EFFICACY OF SUNFLOWER RESIDUES AND HERBICIDES IN CONTROLLING WEEDS IN TRANSPLANTED RICE

Abstract

The experiment was conducted at Agronomy Field Laboratory of Patuakhali Science and Technology University, Dumki, Patuakhali, Bangladesh  from July 2018 to November 2018 to find out the effect of sunflower residues and herbicides on weed control and yield of T. Aman rice. Weed control methods tested were T 1 = weedy check,T 2 = Weed free check, T 3 = Pendimethalin,T 4 = Pretilachlor,T 5 = Butachlor,T 6 = Pyrazosulfuron ethyl,T 7 = Bensulfuron methyl + Acetachlor,T 8 = Bispyriback sodium,T 9 =2,4-D amine,T 10 =MCPA,T 11 = Sunflower residues ,T 12 = Sunflower residues + 100%Pyrazosulfuron ethyl,T 13 = Sunflower residues + 75%Pyrazosulfuron ethyl,T 14 = Sunflower residues + 50%Pyrazosulfuron ethyl. The weed spectrum of the experimental field consisted of all the three groups of weeds viz., grasses (15.78%), sedges (59.02%) and broad-leaved weeds (25.2%). The dominants weeds were Cynodon dactylon and Echinochloa crusgalli among grasses; Cyperus difformis , Fimbristylis miliacea and Scirpus supinus among sedges and Jussiaea decurrens among broad-leaved weeds.  Hand weeding recorded the highest weed control efficiency (99.05%) and weedy check recorded the lowest. Among different herbicides applied alone, butachlor had the highest weed control efficiency (87.59%).Hand weeding produced the highest grain yield (5.14 t ha -1 ) which was statistically similar to butachlor, pendimethalin, pretilachlor,  bensulfuron methyl + acetachlor and sunflower residues  + 100% pyrazosulfuronethyl.  Application of sunflower residues along with the reduced rate (75 or 50%) of pyrazosulfuron ethyl had effective weed control and satisfactory yield comparable to butachlor. The farmers can use this technology as an eco-friendly approach in transplanted Aman rice field.