Effect of Seed Rate and Weed Management Practices on Weeds And Productivity of Late Sown Wheat (Triticum Aestivum L.)

Abstract

Wheat is an important prime cereal crop among the food-grain is grown in an area of29.65 m ha in India, with the production 93.5 million tonnes and average productivity 3 I .53 q ha·1 .Among several causes of low productivity in Uttar Pradesh, adoption of rice-wheat rotation is one. The preceding crop like sugarcane, potato, paddy and tori a etc., vacate the field late after normal sowing date of wheat and enforce the crop to be sown as much late as in the end of December and beginning of January. Late sown crop experiences high temperature, declining relative humidity and hot dissecting winds in later stage of crop growth, particularly during grain filling stage. Late sowing of wheat tends to reduce germination count due to low temperature, also reduce tillers unir1 area because of rise in temperature during tillering phase of the crop and consequently increase in the temperature at milking stage of the crop is the major threat affecting the productivity adversely. To mitigate the deleterious effect of delayed sowing, increasing seed rate will be a viable and economic option to compensate the reduction germination count and number of tillers per unit area. Keeping above facts in view, the present investigation conducted with the aim of assessing the effect of seed rate and weed management practices on weed dynamics, growth and yield of wheat, nutrient uptake by crop and weeds and economic feasibility of wheat cultivation under different treatments at SVPUAT, Meerut on sandy loam soil, low in organic matter, available nitrogen and medium in available PK, during 2012-13 and 2013-14. Treatment comprised of three seed rates viz. , 100, 125, and I 50 kg ha·1 in the main plot and six weed management practices viz. , Sulfosulfuron 25 g ha· 1, Sulfosulfuron + metsulfuron (30 + 2 g ha-1) , Clodinafop + metsulfuron (60 + 4 g ha-1), fenoxaprop-p-ethyl + Metribuzin (120 + 210 g ha"1 ), two hand weeding (120 and 40 DAS) and weedy check in sub-plots. The experiment was laid out in split plot design with three replications. Sowing with I 50 kg ha·1 seed rate recorded minimum density, dry weight, NPK content of weeds and removal, while plant height ,number oftiller m· 1 row length, leaf area index, dry matter accumulation by crop, no. of spike m·2 ,yield, gross return, net return and B: C ratio was significant!~ higher than I 00 and 125 kg ha·1 seed rate. Two hand weeding recorded minimum weed density, dry weight and nutrient removal which was at par with Clodinafop + metsulfuron (60 + 4 g ha-1 ), fenoxaprop-p-ethyl + Metribuzin ( 120 + 210 g ha· 1)and significantly lower than rest of the weed management practices. plant height, number of tiller m·1, leaf area index, dry matter accumulation by crop, numbe~ of spike m·2 yie~d, · NPK uptake by crop and B:C ratio also found significantly higher with two hand weed1~g were. at ~ar w1th Clodinafop + metsulfuron (60 + 4 g ha"1), Sulfosulfuron + metsulfuron (30 + 2 g ha· ) and s1gmficantly higher with fenoxaprop-p-ethyl + Metribuzin ( 120 + 210 g ha-1 ), Sul:osulfuron 25 g m h~-l and we~dy check. F h I+ M t "buz·1n (120 + 210 g ha-1 enoxaprop-p-et y e n ) being phytotOXIC to wheat plants ytelded gram at par to d I k To ·nsttre maximum grain yield and remuneration from late sown wheat crop, crop may be wee y c 1ec . 1 · h ·•) h b" ·d fi sown with 150 kg ha·l seed rate and application of Clodinafop + metsulfuron (60 + 4 g a er tct e or effective weed c::olh