Weed management in maize with new generation herbicides under vertisols of Rajasthan

Abstract

A field experiment was conducted at Research Farm of Agricultural Research Station, Ummedganj, Kota (Agriculture University, Kota), Rajasthan, India during Kharif 2017 and 2018, with the objective to find out effective post-emergence new generation herbicides for controlling weeds as season long and increasing the productivity of maize under vertisols of Rajasthan. The treatments comprised of T1: Weedy check, T2: Hand weeding twice (20 & 40 DAS), T3: Atrazine 50% WP @ 0.5 kg a.i./ha (PE), T4: Bentazone 48% SL @ 1.2 kg a.i./ ha (15-20 DAS), T5: Tembotrione 42% SC @ 120.75 g a.i./ha (15-20 DAS), T6: Tembotrione 42% SC @ 150.95 g a.i./ha (15-20 DAS), T7: Topramezone 33.6% SC @ 25.2 g a.i./ha (15-20 DAS), T8: Topramezone 33.6% SC @ 31.5 g a.i./ha (15-20 DAS), T9: Tembotrione 42% SC @ 120.75 g a.i./ha +Atrazine 50 WP @ 0.5 kg a.i./ha (1520 DAS) and T10: Topramezone 33.6% SC @ 25.2 g a.i./ ha + Atrazine 50 WP @ 0.5 kg a.i./ha (15-20 DAS). Results showed that the application of Topramezone 31.5 g a.i./ha at 15-20 DAS recorded significantly minimum weed density, weed dry weight and maximum weed control efficiency at 30 & 60 DAS being at par with Tembotrione 150.95 g a.i./ha followed by Topramezone 25.2 g a.i./ha and Tembotrione 120.75 g a.i./ha, which were at par with hand weeding twice at 20 & 40 DAS over rest of the treatments. Maximum yield attributes viz., no. of cobs/ plant, no. of grains/cob, 100-grain weight and grain yield was recorded with the Topramezone 31.5 g /ha at 15-20 DAS and being on par with Tembotrione 150.95 g a.i./ha, Topramezone 25.2 g a.i./ha, Tembotrione 120.75 g a.i./ha and hand weeding twice at 20 & 40 DAS over rest of the weed management practices. Post emergence application of Topramezone 31.5 g a.i./ha at 15-20 DAS also fetched significantly higher net returns (Rs. 66503/ha) and B:C ratio to the tune of 207.39 & 158.33 per cent, respectively over weedy check and being on par with Tembotrione 150.95 g a.i./ha, Topramezone 25.2 g a.i./ha, Tembotrione 120.75 g a.i./ha, Tembotrione 120.75 g a.i./ha + Atrazine 0.5 kg a.i./ha, Topramezone 25.2 g a.i./ha + Atrazine 0.5 kg a.i./ha and hand weeding twice at 20 & 40 DAS.