Phytotoxicity, yield and economics of castor as influenced by different weed management practices

In kharif 2020, a field experiment on clay soils with the title Studies on effect of weed management practices in castor (Ricinus communis L.) was carried out at the Agricultural College Farm in Bapatla. The results showed that the treatment providing pre-emergence application of alachlor @ 1.5 kg a.i ha-1 fb chlorimuron @ 10 g + propaquizafop @ 63 g a.i ha-1 as post emergence at 30 DAS (T9) as well as pre-emergence application of alachlor @ 1.5 kg a.i ha-1 fb halosulfuron @ 67.5 g a.i + propaquizafop @ 63 g a.i ha-1 as post emergence at 30 DAS (T10) were significantly highest seed yield, gross return, net returns, and B:C ratio under the treatment hand weeding at 20 and 40 DAS (T2). The treatments comprised of pre and post emergence herbicides like alachlor, chlorimuron, halosulfuron and propaquizafop were found to be selective to castor rendering no phyto toxicity sysmptoms and crop injury.