Vol. 10, Issue 10 (2021)

Author(s):
Devabhathineni Mounica, Sakthivel N, Karthikeyan R and Ravichandran V

Abstract:
The limited land resource in rice-fallow condition is to be efficiently utilized and cultivation of rice-fallow cotton is one such option. Weeds are the most dominant pests in rice-fallow cotton cultivation. To control the weeds effectively, a field experiment was conducted in rice-fallow cotton with different herbicides viz., Pendimethalin, Quizalofop ethyl, Pyrithiobac sodium, Paraquat dichloride and their combinations. Results of field investigation revealed that all growth characters (plant height, LAI, DMP), chlorophyll content, sympods plant^-1, seed cotton yield and weed control efficiency were significantly higher in weed-free check (T₉) than others. Among treatments, Pendimethalin @1.0 kg a.i. ha^-1 as pre-emergence and Quizalofop ethyl @ 50g ha^-1 at 20 DAS (T₂), Pendimethalin @1.0 kg a.i. ha^-1 as pre-emergence along with combination of Quizalofop ethyl @ 50g ha^-1 and Pyrithiobac sodium @ 62.5g a.i. ha^-1 at 20 DAS (T₄) and combination of Quizalofop ethyl @ 50g a.i. ha^-1 and Pyrithiobac sodium @ 62.5g a.i. ha^-1 at 20 DAS (T₅) registered significantly higher values of above measured parameters compared to all other weed management treatments and control. Hence, combined use of Pendimethalin and Quizalofop ethyl (or) Quizalofop ethyl and Pyrithiobac sodium (or) together use of these three herbicides effectively controls the weeds in rice-fallow cotton increases the growth and yield of cotton.