Control of Noxious Weed – Cyperus Rotundus L. (Nut grass, Nagar Motha)
This is one of the noxious weeds of the world, particularly in moisture retentive soils. The nut sedge shoots are strong enough to penetrate through potato tubers. Vegetable crops are worst effected by it, though it also infests other crops like maize, sugarcane cotton, etc.
Control Measures of Cyperus Rotundus:
Deep summer tillage is important in the control of nutgrass. It can be greatly improved by supplementing it with 2,4-D @2-4 kg/ha at last cultivation before the on set of monsoon. In rainy season fallow fileds infested with nutgrass tillage may continued to deplete the sedge of its food reserved. This is about the pre-flowering time of nutsedge. At this time food reverse in nutsedge tubers are low.
Competive cropping like sunhemp, spreading legumes etc are helpful in smothering nut sedge by cutting light to the weed.
Several herbicides like Glyphosate 2 kg ai/ha as post emergence can arrest the growth of nut sedge completely. While dalapon 4 kg /ha or 20 PPM brings about complete scorch and desiccate and thereby kills underground parts of nutsedge.
2,4-D ( Sodium) at 3 kg /ha can kill 80 to 90 % nutsedge while a mixture of 2,4-D (amine) 0.5 kg/ha. Plus MSMA 0.5 kg/ha can kill the basal bulbs and attached tubers. Nutsedge is susceptible to mixture of aimtrole 4.5 kg/ha plus Atrazine 2 kg/ha Dicamba 1 kg + 2 ,4-D, 2 kg/ha added with molasses at 3% spray can easily be translocated from mother to daudhter tuber and kill them completely.