WEED FLORA AND WEED DISTRIBUTION IN TOMATO

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Tomato is the world’s largest vegetable crop and known as protective food both because of its special nutritive value and also because of its wide spread production.

Tomato is one of the most important vegetable crops cultivated for its fleshy fruits. Tomato is considered as important commercial and dietary vegetable crop.

Botanical name of tomato is Lycopersicon esculemtun and belongs to family Lycopersicae.

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As it is short duration crop and gives high yield, it is important from economic point of view and hence area under its cultivation is increasing day by day.

predominent weed flora in tomato are grasses like Chloris barbata, Cynodon dactylon,Dactyloctenium aegyptium, Echinochloa colona, Panicum repens, Cyperus rotundus, Amaranthus viridis, F. australasica, Parthenium hysterophorus Trianthema protulacastrum., Cleome gynandra.

Grassy weed dominant which account for about 60 per cent followed by broad leaved weeds and sedges.

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Chloris barbata (Syn:Chloris inflate)

Chloris barbata belongs to the family Poaceae and also called as Mayil kondai pul.

It is a tufed. A tufted perennial, commonly found as a weed in dry cultivated fields.

Culms upto 60 cm high. Leaves of 7.5 to 12.5 cm long. Inflorescence with 6 to 15 digitately arranged spikes, spikelets are usually purplish in colour. Fruit is caryopsis. Propagation by seeds.

It is a good fodder grass.

Cynodon dactylon Pers.

In black soils and in dryland is a noxious weed and

once a field is infested with it, cultivation becomes

impossible.

It is considered as one of the ten worst weeds in the

world and problematic in all tropical and

subtropical areas in dry land and garden lands.

It belongs to the family Graminae (Poaceae) and

common name is Bahama Grass, Hariyali. In tamil

it is called as ArugampulluPrevious EndNext

A perennial grass extensively creeping by means of scaly rhizomes or

by strong flat stolons, very common in plains and hills slender and

grows upto 7.5 to 30 cm height.

The underground stems are hard, brittle, thick, pale white in colour

and covered with short scale-leaves and occur at varying depth in

soil. Leaves are linear, finely acute, 7.5 to 12.5 cm long, spikes 3 to

6.

Spikelets are light green or purplish, sessile, laterally compressed,

alternately 2-seriate, imbricate and 1-flowered. Grain is minute,

oblong somewhat flattened, rounded on black.

Propagated by through seeds and underground stolons.

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Dactyloctenium aegyptium (L.)

Dactyloctenium aegyptium (L.) P. Beauv .

is buffalo grass in the family Poaceae.

It is also called as Kakkakalpal in Tamil. It

is an annual, grass growing in waste places

and dry cultivated lands. Stem is Culms

10-62.5 cm high.

Leaves flat, 5 to 20 cm long, glabrous.

Fruit is Caryopsis. Propagation by seeds.

Cattle graze this readily.

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Echinochloa colona (L.) Link.

It is annual grass grows commonly in waterlogged

conditions belonging to the family Gramineae.

It is also called as jungle rice and in tamil it is called as

varnampul. It grows up to a height of 60 cm. Leaf-blade

7.5 to 15 cm long, often blotched with purple or almost

black cross bands ligule 0,2-5(9) cm. Inflorescence linear.

Spiklelets ovoid-ellipsoid, to 2mm with fruit caryopsis.

It is propagated by means of seeds. It is an excellent

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Panicum repens L.

Panicum repens commonly called as Ginger Grass and Inji pillu in tamil. It is a

perennial grass, survive well under moist condition.

Stem is Culms creeping at the base, rhizomatous, 60 to 150 cm long.

Underground stems are thick and hard, very much resembling ginger. Aerial

branches are covered with pointed scale leaves at the base. Inflorescence is

much branched terminal panicle 3-5 inches long. Spikelets is ovoid and

pointed on a short stalk and has four glumes.

Fruit is grain, it is slightly enclosed by the four glume and another structure

opposite to it called palea. Propagation by underground stems and grains. It is

much relished by cattlePrevious EndNext

Cyperus rotundus L

Family is Cyperaceae and common name is Nut Grass, Nutsedge. In

tamil it is called as Korai kizhangu. Stoloniferous, stolons not

bulbiferous, stems trigonous, up to 1 m high, and tubers not zoned.

Stem sparsely tufted. Leaves shorter or longer than stem, narrow,

numerous, bracts usually 3 and up to 60 cm long.

spikelets spreading, linear to lanceolate, up to 2.5 cm long; glumes

imbricate, plicate, pale-brown or chestnut-brown, sometimes with a

reddish tinge; nut trigonous, broadly obovoid, grayish-black.

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• Tubers connected by rhizomes go deep into soil even up to 90 cm and

spread out widely.

• Tubers have a very high capacity for survival under adverse

conditions. Fruit is a broadly obovoid, trigonous, seed-like nut,

grayish black in colour. Propagation by Seeds and nutlets. A very

troublesome perennial weed, occurring in dry cultivated lands,

gardens and in semi irrigated land. It is an obnoxious weed with a very

high propagation potential.

• This is one of the worlds top ten worst weeds.

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Amaranthus viridis Linn.

It is a broad leaved weed and it belongs

to the family Amaranthaceae.

In tamil it is called as Kuppai keerai.

The plant is perennial with long

prostrate or ascending branches and a

woody main stem growing to a height

of 30-60cm. Stem is striate, round and

softly woolly tomatoes.Previous EndNext

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Leaves are simple, alternate, shortly stalked, sub-orbicular or ob-ovate with an obtuse tip.

Flowers are very small, sessile, greenish white, in dense axillary short spikes, which are solitary or clusterd.

The base is tapering.

Propagation is mainly by seeds.

Seed is lenticular, smooth and shining black.

Perianth consists of 5 free oblong sepals, wooly on the back.

The leaves on the side branches are much reduced.

The upper surface of the leaf is pubescent, while the lower one is densely hairy.

It is broad leaved weed and it belongs to the family Asteraceae.

Flaveria trinervia (Sprengel) C. MohrSyn. F. australasica Hook

The leaves at the base of the plant have short stalks while those above are sessile. Blade is 1.5 to 5 cm long.

Leaves are simple, opposite, ex-stipulate and clasping stem.

Stem is round and striate, pale green or slightly tinged with purple.

Erect rigid perfectly glabrous annual herb with numerous forked branches and dense clusters of yellow flowers.

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It is frequently found in loamy soil.

The cluster of yellow flowers in the forks of branches consist of numerous small heads containing either 1-4 tubular bisexual florets with five-toothed corollas or one female flower with a yellow short ray.

The involucre has 2-5 folded bracts and a few linear ones.

The achenes are very small and black with ten distinct ribs and without any pappus.

Propagation is mainly by seed like achenes.

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Parthenium hysterophorus L.

Fruit is called as achene.

Parthenium hysterophorus L. is the generally found in non-cropped situation but now a days a weed of cropped field.

It belongs to the family Compositeae and commonly called as congress weed and visha poondu in Tamil.

It is a annual herb grows upto a height of 1.5 m.

Stem is slunder with hairs, leaves are alternate and sessile flower is white in colour with heads many.

Propagated through seeds.

Trianthema protulacastrum.L. is annual

prostrate herb belongs to the family Aizoceae.

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Trianthema protulacastrum.L.

In tamil it is called as Saranai.

Stem is round, striate, glabrous

below and hairy.

Leaves are oppositve, petioled, petiole

sheathing at the base, obovate, in unequal

pairs.

Fruit is capsule.

Propagation by means of seeds

and cuttings.

It grows gregariously grows

causing considerable hindrance

to normal cultivation.

Flowers is solitary and sessile.

It is broad leaved weed and it belongs to the family Capparidaceae. Common name is Caravelle seed in tamil it is called as Nalla Velai.

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Cleome gynandra L.Its looks like tall, pubescent annual

herb.

Striate covered with hairs.

Leaves 5 foliate, long petioled, leaflets broad – obvoate, acute or obtuse, entire or serrulate.

Flowers pale purplish in corymbs, hypogynous, bisexual, bracteate, bracteolate; sepals 4, free; petals 4, clawed; Capsule cylinderical, nearly glabrous striate,Propagation is mainly by Seeds.

References Gupta, O.P. 1998. Weed management - Principles and Practices. Agro Botanical Publishers,

Bikaner.

Rao, V.S.1994. Principles of Weed Science. Oxford and IBH Publishing Co. Pvt. Ltd., New

Delhi.

Subramanian, S., A.Mohamed Ali and R.Jayakumar. 1997. All about weed control. Kalyani

Publishers, New Delhi.

C. Chinnusamy, N.K. Prabhakaran P. Janaki K. Govindarajan. 2009. Compendium on Weed

Science Research in Tamil Nadu (25 years). AICPR-WC, Department of Agronomy,

TNAU, Coimbatore - 641 003

K. A.A. Kabeer and V.J. Nair. 2009. Flora of Tamil Nadu- Grasses. Botanical Survey of

India, Kolkatta.

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Assessment • 1. ----------- good fodder crops.

Ans: Chloris barbata

• 2. ------------- is a noxious weed.

Ans: Cynodon dactylon

• 3. Dactyloctenium aegyptium propagated by

A . Rhizome b. seeds c. stolon

• 4. ------------ is the worlds top ten worst weed.

Ans : Cyperus rotundus L

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