Vol. 10, Issue 1 (2021)

Author(s):
D Swain and BR Nayak

Abstract:
An experiment was carried out at RRTTS, Mahisapat, Dhenkanal,Odisha during the kharif season of two consecutive years, 2018 and 2019 to study the efficacy of new generation herbicides on density of weed flora, crop yield as well as economics in transplanted rice under medium land condition in mid central table land zone in Odisha. Weed free treatment recorded significantly the lowest weed dry weight. Among the different herbicides weed management practices, pendimethalin @ 0.75 kg a.i./ha fb chlorimuron ethyl + metasulfuron methyl @ 4 g a.i./ha recorded significantly lower dry weight of weeds as compared to rest of the herbicidal treated plots but it was at par with pendimethalin @ 0.75 kg a.i./ha fb one HW at 20 and 40DAS. In case of weed control efficiency, pendimethalin @ 0.75 kg a.i./ha fb chlorimuron ethyl + metasulfuron methyl @ 4 g a.i./ha (79.95 kg ha-cm^-1) was significantly higher value of weed control efficiency than that rest of the herbicidal treated plots. The higher grain yield was obtained in pendimethalin @ 0.75 kg a.i./ha fb chlorimuron ethyl + metasulfuron methyl @ 4 g a.i./ha(4.81 t/ha) which was at par with pendimethalin @ 0.75 kg a.i./ha fb bispyribac sodium (20g a.i./ha) (4.62 t /ha) and significantly superior to rest of the herbicide treatments.The higher benefit: cost ratio(1.78) was obtained from pendimethalin @ 0.75 kg a.i./ha fb chlorimuron ethyl + metasulfuron methyl @ 4 g a.i./ha. Overall, the combination of pendimethalin @ 0.75 kg a.i./ha fb chlorimuron ethyl + metasulfuron methyl @ 4 g a.i./ha is economically profitable (4.81 t/ha) as compared to other chemical treatments for successfully controlling the complex weed flora under transplanted conditions.