Impact of Weed Management Practices on Yield Attributes, Economics and Phytotoxicity of Kharif Maize

A field experiment was conducted during 2018 and 2019 at Tamil Nadu Agricultural University, Agriculture College and Research Institute, Coimbatore to study the impact of weed management practices on yield attributes, economics and phytotoxicity of kharif maize. Ten treatments were tested in randomized block design with three replications viz., pre emergence (PE) atrazine at 0.5 kg a.i. ha-1 fb hand weeding (HW) at 20 DAS, PE atrazine at 0.5 kg a.i. ha-1 fb power weeder (PW) at 20 DAS, PE atrazine at 0.5 kg a.i. ha-1 + pendimethalin at 1 kg a.i. ha-1 (Tank mix), PE atrazine at 0.5 kg a.i. ha-1 + pendimethalin at 1 kg a.i. ha-1 fb HW at 20 DAS, early post emergence (EPoE) topramezone at 25.2 g a.i. ha-1, PE atrazine at 0.5 kg a.i. ha-1 fb EPoE topramezone at 25.2 g a.i. ha-1, EPoE tembotrione at 122 g a.i. ha-1, PE atrazine 0.5 kg a.i. ha-1 fb EPoE tembotrione 122 g a.i. ha-1, hand weeding twice at 20 and 45 DAS and control (weedy check). Among the different weed management practices significantly higher yield attributes viz., cob length, cob girth, weight of cob, No. of grain rows cob-1, No. of grains cob-1, grain yield cob-1 was found with hand weeding twice at 20 and 45 DAS and it was at par with atrazine at 0.5 kg a.i. ha-1 as PE fb topramezone at 25.2 g a.i. ha-1 as EPoE and atrazine at 0.5 kg a.i. ha-1 as PE + tembotrione at 122 g a.i. ha-1 as EPoE. Maximum net return and B:C ratio were recorded under atrazine at 0.5 kg a.i. ha-1 as PE fb topramezone at 25.2 g a.i. ha-1 as EPoE followed by atrazine at 0.5 kg a.i. ha-1 as PE + tembotrione at 122 g a.i. ha-1 as EPoE. However, among the different herbicidal treatments used, all the herbicidal treatments were found to be safe to the maize crop without any caused phototoxic effect on maize during both the years of experimentation. Now-a-days, increased labour scarcity and costs are encouraging farmers to adopt labour and cost- saving options by using chemical method.