Weed control in wheat: assessment of herbicide efficacy, economic, and yield impacts

Weed management in wheat under subtropical climate with moderate to high rainfall is challenging. The diverse weed flora in wheat ecosystem emerges in several flushes, necessitating sequential application of herbicides. A study was conducted during 2021–22, at D block farm under the aegis of Bidhan Chandra Krishi Viswavidyalaya, using randomized block design and replicated four times with a total number of nine treatments consisting of different combinations of pre (PRE) and post-emergence (POST) herbicides. Our experiment results showed that the sequential application of pendimethalin 1.0 kg ha−1, a high-effective pre-emergence herbicide followed by a post emergence herbicide metribuzin 0.2 kg ha−1, was effective in controlling both grasses and broadleaf weeds. It exerted significantly higher grain yield (4.34 t ha−1) of wheat with the highest weed control efficiency. This result was statistically at par with pendimethalin followed by one-hand weeding at 30 days after sowing (DAS) and sulfosulfuron + metsulfuron 32 g ha−1 at 30 DAS. The combination of these herbicides not only controlled the weeds effectively but also had similar effects on plant height, plant dry matter, leaf area index, and the crop resistance index of wheat. The highest profitability ($831.58 ha−1) and benefit: cost (2.05) were recorded with the application of sulfosulfuron + metsulfuron 32 g ha−1 at 30 DAS. Thus, combine application of sulfosulfuron + metsulfuron could provide an efficient, economic and sustainable weed management option for wheat cultivation in medium lowland under moderate rainfall conditions in the new alluvial zone of Indo-gangetic plain.