Integrated Pest Management

               Invasive non-native plants are a serious threat to native species, communities, and ecosystems in many areas around the world. Integrated Weed Management (IWM) uses all available weed control strategies in the best possible way to manage weed populations. Such strategies include cultural, biological, mechanical and chemical methods of weed control.

GRASSY WEEDS

Agropyron repens

Quak Grass

• Aggressive perennial grass with long slender white rhizomes;

• Rhizome tips are yellowish and sharp-pointed; base of leaf blade with claw-like appendage that clasps the stem; spikelets, up to 15 cm long, are in 2 long rows borne flat wise to the stem                                 

Avena fatua

Wild Oat (Jangli Jai)

• Annual grass with hollow erect stems from 0.3 to 1 metre tall

• Leaves of seedlings twist counter-clockwise when viewed from above;

• Yellow to black seeds with a bent, twisted bristle (awn); seeds with a circular scar (sucker mouth) at the base                            

Brachiaria spp

Para Grass

• Perennial with a semi-erect growth habit, spreading by rooting from lower culm nodes.

• Leaf blade is linear-triangular in shape, broad, dark green, both abaxial and adaxial surfaces densely covered with long hairs.

• Inflorescence is a panicle 12 cm long, with 4-8 racemes about 6 cm long, and spikelets arranged in two rows on each raceme                                

Dactyloctenium aegypticum

Crow Foot Grass  (Makda) 

• The stem has a spreading, creeping and mat-forming structure.

• It roots at the lower nodes.

• The flower head has 2-7 spikelets borne at the tip of the stem.

• The seed head looks like a crow's foot, hence the name.

• Each plant may produce up to 60,000 seeds.                                 

Digitaria sanguinalis

Crab Grass

• The leaf sheaths of large crabgrass seedlings are tinged purple and are covered with long, stiff hairs.

• Large crabgrass is purplish or green and has very hairy leaves and sheaths.

• Leaves are 6 to 8 mm wide and 5 to 15 cm long.

• Blades are flat and both surfaces are covered with dense hair.

• Dense hairs which occur at a 90 degree angle to the stem.

• This weed has a prolific branching habit.                              

Saccharum spontaneum

Wild cane

• A stout, erect perennial, up to 6 m. high

• Stem are solid above, fistular below, polished

• Leaves are erect, glaucous, midrib white

• Spiklets are in pairs l2-7 mm long, awnless, sessile.                           

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 Elusine indica

Goose Grass or Wire Grass (Kodo)

• It is an annual that grows as a compressed plant.

• It appears as a whitish silvery mat, forming a pale green clump with flattened stems in a low rosette. 

• Leaves have a short membranous ligule.

• Flower stalks are short, stout, and compressed. 

• It is normally found in compacted areas or areas of  heavy wear.

                                

Echinochloa colonum

Water Grass/ Jungle Rice(Sava)

• Junglerice, a summer annual grass, is 2 to 3 feet (60-90 cm) tall.

• Seedling leaves are grayish or dull green. 

• It is closely related to barnyard grass and looks similar except for the distinctive purple bands on leaves.

Echinochloa crusgalli

Barnyard Grass (Sava)

• Barnyard grass is a summer annual that propagates by seed.

• It grows in clumps by rooting and branching at the lower joints of the stems

• It grows 1 to 4 feet tall.

• The stems are smooth and stout, thick and flattened

• The leaves are green with reddish cast, they are flat and 8 to 50 cm long and 8 to 20 mm wide, are smooth on both sides but rough towards the top.

• These are hairless

• Flower heads are extremely variable, but they often droop slightly with lower flower branches further apart than upper ones.

Setaria glauca

Yellow Fox Tail (Bandra Bandri)

• Yellow foxtail is a shallow-rooted summer annual grass that reproduces by seeds.

• Mature foxtail plants are 1 to 3 feet (30 - 90 cm) tall,  with branching and some spreading at their bases. 

• A major identifying characteristic of yellow foxtails is the straggly white hairs clustered near the base of the base of the upper leaf surface.

• Leaf blades are 4 to 15 inches (10 - 37.5 cm) long, and most have a spiral twist. 

• Flower heads are dense spikes with yellow to reddish bristles.

Cynodon dactylon 

Bermuda grass (Dooba or Haryali Grass)

• Bermudagrass is a perennial grass.

• The plant grows rapidly when temperatures are warm and moisture is abundant. 

• The mature plant forms dense mats with spreading and branching stolons that root at the nodes. 

• The flowering spikes of bermuda grass radiate from a single point at the tip of the stem. 

• The collar region of bermuda grass has a fringe of short, white hairs.

• It spreads rapidly by seed and runners and even small fragments will root if dumped with garden refuse.

SEDGES

Cyperus diffusus

Nut Sedge (Motha)

• Nutsedges are perennial weeds resemble grasses.

• It grow mainly from tubers or "nutlets" formed on rhizomes, mostly in the upper foot of soil.

• Leaves are V-shaped in cross section and arranged in sets of three at the base. Stems are triangular in cross section.

• Tubers of yellow nutsedge are produced singly while purple nutsedge tubers are produced in chains, several on a single rhizome                               

Cyperus esculentus

Yellow Nut Sedge (Motha)

•  Yellow nutsedge emerges as a pale green spike, similar in appearance to a grass seedlings.

• Yellow nut sedge is an erect, grasslike perennial.

• The leaves arise from a central triangular stem to form a clump that grows 1 to 3 feet high.

• Leaves are V-shaped, 3 to 12 mm wide, yellow-green, smooth and shiny or waxy on the upper surface.

• Yellow nutsedge seed heads are straw coloured                               

Cyperus rotundus

Nut Grass or Coco Grass (Motha)

• Although nutsedges are often referred as "nutgrass" and resemble grasses, they are not grasses but true sedges. 

• Their leaves are thicker and stiffer and are arranged in sets of three at the base.

• Nutsedge stems are solid, and when looked at in cross section, they are triangular.

• Nutsedge has three long, leaf like bracts at the base of each flower head. 

Methods of Weed Control

Cultural Control

• Summer ploughing 2-3 times and leave the field for solarization
• Solarization can be done by giving light irrigation in morning and then covering the field by polythene so that the weeds are killed due to heat effect. 
• Prepare stale seed bed and allow the weeds to germinate either by irrigation or pre monsoon shower and then killing them by shallow harrowing.
• Always use certified and weed free seeds.
• Timely sowing should be done.
• Narrow row spacing and higher seed rate is effective in reducing weed growth.
• Line sowing should be done to facilitate inter-culture operations.
• Plant population should be maintained to its optimum right from its beginning to minimize the crop weed competition.
• Inter-culture operation-using hoe to remove all the weeds in between the row.
• Mulches like straw hay etc can be used and then these can be placed in between the rows to suppress the weed growth.

Mechanical Control

• Two hand weeding can done
• Hand weeding either by hand pulling or with the help of khurpi.
• Sick-ling is done when sufficient labour is not available.

Biological Control

• Improved and competative grasses like Setaria, Guinea grasses should be planted after herbicide application.
• Common purslane plants that have been attacked by the purslane sawfly produce fewer seeds and are much less competitive with garden and crop plants. 
  

Chemical Control

• Two hand weeding along with two interculture by kolpa + diuron 0.75 or pendimethalin 1.5 kg/ha.
• Pre Planting Incorporation of Fluchloralin at 0.9 to 1.2 kg/ha controls mix weed flora.
• An application of 750 ml Diuron 80 WP/ha as Pre-emergence (PE) in 700 - 800 l water/ha.
• An application of pendimethalin as Pre-emergence (PE)1.5 kg/ha is also found effective in controlling the weed population. 
  OR
• Pre-emergence (PE) application of alachlor at 2.0 to 2.5 kg/ha.