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  Common Weeds in Rice Field

Grasses > Sedges > Broad Leaved Weeds >


Ikisan - Grass Weeds Of Rice

Common weeds in rice fields are grouped into three categories

  • Grasses, Sedges and Broad leaved weeds

Grasses

  • Grasses are the monocots with two ranked leaves, that are usually long, narrow and upright with parallel venation's.
  • Resemble rice crop the stems are more or less round in shape, possess nodes, internodes are generally hollow with scattered vascular bundles.
  • Leaves have ligule and auricle at the junction of lamina and leaf sheath. Some of the grassy weeds are as follows,

Echinochloa colonum

Echinochloa crussgalli

Setaria glauca

Digitaria longifolia

Dactyloctenium aegyptiacum

Cynodon dactylon
  • Saccharum munja
  • Eleusine indica
  • Eragrostis interupta
  • Paspalum scrobiculatum
  • Leersia hexandra
  • Eragrostis aspera

 
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Ikisan - Sedges In Rice

Sedges

  • Sedges are very similar to grasses but have three ranked leaves.
  • The stems are usually triangular and they won't possess nodes and internodes.
  • Several species have modified rhizomes which are used for food storage and propagation.

Some of the sedges are given below


Cyperus rotundus

Fimbristylis milliaceae


Cyperus iria

Cyperus difformis

  • Scirpus erectus
  • Cyperus haspan

Biological Control of Weeds

  • Certain insects and microbes feed on weeds and contributing to the weed control.

Some of the examples where the weeds are controlled through biological method are furnished below.

Weed Species
Natural Enemies
Cyperus rotundus Athesapenta cyperi (Rhizome and stem
 boring weevil), Bactra minima (Tertric stem borer), Bactra venesoma.
Salvinia molesta
(Water fern)
Grasshoppers (Paulinia acuminata)
Hydrilla, Chara
(Water fern)
White amur, Tilapia (Fishes).

 
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Ikisan - Broad Leaved Weeds Of Rice
Broad Leaved Weeds
  • Broad leaved weeds are usually dicots with tap root system.
    The stem has branches and leaves with a net venation.

Some of the broad leaved weeds are


Eclipta alba

Commelina benghalensis

Sphenoclea zeylanica

Monochoria vaginalis

Ludwigia parviflora

Aegetarum conyzoides
  • Eichornia crassipes
  • Salvinia molesta
  • Alternanthera sessilis
  • Ammanea baccifera

Details of Weeds in Rice

Common name
Botanical Name
Family
Plant Description
Habitat
Method of propa-gation
Suitable
herbi-cides
No of seeds
Goat weed Agera- tum cony- zoides Compo- sitae An erect branched annual Garden lands and wet lands By seeds like achenes 2,4-D ---
--- Astera-canta Longi- folia Acantha-ceae A tall herb with dense clusters of narrow leaves and long woody spines Rice field & Margins of tanks By seeds 2,4-D & 2,4,5-T ---
  Centella asiatica Umbelli- feraceae A prost-rate herb Rice fields along bunds of irri-gation chan-nels By bits of fruits 2,4-D ---
Cara-velle seed Cleome gynandra Cappa- ridaceae Annual Rice fallows & cultiv-ated lands seeds 2,4-D 8000
Tropical spider wort Com-melina bengha-lensis Comma-linaceae A Fleshy, branched perennial herb Culti-vated fields & waste lands seeds 2,4-D ---
Field bind weed Convo-lvulus arvensis Convol-vulaceae An obnoxious weed with a deep root system Culti-vated fields & waste places By seeds & Under ground stems --- 200 to 400 more
  Crota-laria quin-quefolia Legumi-naceae An errect annual herb Rice fields in coastal areas By seeds --- 2500
  Cyanotis axillaris Comme-linaceae A succulent annual herb In rice fields and moist situ-ations By seeds and bits of stem 2,4-D ---
Ber-muda grass or Dub grass Cynodon dactylon Grami-naeceae A perenneal hardy and much branched herb Culti-vated fields ,waste lands By grains & under ground stems Dala-pon TCA, Amitrol ---
Bulb grass Cyperus bulbosus Cype-raceae An errect herb growing in small clumps Culti-vated and waste places By bulbs & Nuts Chloro-picrin, Methyl bromide ---
  Cyperus difformis Cype-raceae An errect, tuffed, glabrous annual Rice fields By seeds --- ---
  Cyperus iria Cype-raceae An erect glabrous annual Rice fields, Marshy places and in ponds & ditches during mon- soon By seeds --- ---
Nut grass Cyperus rotundus Cype-raceae An erect, glabrous perennial herb Culti-vated lands & waste fields By seed like Nuts and under-ground stems Chloro-picrin,
methyl bromide
3000 / aerial shoot

 
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