Study of critical crop-weed competition in cotton (Gossypium hirsutum L.) under south Gujarat condition

The field experiment was conducted at College Farm, N. M. College of Agriculture, Navsari Agricultural University, Navsari during 2020-21 and 2021-22. To Study of critical crop-weed competition in cotton (Gossypium hirsutum L.) under south Gujarat condition. There were twelve different critical crop weed competition treatments and randomized block design with three replications. The treatment W₆ (Weed free up to harvest) was recorded significantly higher plant height (cm), number of sympodial branches per plant, number bolls per plant, boll weight (g), seed cotton yield and stalk yield during both the years and in pooled results. Significantly maximum weed control efficiency and minimum weed index was also recorded under the weed free up to harvest treatments (W₆) during both the years and in pooled results. The treatments W₅ (Weed free up to 75 DAS), W₄ (Weed free up to 60 DAS) and W₇ (Weedy up to15 DAS) effective proved for higher plant height, number of sympodial branches per plant (cm), number bolls per plant, boll weight (g), seed cotton yield and stalk yield, weed control efficiency (%) and weed index (%). The treatment W₁₂ (Weedy up to harvest) recorded lower growth parameters, yield attributes and yields parameters, weed index and weed control efficiency during both the years and in pooled results. Weed index during 2020-21 (40.40%), 2021-22 (43.13%) and in pooled results (41.77%) was recorded under treatment W₁₂ (Weedy up to harvest) it indicates the percentage reduction in seed cotton yield due to heavy weed infestation compared to a weed-free plot.