Herbicides and herbicide combinations for management of Leptochloa chinensis in wet-seeded rice

An experiment was conducted to evaluate the efficiency of various herbicides for the management of chinese sprangletop (Leptochloa chinensis) at Integrated Farming System Research Station, Karamana, Thiruvananthapuram of Kerala Agricultural University, India during Kharif (rainy season) 2018 and 2019. Grass weeds were the most dominant weed species followed by broad-leaf weeds and sedges during both the crop seasons. The present study revealed that fenoxaprop- p-ethyl at 60 g/ha was the most effective herbicide against L. chinensis followed by cyhalofop-butyl at 80 g/ha. Dry matter production of L. chinensis was lower in sole application of fenoxaprop-p-ethyl at 60 g/ha and cyhalofop-butyl at 80 g/ha compared to their tank mix combination with bispyribac-sodium at 25 g/ha during both the years. Ready-mix combination of penoxsulam + cyhalofop-butyl (6% OD) at 150 g/ha was very effective in managing the complex spectrum of weeds however, it was not effective in managing L. chinensis compared to other herbicidal treatments. Application of bispyribac-sodium alone at 25 g/ha was not effective in controlling L. chinensis resulted in lower weed control efficiency of 37 and 48% during 2018 and 2019, respectively. Tank mix application of bispyribac- sodium with fenoxaprop-p-ethyl (at 25 + 60 g/ha) or cyhalofop-butyl (at 25 + 80 g/ha) recorded the least total dry matter production of weeds. All the tested herbicides and the herbicide combinations increased the grain yield compared to unweeded control during both the years.