New instrumentwill aid in detectingseepage from canals

California State University, Fresno

C A L I F O R N I A A G R I C U L T U R A L T E C H N O L O G Y I N S T I T U T E

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In this issue...Labor survey continues .........3

Pruning methods tested........5

The CIMIS connection .........6

Shrimp and rice ...................8SPRI

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taff at the Center for IrrigationTechnology (CIT) have beguna research study to help the

U.S. Bureau of Reclamation reduce theamount of water lost through seepagefrom irrigation canals.

The thousands of miles of canalsthat run throughout California havehelped to make the state the greatestfood-producing area in the world. Yetthe most simple use of this technology –the earthen-banked waterway – permitsseepage into the ground and can resultin considerable loss of irrigation water.

In an effort to reduce excessiveseepage, the bureau, with a $130,000grant, has enlisted CIT’s help in testingthe application of electromagneticinductance (EM) to identify seepagelocations along canals and in reservoirs.

The method employs an electronicinstrument that is placed close to theground surface or just above water. The

See Seepage, Page 7

AScientists seek methods to help soil bacteriaconsume greater amounts of pesticide remnants

Biology student IsraelGutierrez, with guidance

from professor AliceWright, places a test tube

sample of bacteria under asound emitting device

called a sonicator, used tobreak down cell walls.

Diningon 2,4-D

Fresno State professorand several of her stu-dents are using a base-ment biology laboratory

as a center for strategy development inthe battle against soil and groundwaterpollution.

In spite of reductions in chemicaluse by the agricultural industry inrecent years, soil and groundwaterpollution is still a problem in someareas because of the build-up ofchemicals such as 2,4-D (2,4-dichlo-rophenoxyacetic acid) after decades ofpesticide applications.

The good news, reports biologyprofessor Alice Wright,is that soil microorgan-isms are not destroyedby 2,4-D. In fact, someconsume it.

“Bacteria are really cool becausethey take these harmful chemicals andturn them into water and carbondioxide,” she said.

While certain bacteria do metabo-lize 2,4-D, the problem is that thehuge volume used in the United Statesoverwhelms the soil microorganisms,causing pollution of soil and water.

Wright is hopeful that with alittle help, certain bacteria can learnto consume more 2,4-D. Focusing onthe spieces Ralstonia eutrophus,Wright and her team of four studentsare isolating the bacteria, breaking

See Bacteria, Page 2

2 SPRING 2001 UPDATE

Bacteria: Trials will aid in bioremediation strategiesfrom Page 1

down the cell walls and clipping sectionsof genes out of the DNA molecules.

They are using cloning techniquesto replicate sections of genes and observ-ing the response to different stimuli.The hope is to prompt the bacteria torespond to smaller amounts of 2,4-Dmore quickly, and to consume more thanthey normally do.

“We want to improve the way theywork, help them respond faster,” she said.

A “man-made” chemical, 2,4-Dwas introduced in 1944 and is still usedextensively in the United States. Theherbicide selectively acts against broad-leaved weeds, leaving cereals and grassesundamaged and increasing food produc-tion with relatively little labor.

In spite of the known risks of heavy2,4-D use, no scientific studies of this

particular kind have been done, Wrightsaid. And while there’s no guarantee ofsuccess in altering the bacteria’s behav-ior, the effort will provide new informa-tion on the behavior and role of soilbacteria in metabolizing toxic chemicals. “This study will aid in intelligentdecision-making concerning the use of

2,4-D and other pesticidesand may lead to the develop-ment of bioremediationstrategies for pollutants thatpersist in the environment,”she said. In addition to fundingsupport from California State

University Agricultural ResearchInitiative, Wright’s project received$130,000 in special funding from theU.S. Department of Agriculture.

Approximately one more year oflaboratory work will be required beforethe research team can determine resultsof the work.

Graduate student research assistant MireyaMacias places a sample of DNA into aspectrophotometer. The unit uses reflective lightto measure and determine amounts of DNA.

All of the California StateUniversity (CSU) collegesof agriculture have noteda distinct and increasing

demand for CSU’s applied agricul-ture and natural resources researchactivity over the past five years.Unfortunately, the CSU has not hadthe financial resources to completelyaddress this pressing need.

The introduction of the Califor-nia State University AgriculturalResearch Initiative (ARI) in fiscalyear 1999-2000 significantly en-hanced the CSU’s ability to respondto research demands; however,escalating demand for systemresearch activity is twice its capabilityto respond.

CSU Chancellor Charles B. Reedhas recognized the marked increasein demand, the record of ARI success,and the continuing gap between theindustry’s research need and the

CSU’s ability to address that need.Therefore, Chancellor Reed has requesteda $5 million annual increase in StateGeneral Fund funding, above its partner-ship funding commitment, to support theARI.

California has been the leadingagricultural state in the United States forover 50 years. Its agricultural grossproduct value in 1998 was 186 percentthat of Texas, the second leading agricul-tural state in the nation. However, theindustry’s national and internationalpreeminence and a 10-year state eco-nomic boom notwithstanding, theindustry is struggling and is experiencingan economic depression rivaling those ofthe late 1980s and 1930s. As a result, allsectors of the industry and the businessesthat depend on it are in an unprecedentedstate of economic flux and uncertainty.

Driven by the imperative to adapt toits new environment and survive, theindustry is aggressively adopting ad-vanced technology and “best available”management practices developed through

collaborative university-industryresearch partnerships funded by state,industry, and university resources.

The industry and the state’scolleges and universities have beenpartners in education and economicgrowth since the 1870s. The appliedand basic university-based agricul-tural and natural resources researchactivities of the California StateUniversity and University of Califor-nia have played an essential role inthe development of California’sagricultural industry and unquestion-ably have contributed to the state’soverall exponential economic growthand prosperity.

Approval of Chancellor Reed’srequest will ensure that the CSU hasthe resources to (1) respondproactively and progressively to thediverse challenges that inevitably willconfront California’s agriculturalindustry; and (2) assist the industryin balancing agricultural, urban andenvironmental demands.

by Joe Bezerra, DirectorCalifornia Agricultural Technology Institute

CSU chancellor asks state to bolster ARI funding

UPDATE SPRING 2001 3

April symposiumto address labor,employment laws

ew laws affecting labor andemployment in the grapeand wine industries will be

addressed by legal specialists at theupcoming Central Coast WinegrapeLabor and Employment Law Sympo-sium to be held Thursday, April 27in Paso Robles, California.

The half-day program willfeature labor law attorneys MichaelSaqui and Mark Hanna, from theFresno firm Barsamian, Saquiand Moody, presenting “Legaland Practical Do’s and Don’tsof Management: Bullet ProofingYour Operation Against Liability.”

They will discuss legislativeupdates on current labor andemployment laws, employee hand-books, workplace investigations,wage and hour law, and relation-ships with farm labor contractors.

Workers’ compensation issuesalso will be addressed at the sympo-sium. Alethea Leandro-Farr, claimsservice representative with NortonParker Insurance Agency, willpresent “Workers’ Compensation:Effectively Managing the NewChallenges for Employers in 2001.”

In addition, Lori Kammerer,managing director with the Califor-nia Coalition on Workers’ Compen-sation, will speak on “Workers’Compensation: Understanding thePolitics and What We Can ExpectFrom the New Legislature.”

Event sponsors include CATI,the Center for Agricultural Business(CAB); the Paso Robles Vintnersand Grower Association; AgSafe;and Barsamian, Saqui and Moody.

For registration or other infor-mation about the symposium, call(559) 278-4405 or visit the CABweb site at cati.csufresno.edu/cab.

Center for Agricultural Business

Farm worker survey scheduledfor completion this summer

Upcoming events

I

April 24 – Workshop for Trainers ofAgricultural Fieldworkers, in Fresno,California. Presented in English andSpanish. For details, call (559) 278-4405.

April 25 – Workshop for Trainers ofPesticide Handlers and AgriculturalFieldworkers, in Fresno. Presented inEnglish. Call (559) 278-4405.

May 10 – Fourth Annual AgriculturalLabor and Employment Summit: Legal andLegislative Update, at the Harris Ranch,Coalinga, California. Call (559) 278-4405.

May 23 – Supervising for Success: Keys toEffective Supervisory Techniques, at theRichard W. Nutter Agriculture ConferenceCenter in Salinas, California. Presented inEnglish and Spanish. Call (559) 278-4405.

nterview teams from the Centerfor Agricultural Business (CAB)will continue their travels tofarms and fields of the central

San Joaquin Valley this spring andsummer to learn more about working andliving conditions of farm workers.

The teams are obtaining theinformation as part of a labor anddemographics study sponsoredby the California Agricul-tural TechnologyInstitute (CATI).Project directorAndrew Alvarado,professor in the Depart-ment of Social WorkEducation at Fresno State,expects to complete the surveyof 300 farm workers by the end ofthe summer.

A key objective of the project is todetermine how increased interdiction bythe U.S. Border Patrol along the Califor-nia-Mexico border has impacted Califor-nia’s farm work force.

“Media reports suggest that the long-

established illegal entry points intoCalifornia by Mexican and CentralAmerican workers seeking employmentin agriculture have been abandoned forother entry points further east along theborder and into Arizona,” Alvarado said.

Greater risk upon entry would likelyresult in longer stays by immi-

grants, affecting the size ofthe labor force, he explained.

Another aim of thestudy is to deter-

mine effects of thefederal WelfareReform and

Reconciliation Actof 1996.Among the expected

impacts of the act was alarger pool of workers for agri-

cultural jobs. Alvarado hopes todetermine more specifically how

many farm workers were recent recipi-ents under county public assistanceprograms such as Temporary Assistanceto Needy Families (TANF).

“This information would allow usto ascertain whether or not this grouppresents a viable and dependable sourceof labor for agriculture, and if it does,then to what extent are recent immi-grants pressed for finding employment.”

Alvarado’s survey teams aretraveling to locations throughout thecentral San Joaquin Valley, and withthe permission of employers and laborcontractors, are interviewing farmworkers about their working and livingconditions, wages, resident status,health, means of transportation, andexperiences in obtaining employment.

The survey is targeting thoseworking in grapes, citrus, tree fruit,vegetables and cotton.

Surveys of farm labor contractorsand employers also will be conducted to

See Survey, Page 7

N

4 SPRING 2001 UPDATE

Center for Irrigation Technology

T

Spring seminars to address irrigation issues

I

New researcher to aid in soil moisture, dairy studies

rrigation education sponsored bythe Center for Irrigation Tech-nology continues this spring and

summer with workshops addressingpumping and irrigation scheduling.

All three sessions listed belowwill be held at the Southern CaliforniaEdison AgTAC in Tulare, California.Lunch and continental breakfasts willbe provided at the following sessions:

April 26 – Agricultural Pump-ing Stations, from 8:30 a.m. to 1 p.m.,will address the components commonto pump stations and their impact onenergy requirements. Workshop will

he expansion of researchaddressing soil moistureand salinity in California’sSan Joaquin Valley has

resulted in a new scientist joiningthe staff of the Center for IrrigationTechnology (CIT).

Florence Cassel Sharmasarkarbegan work in January focusing on twomajor research efforts overseen by CIT:1) determining the extent of water lostthrough seepage from the thousands ofmiles of San Joaquin Valley aquaducts;and 2) developing laboratory protocolsfor measuring chemicals in dairylagoon water.

The canal seepage project issupported financially by the U.S. Bureauof Reclamation and California’s Depart-ment of Water Resources. It will requireCassel to travel throughout the SanJoaquin Valley, measuring soil moisturecontent along canal banks (see article,Page 1). To determine soil moisture,Cassel will use an electronic device that

creates a magnetic field in the soil andthen measures electrical conductivity.

For the dairy lagoon water project,Cassel will spend most of her time in thelaboratory and at a computer. She isdeveloping lab protocols for measuringlevels of oxygen, acid, and other chemi-cal compounds in the water. The lagoonproject involves the addition of sulfuricacid to make the water more amenableto microorganisms. Increased microbialactivity should help reduce amounts ofsolid material and also reduce unwel-come odors.

Cassel obtained most of her post-secondary education in Europe. She is anative of France and attended a private

New CIT researchscientist FlorenceCassel Sharmasarkarholds an electronicdevice for measuringelectromagnecticinductance (EM) inthe soil. Data willbe used to helpdetermine moisturecontent.

conclude with lunch.May 8 – Basic Irrigation

Schduling, Part 1, from 7:30 to 9 a.m.,will offer information needed for irri-gation scheduling. Continentalbreakfast provided.

June 12 – Basic IrrigationScheduling, Part 2, from 7:30 to 9a.m., will feature use of informationprovided in part 1. Continentalbreakfast provided.

For more information on these andother upcoming workshops, contactTim Jacobsen, CIT education special-ist, at (559) 278-6033.

agricultural school called EcoleSuperieure d’Agriculture in the city ofAngers. Part of her bachelor’s andmaster’s degree programs required herto study abroad. She spent two years inSpain and one year at the University ofWyoming in Laramie doing research andmanagement studies.

After earning her master’s inFrance, she returned to Laramie andcompleted her Ph.D. in soil-waterphysics and agronomy. Both she and herhusband, Shankar, developed connec-tions to the Fresno area through researchassociates. Shankar has a Ph.D. in soilchemistry and is serving as an adjunctfaculty member for Fresno State’sDepartment of Plant Science and isconducting research for the USDA’sAgricultural Research Service based inFresno.

Cassel said one of her major areasof interest is water use efficiency andpollution control.

“I believe water managementpractices are essential for sustainingCalifornia’s agricultural productivityand reducing environmental pollution,”she said.

Support for Cassel’s position isthrough special project funding and is upfor annual renewal. She is part of a CITresearch team that has submitted a majorproposal to the CalFed program formeasuring and monitoring soil salinitythroughout the San Joaquin Valley.

'Study abroad' programled France native to U.S.for soil, water studies

UPDATE SPRING 2001 5

Viticulture and Enology Research Center

Pruning methods tried on Chardonnay vines

Upcoming eventsJune 3June 3June 3June 3June 3 – Annual Celebration of Wine andtasting at Dennes Coombs' Riverbend Ranchin Madera. Funds raised support theVincent E. Petrucci Library. Sponsored byFresno State’s Viticulture Alumni Club. Formore information call (559) 278-7151.

June 27-30June 27-30June 27-30June 27-30June 27-30 – American Society of Enologyand Viticulture Annual Convention in SanDiego. Fresno State Viticulture and EnologyAlumni and Friends Reunion, to be held inconjunction with the event. For details call(559) 278-2089.

Aresearch team from FresnoState’s Viticulture andEnology Research Center(VERC) is monitoring the

performance of Chardonnay grapevinesunder different pruning methods in theSan Joaquin Valley. .

Chardonnay is considered one ofthe finer white wines, and the varietal ismost often grown in regions cooler thanthe San Joaquin Valley, noted researchteam leader Sanliang Gu, who holds theRicchuti Chair of Research at VERC.

However, with the right combinationof rootstock, variety and pruning

explained. An advantage of mechanicalpruning is that work will not be affectedby labor shortages. One advantage ofminimal pruning is lower costs.

Each method can have drawbacks aswell as advantages. For example, handpruning brings higher managementcosts. With minimal pruning there isless control over quality.

Gu said the Chardonnay study pro-vides specific yield and quality informa-tion that growers can consider in theirown management plans.

4.50 for the hand pruning, 4.27 formechanical pruning, and 3.53 forminimal pruning.

Additional details of the study are ina report titled “Effect of Pruning Mecha-nization on Vine Performance and FruitComposition of Chardonnay Grapevinesunder Warm Climate Conditions in theSan Joaquin Valley of California.” Thereport is located in the VERC researchpublications section of the CATI web sitelocated at cati.csufresno.edu.

Funding for this study was providedby CATI and the American VineyardFoundation. Vineyard management wasprovided by Metzler Family Farms. Guis seeking further funding in order toobtain several seasons of yield data forthis project. More information will bemade available as work is completed.

"We're trying to see if we can come up with thebest combination of methods for producingpremier Chardonnay grapes in this region."

technique, growers may find the warmerregions to be suitable as well, Gu noted.

“In this area, it is not certain whatto expect from Chardonnay vines,” hesaid in outlining the study. “We’retrying to see if we can come up withthe best combination of methods forproducing premier Chardonnay grapesin this region.”

The main focus of the study hasbeen on pruning methods, Gu said.Conventional, mechanical and minimaltechniques were employed on vines in aprivate vineyard near Fresno, he said.

The typical advantage of handpruning is a more open canopy, largerberry size and earlier maturity, he

Data from the summer of 2000show the per-acre yield from the handand mechanical pruning treatments tobe nearly identical, at 13.85 and 13.69tons per acre, respectively. The minimalpruning treatment resulted in a higheryield of 15.48 tons per acre. Theminimal pruning treatment was har-vested approximately one month laterthan the conventional treatment becauseof delayed maturity, Gu noted.

Fruit quality measurements weresignificantly affected by pruningtreatment in this study. For example,pH was 3.94 for the hand pruning, 3.53for mechanical pruning, and 4.14 forminimal pruning. Titratible acidity was

VERC research scientist Guoqiang Du displays the threepruning treatments of Chardonnay grapevines in a com-mercial vineyard near Fresno, California. They are, fromleft, hand-pruned, mechanical pruning, and minimal pruning.

6 SPRING 2001 UPDATE

Dec. Jan. Feb.

CaliforniaIrrigationManagementInformationSystemOCT

OBER 1

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Chart shows ETo variation from normal over last three months.

FFFFFor more CIMIS infor more CIMIS infor more CIMIS infor more CIMIS infor more CIMIS informormormormormation...ation...ation...ation...ation...

Northern DistrictEugene Pixley(916) 529-7392pixley@water.ca.gov

Central DistrictMark Rivera(916) 227-7603mrivera@water.ca.gov

San Joaquin DistrictKent Frame(559) 230-3334kframe@water.ca.gov

Southern DistrictSergio Fierro(818) 543-4652sergiof@water.ca.gov

CIMIS information is published quarterly in the CATIUpdate newsletter. Articles are provided by the CaliforniaDepartment of Water Resources, CIMIS program staff.

For more information about CIMIS or its programs,contact any of the following representatives at these offices:

lf you are unable to reach a CIMIS representative nearyou, call the CIMIS Helpline at 1-800-922-4647.

Weekly ETo Comparisons for FresnoWeekly ETo Comparisons for FresnoWeekly ETo Comparisons for FresnoWeekly ETo Comparisons for FresnoWeekly ETo Comparisons for FresnoFresno: 12/01/00– 2/28/01Fresno: 12/01/00– 2/28/01Fresno: 12/01/00– 2/28/01Fresno: 12/01/00– 2/28/01Fresno: 12/01/00– 2/28/01

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CIMIS Station #80CIMIS Station #80CIMIS Station #80CIMIS Station #80CIMIS Station #80Fresno StateFresno StateFresno StateFresno StateFresno State

Energy Conservation: The CIMIS ConnectionFor many years now, the Depart-

ment of Water Resources, local wateragencies and universities have advocatedthe use of CIMIS ETo data to helpincrease water use efficiency throughimproved irrigation management.

Improved irrigation managementresults in a reduction in applied water,an increase in crop yield, an improve-ment in crop quality and landscape, anda decrease in energy use. While severalof these benefits have been documented,decreased energy use has not received alot of attention.

During California’s current energycrisis, however, it is fitting that theimpact of improved irrigation manage-ment on energy conservation be high-lighted. Energy conservation is directlyrelated to a decrease in pumping result-ing from reduction of applied water.

To illustrate the potential for energysavings, a conceptual analysis is pro-vided below. It is based on a statewide

achievable applied water reduction of250,000 acre-feet in agricultural and150,000 acre-feet in landscape pressur-ized irrigation systems.

For analysis purposes, let us calcu-late energy savings based on a singlepumping plant operating at an overallpump efficiency of 65 percent and pres-sure of 60 pounds per square inch (psi).How do we compute energy savings?We can use the following equation:

OPEAFTDH

MWh*000,1

**024.1=

MWh = energy savings resulting from reduction

in applied water

1.024 = multiplication factor (it requires 1.024

kWh to pump 1 AF per foot of pressure)

TDH = total dynamic head (feet) or pressure that

the pump has to overcome (2.31*60 psi)

AF = acre-feet

OPE = overall pump efficiency in fraction.

1,000 = conversion factor from kWh to MWh

In this case, for a 200,000 acre-feetreduction in agriculture and a 150,000acre-feet reduction in landscape, thepotential energy savings would be43,000 MWh in agriculture and 32,000MWh in landscape for a total of 75,000MWh. If this single pumping plantoperates 4,000 hours a year, then totalpower savings would be 19 MW.

As the calculation shows, there is apotential for reducing energy consump-tion by increasing water use efficiency.However, it must be noted that toachieve the kind of savings calculatedabove, other irrigation managementpractices must be used with CIMIS.

These practices include improvingirrigation system uniformity andmaking pumping plant operations moreefficient.

Visit the CIMIS home page at thefollowing address:

wwwdpla.water.ca.gov/cimis.html

UPDATE SPRING 2001 7

Salsa project provides educationfor students, product for public

from Page 1

Seepage: Furthercalibration neededto finalize data

State ZipCity

Name

Company

Mailing Address

(These publications may be viewed in their entirety on CATI's World Wide Web pages,located at cati.csufresno.edu. Single copies are also available by mail at no charge)

Publications availableUpdate:Spring 2001

Ordering Information:Check the publication(s) desiredand mail or fax form to:

CATICalifornia State University, Fresno2910 E. Barstow Ave. M/S OF115Fresno, CA 93740-8009Fax: (559) 278-4849

r A New Tomato-based Salsa: Continued sensory evaluation and shelf-lifestudies of the microbial loads of salsa containing microwaved dehydratedcilantro, by Amy Schauwecker, Hector Ochoa and Dennis A. Ferris. Pub. #000802.

T

Center for Food Science and Nutrition Research

he proliferation of tomato-based salsas in Americangrocery stores reached amilestone recently when

salsa surpassed catsup as the condimentsales leader.

A number of factors influence thetaste and quality of a processed salsaproduct, noted Professor Dennis Ferrisof Fresno State’s Department of FoodScience and Nutrition. Ferris and histeam of student researchers have learned

much after compiling three years ofanalytical and survey data on processingmethods, shelf life and consumeracceptance of salsa prepared in theuniversity’s food processing laboratory.

The purpose of the salsa project wasto develop a salsa using a specially-driedcilantro that would replicate the flavorof fresh cilantro. Researchers ran freshcilantro through the microwave vacuumdehydration process (MIVAC®) at FresnoState and then added the dehydratedcilantro to the salsa mixture late in theprocessing phase.

Consumer surveys were conductedcomparing salsa with the MIVAC-treatedcilantro and salsa with fresh cilantroadded at the same time of processing.

Sensory evaluations revealed that con-sumers preferred the product with thefresh cilantro added over the salsa withthe MIVAC-treated cilantro. Because ofpredictions that the fresh cilantro wouldlose its flavor during processing, theresults were unexpected, Ferris said.

In spite of the evaluation results, thework was significant, Ferris reported.

“Overall, a successful product wasproduced for a target market that likesand purchases the product. Salsa sales at

the California State University, FresnoFarm Market have been substantial andcontinue to grow,” he said. The projectalso gives researchers the opportunity forfurther investigation using other MIVAC-treated herbs and spices, he added.

Details of the final phase of the salsaproject are in the publication, "A NewTomato-based Salsa: Continued sensoryevaluation and shelf-life studies of themicrobial loads of salsa containingmicrowaved dehydrated cilantro."

Funding for the work was providedthrough the Center for Food Science andNutrition Research (CFSNR). Thepublication is available on the CATI website at cati.csufresno.edu/cfsnr. To requesta print copy, see the order form below.

instrument sends an electric currentinto the ground, which induces amagnetic field. The instrument thenreads this induced field. The strengthof the induced field is dependenton several factors, including soilmoisture, soil texture, and soilsalinity.

The EM method allows rapidfield assessment, but the data gener-ated is what is known as “relative”data. Also required are detailed fieldinvestigations using more traditionaltechniques that result in “calibrated”data. These methods combined helpengineers and water managers locatethe potential seepage areas.

Common indicators of seepagealong canals are soil saturation orexcessive vegetation growth alongcanal banks. Other assessmentmethods include actual damming ofcanal sections and measuring waterseepage into the ground.

The study is expected to takeabout one year, reported CIT projectengineer Pete Canessa. Results willbe released through field day presen-tations and other methods.

from Page 3

Survey: Contractors,employers also queried

determine their sense of work forcestability.

Analysis of the results will becompleted later this year, Alvarado said.Findings will be reported to employergroups, to governmental agencies and toothers in California agriculture.

Also supporting the project are theU.S. Department of Labor, the Califor-nia Department of Health and HumanServices, and the California Employ-ment Development Department.

8 SPRING 2001 UPDATE

CALIFORNIA AGRICULTURALTECHNOLOGY INSTITUTE

California State University, Fresno2910 E. Barstow Ave. M/S OF115Fresno, California 93740-8009

Update is published quarterly by the California Agricultural Technology Institute

College of AgriculturalSciences and Technology

California State University, FresnoSpring 2001

CATI Publication #010401

Voice number: (559) 278-2361Fax number: (559) 278-4849

Director of Operations: Joe BezerraPublications Editor: Steve OlsonEditorial Assistant: Mike Rivera

Non Profit OrganzationU.S. PostagePAIDFresno , CAPermit No. 262

Address Service Requested

Biologist tries 'Med fly' approach to control shrimp

When most Californiansthink of shrimp with rice,they probably think of adelicious culinary combi-

nation at a favorite local restaurant.When farmers in central California

think of shrimp with rice, most grit theirteeth, wrinkle their noses, and complainabout loathsome little watery pests.That’s because very small crusta-ceans called tadpole shrimp,invasive to California, havefound their way into grow-ers' water-coveredrice fields, where theydamage the seedlings.

In an effort to solve the too-much-shrimp-with-rice problem in California,a biologist at California State University,Fresno has spent the last year studyingthe effects of a hormone that has beenshown to hinder the reproductive abilityof the tadpole shrimp and may help incontrolling populations in rice fields.

Tadpole shrimp damage rice byknocking over the young plants, orcotyledons, during foraging activitiesbefore the plants have a chance toestablish firm roots, noted ProfessorBrian Tsukimura of Fresno State’sBiology Department. For years growershave used the pesticide copper sulfate tocontrol the shrimp, but that is likely to

change in the near future.“Copper sulfate accumulation in rice

fields has become a significant problemin that the buildup of residues creates lessfavorable growing condition for rice,” hesaid. “Also, there are increasing numbersof reports citing the detrimental effects ofcopper sulfate on game species, and strict

regulation may be soon in coming.”Thus, for rice to continue to be a

viable crop, an alternativemethod of controlling

the tadpole shrimpneeds to be

developed.

The hormoneTsukimura is studying,methyl farnesoate (MF), is pro-duced by more than two dozen crusta-cean species and a number of tropicalplants. Laboratory studies have shownthat when MF is given as a dietarysupplement to the tadpole shrimp, itinhibits egg development. If this methodwere to prove effective in hinderingreproduction, it could provide an “envi-ronmentally friendly” way of controllingshrimp populations without pesticides.

Another portion of the study involves

determining a way to get the shrimp toconsume the MF in the field. Laboratorycontrols allowed student technicians toassemble a specific dietary regime con-taining the extra MF. For field applica-tion, Tsukimura is seeking to develop aMF-carrier material which can beincorporated into feed pellets, which inturn can be broadcast across a wide area.

The tadpole shrimp grows to its fulladult length of three to four centimetersin about 30 days, and can start depositinghundreds of fertilized eggs for successivegenerations after just nine days.

Using a biological control methodfor the tadpole shrimp is similar to thatwhich has been used successfully in

California to control the Medfly. The method “permitsthe existence of adults yet

controls the production ofoffspring,” Tsukimura said.

Initial project funding came fromCalifornia State University’s AgriculturalResearch Initiative, which is adminis-tered by the California AgriculturalTechnology Institute (CATI). Continuingfunding is being sought from the ARI, aswell as from the U.S. Department ofAgriculture and the California RiceGrowers Board.

In the event of incorrect address information or extra copies to your workplace, please return thisaddress label by mail or fax with your requested changes. CATI fax number is (559) 278-4849.