Effect of VLCFA, ALS and 4-HPPD inhibitors on weeds, yields and economics of kharif hybrid maize (Zea mays L.) in Varanasi

Abstract

 A field experiment was conducted during the
kharif season of 2023–24 at Banaras Hindu University,
Varanasi, India, to evaluate the effect of VLCFA (very
long-chain fatty acid inhibitors), ALS (acetolactate
synthase 
inhibitors), 
and 
4-HPPD 
(4
hydroxyphenylpyruvate dioxygenase inhibitors) herbicides,
along with integrated weed management strategies, on
weed suppression, crop yields and economic in kharif
maize. The experiment followed a randomized block
design with twelve treatments and three replications.
Among the treatments, pyroxasulfone 127 g/ha fb hand
weeding at 25–30 DAS recorded the lower weed density
(3.32, 2.40 and 2.19 /m2), dry weight (1.03, 1.94 and
1.01) of grasses, sedges and broad leaved weeds,
respectively and weed index (4%) while achieving 96%
weed control efficiency. This treatment notably improved
number of leaves per plant, leaf area index, chlorophyll
content at 50 DAS, leading to higher grain (5.61 t/ha)
and stover yields (8.14 t/ha), outperforming atrazine
based treatments, which provided moderate weed
suppression, while raising concerns about herbicide
resistance. Economic analysis revealed that pyroxasulfone 127 g/ha fb hand weeding at 25–30 DAS had the higher
net return (120742 Rs./ha) and benefit-cost (B:C) ratio
(2.7), making it the most profitable weed management
strategy. The study concludes that application of
pyroxasulfone 127 g/ha fb hand weeding at 25–30 DAS,
offer effective, sustainable, and economically viable weed
control in Kharif maize under Varanasi’s agro-climatic
conditions.