Influence of Post Emergence Application of Herbicides on Growth, Yield and Economics of Dry Direct Sown Rice

Abstract

The field trial was conducted on sandy clay loam soils of agricultural research station Ragolu, A.P. India during two consecutive Kharif seasons of 2015 and 2016 .The trial was conducted in Randomized Block Design with three replications and nine treatments Viz., T1- post emergence application of Bis-pyribac sodium @ 25 g ai/ha at 20 DAS fb Amine salt of 2,4 D @ 0.58 kg ai/ha at 40 DAS; T2- post emergence application of Bis-pyribac sodium @ 25 g ai/ha at 20 DAS fb metsulfuron methyl + chlorimuron ethyl (Almix) 4 g ai/ha  at 40 DAS; T3- post émergence application Bis-pyribac sodium @ 25 g ai/ha at 20 DAS fb Ethoxysulfuron @ 20 g ai/ha  at 40DAS ; T4- post emergence application Bis-pyribac sodium @ 25 g ai/ha at 20 DAS fb  postemergence   application  of Fenoxaprop P ethyl with safenor (Rice star) @ 625ml/ha at 40 DAS ; T5- post emergence application Bis-pyribac sodium @ 25 g ai/ha at 20 DAS fb postemergence application  of Cyhalofopbutyl @100 g ai/ha + amine salt of 2,4, D @ 0.58  kg ai/ha at 40 DAS; T6- post emergence application Bis-pyribac sodium @ 25 g ai/ha at 20 DAS fb Ethoxysulfuron  @ 20 g ai/ha+ Fenoxaprop PEthyl with safenor (Rice star) @ 625ml/ha at 40 DAS; T7- Post emergece application  of Penoxulam@  25g ai/ha at 20 DAS fb amine salt of 2,4, D   @ 0.58 kg ai/ha at 40 DAS ;T8-  Two hand weedings at 20 & 40 DAS  and T9- Weedy Check. The study in dry direct sown rice on weed management by herbicides revealed that, uncontrolled weed growth in dry direct sown rice reduced the grain yield by 46 to 54 percent. Post emergence application of Bis-pyribac sodium @ 25 g ai/ha at 20 DAS  followed by Ethoxysulfuron  @ 20 g ai/ha+ Fenoxaprop P Ethyl with safenor (Rice star) @ 625 ml/ha  at 40 DAS  resulted into taller plants, maximum number of tillers/m2, The highest dry matter production at harvest, more number of panicles/m2 filled grains/panicle, 1000 grain wt, higher grain yield (82-108 %t over weedy check) Straw yield besides  higher gross returns net returns and B:C ratio  among different herbicide treatments.