Weeds are the major yield reducing agent in sugarcane crop. The loss in the cane yield may go upto 60-80 per cent, depending upon the type of weed flora present and their intensity in an area.

 

Major weed: 

Sedges-	Cyperus rotundus
Grasses- Cynodon dactylon,Sorghum halepense, Panicum spp., Dactylocterium aegyptium,
Cynodon dactylon	Sorghum halepense		Panicum species
Broad leaved weeds - Chenapodium album, Convolvulus arvensis L., Amaranthus viridis L., Portulaca oleraceae L., Commelina bengalensis L., Trianthema portulacastrum L.
Trianthema portulacastrum L.	Commelina benghalensis		Chenopodium album
Weeds flora in sugarcane field competes for moisture and light also remove about 4 times N and P and 2.5 times of K as compared to crop during the first 50 days period. Weeds also harbour certain diseases and pests that attack sugarcane and thus lead to indirect losses. Doob grass (Cynodon dactylon), the pogan grass (Imperata cylindrica) are known to play as alternate hosts to ratoon stunting disease of sugarcane. Thus weeds essentially harm young sugarcane sprouts by depriving them of moisture, nutrients and sunlight. Poor growth of cane resulting from weed infestation also affects quality. Weeds that is present in the furrows i.e. along the cane rows causes more harm than those present in the inter-row spaces during early crop growth sub-periods. Thus the initial 90-120 days period of crop growth is considered as most critical period of weed competition. Therefore, the weed management practice adopted should ensure a weed-free field condition for the first 3-4 months period. Management: Autumn sown sugarcane: Spray of 2,4-D@1.0 Kgai/ha in 500-600 litres of water at 20-25 days after sowing. Spring sown sugarcane: Spray of Altrazine @ 2.0 Kgai/ha in 500-600 litres of water just after planting Spray of 2,4-D@1.0 Kgai/ha in 500-600 litres of water at 60 days after sowing