmirnys uf:k nrzrd ky lowi W o r k b p a Soahurn b M~llrlsfn Soullm Afim, pp 165-173 S.AKC!ICRLSAT, Lwka, h b u .

nllh. 0.D; Borwell. T.E.; Tnamer, W H 11978). Lerton nematode muLance n gmundnutr. C 9 Sorncr 18, IWClO l l

5 N (15%). A b m a N of the Lclety 01 Nemalologstr 34th h u r l Meting, LltfIr Rock. Arkmrrs, 5-9 A u y t . 1995. b u m 1 of Nmatology 27, 490-528.

,ulhards, C I., Pnest, M.F (19731 Varlallon m palhogenloty of wvrntecn ~ r o l a t n of Mciotdoyynr tniogoila. Ioumal of Nona lo io~ 5, 6247.

qvustava, A N . %, C.L. (1981). Rehnoruiupr of t ~ t v l ppuhhanr of Hnnodna m wlth plant gmwlh of maw and nrna tde r e p d r r t s m lndan Ioumni ofNmuito& I & 110-114

warlava, A.K . S~ngh, RB. (19911. Use of orgrnlc amendmmu agalnrf Fuwlrrvrn wrlanl and ,\ltluldnfynr ~ncosn!la on Pbmlu r uulgars Nw Agncyflumlrrl L W.

rlvrstavr A.N Seth! C .L (1988). Rnporuc of wrghwn cu1tiv.n to w*hum ;)7t nknnodc. Hettmdm sorghr Indun b u m 1 of Nmrobgy 11, 397-398.

ranton. I. hi. (1%). Nematode d w w . In Dumwr o f l q d pwtumpLrnlr (Ed. by Lenne, 1.M.. T m t m a ~ . P.), pp. 226248 CAB Internattonal, Walhgiord, UK.

tetner G.: B u h r , E.M (1960 Tne plant.nmalode pmblem of the Amertcan Tmplca. loumal oj Aynculturr of lhr Untwnlly d Purrto RtCO, a 69-1W.

rhrlin& G.R. (1991). B~~log&wl Control of Plan1 R n r f I ~ r Nmlcda , pp. 282 CAB Intemrhoral. Wallmgiod. UK

r~nhamo. 5.. Pane. H.: Atdulrachman. 5; Lrkumny. S.. ' ingnm. K'T ( 1 ~ ~ 1 genor)F ~ ~ r c b o n tor 10; fcndtty

dm~ght.prsnt ntnfd IoulmQs In LmnJtd mr'rtu we Aqnrullkra k a ~ ~ ~ f w , l r ~ n - ~ r m:,mnmmrs p~ 4-53 IRRI. I.& B a n a Phtlbplm,

utukt. M (19i9) NW s v m e r i m p mlttvan r e g ~ r t d by w Minrrtryal Apcu lh ln . Fomtrv and Fshena m 1989 Jnpnnr Jvvml u/Bmd,ny 14.

wam B P n v d ] S (1991) Effect of n~trogm f e m k r o n muwnce or ;-tnbdt~ of nc. cultivan to MLrtdogynr -llrr N t w k d q u rmd~rmnm. 19. lE-104

wanon T A Van G d y S D ( I W I C o w mwno to mot- h t t " u w d by h~iodoyynr rnmyngu and M p n w Pbnr Dr*rrw 0 %I-%

Swamp. G.. Gokc, K f I9Sl . Namrlodr dtarrro In wheal, in Phllnt-pw~t~c xeo!atuln of la i~, i :8mblrms art.: :3m\.r.,u (Ed bv Swamp. G.. Dnrjuptr. D.RI. pp 100-311. l n i i l r i Cvunctl ior Agr$rullurii Rrserrrh. New Dr lh~.

Swrwp. G . So,r-lloss. C 11WI \rmutude pair r t l r r o i irreiis. !n ? ! ~ n : Pordsfls ,N\lo~;,~:rdrr I,, S~~br t~ t r~ca l .rnd Twpfrai .4~riad:urr (Ed, bv Lui. &I.: Lkora R A.. Brtdge, J 1, pp IW-13b CAB Internatloorl Wrllingiord. CK

Xhahod. D.. brhosr-Ferrar, L.CC.. di.Ydelho, A R !I9881 Rertaon ot some rovabean culrlr ars to MeloldJfynt ,rwn~co .V~mtoluyta Bnir~lcrm 12. 110-111

Xvlgl. S A : h n o . L I , Anvrr. 5. (lUB:l Populatton bul:d.up 01 phvtonemrtodrs asjoaatd x l t h wal l mtllet 1r~rrn~~t:ionnl ~ r n a b 1 0 , ~ iV~.f:iark ,\c~i,rintrr 4, i s 2 0

Tdd, TC. OaWei TR. (15%) Evaiuat>onof nematiodn for la ion nematode mntrnl ~n corn, 1% Fsqede b Scnmbr7~fr Tslr 30, 198

Lebayashl. Y. Amanu. T. N ~ k a o ~ r h ~ . I. (1971). On the chemlcal i'ontrnl 01 the rlcr wh~te t ~ p nrmdtodr. ApLrlendlo!dtl bnnyr. Chrlslle 1942 BulItl!tt ~J l l t t Atii), Km Aynculrtrml E r y t m m t SIaf!oo 25. I%-70.

Cma &lahawar!. T. Shutma. S.B.. Reddy, D.D.R., Havan, h.1.P. (19951. Cetniection of ,ilrldnlo.prlr ~m-mm and Furnnum oryrporvrn f rp orcn on chlckper Ioumal qfS~nialology iSuwIo~lml1 L:.649433.

and Alenan 4vrir . . - - -r , - , - - \an.G~nds. S D ?cnz B. Sto8zr L i! Thamrson 11 !974. A

p n l management apprnacn re :nr ;.>ntm. > i ?ray ,?:nus :nomtd on *nest 83 ! lc%m I:.-r ~;%rmdro.oq) 6. '--.I,' .",...".

Velaptham, B 1198&11. Inlenrlty of me$trhon of the mst nematcde, Hcl&il~inni on p! conpa m three dstnnr of Tam4 Nadu. Indu Indurn ,ounwi o ~ , ~ m t o i o ~ 18, 383-381

Veinyutham, B I19X8b). Screentng of some plgeonper varieties/l~nrr for reststance to cvrt nematode Hr:tmdrrn cal#fi, lnrtr#a:to,~c~i henmlolof!~ !del!t,ork Vc:vsfel!rr 5, , d 30 ,o-.,

von der Onen.Sackm. A (19921. Fmm iamsnr prevrntlon M rustatnrble derelopmrnt Flnonrr G Dnxlopntml March 1992. 71>0 -"

Waagr. I (1993) blahng IPM Work Developtng County Experience and Prnapecu. In Ayncullun end En~lmnrnmlal C l~ l lmgn Pvaceed>?lgr Jlk Tf~frleenlh Alncullunrl Scnor Spponum.(Ed bv Snvasfava, J P, Alderman, H ), pp. 11%133. Warld Bank. ~arhtngton. D.C

Waiton, D (1%). Rryion.01 Pnonty Srft~ng Rcgarf o,fr Roundlablr. 18-20 Aprt11991 pp 8 ISNAR. Tne Hague.

Walter, A. (19921. Dorr Internattonal gno r l l u ra l Researrh Pay Its h-l r fAT lnlmnllo,mi 11 1-2 - -. - - . . . . . . . . . . . . . . .. . - ., . -.

WARDA 119951. Weit Afifmn Rcr Dli.eiopmml A~roilal!on Annual I(Iporl. 1994 pp 126 WARDA. BouaU. Cbte d'lvoln

Webb, C.; Hawnn. C. (Eds) 11981). Intrcdumon. In imlilr. pp. 1-5. CAB lnlematlonal and ICARDA Wallmgfod LK and Ahppa, sym.

Whttchcad. A.G. (1969). 7'hr dirtnbut~on of mot-hot ncmatodn (Md-2- rp 1 in Troptcd A h a . N m l o l o ~ i ~ 13,31%313.

Whahad . A.C.. me. D.1. (1987). Chemical control of stem nmatoda, D!lylmdw dlpwo, a f r l d b a r u (Wwfak) . Anwh of A p l ~ d B w l w 110, Y1-349

Wllcox. D.A.. Lona. R. (198(1) Water relahow, growth. and yield ~n WOSMD b a n cultlvan mfected wtth ml h a t nematode. 4 l t a l lPpe NIFJ C N t u d l 1et.w. ojik mmOn j r t r r y br Hottn.,;rn j:znrt 3, 24-36

h;tson RE.. Ho.dmcv C 1. Barrakur A 1%31 B m d n r lor mutaw. and tolerance to cereal cyst nematode in w L t . In: Pmcdmgr of tlu Aurlralum Phnl Brndtng On/mnu, Adrhide, 1983. (Ed. by C.1. Drucoll.), pp. 225-227.

Windhm. G.L.: Willtamr. W.P 119881 Rnvtance of maize &reds to hloulogynr incoyncl# and M nrnaru. Phnl Disrnrr 7& 67-69.

Wmslow, RD. iIW8). An ovewtm of thr Important nematode p u of p l a t a r . In Dnriopmmlr tn t k Contml of NmtoAe Pests ofPoblr: Rqwrt uJ1h 2nd Ntmullodt Plrnning bnjevnct. 1978, pp. 16-24, LIM, CIP

Whlow, R.D.; C\'llIt% R.J. 11972). Nematode Dt.raws o i Potato. In Emnontr h'mcaloloyy. (Ed. by Weklrq ].hl.), pp. 1748, Academic Pmr, New York.

Wyatt, I.E.; Fwuliotu, G, Hoffman. J.C., Dcahn. I.R (1983). "NemlSrup" snap bran. HwlSctcncr 18, 7 6 .

Xnu Y L Phi RL LY: Lki, Q.W.: X ~ L P.L un. C.I! OW). 21l MI; MKpod. u (IPPII. R n i ! m ~ w l t h w Eontmb ~ h k u t i D n d ~ ~ ~ ~ p u h g a n n p l a m r s o u r n r C ~ hi&+yttp;enh on m, l e !mmal Uudp . V ~ R C I ~ W Gmnir RsPuna 4,U-U. 4 22-23,

Ymg Y.Q.. Y M & B.1.: Wan& Q.L, (1994). ldcmhtlan of mt.hot P I n g M.W (1W). S ~ d m on the dlxasr mntml of plant mot. nrmmda m IhYy cmpr. /ounuI q'buth Ckm .4gblhin,I bor ncnutcdr (Mdodqpt lupla Chmd). Chrnnc U n m l t y 1$,22-26 Apoclrvnl Snnn Bulkttn I, IS-20

ZAd, F.A.: Bhatti. 0.5. (1986). Control of p mnpe, cyst ncmrro.ie. fitterden upnt K~shy. 196%~ ckrngol 4 treatmenu, India ~ u m l $Nmtoro~y 16,106108 E CAB ~ A T I O N A L M