Effect of Critical Crop Weed-Competition in Cotton (Gossypium hirsutum L.)

The field experiment was conducted at College Farm, N. M. College of Agriculture, Navsari Agricultural University, Navsari during 2020-21 and 2021-22. Study of critical crop-weed competition in cotton (Gossypium hirsutum L.) under south Gujarat condition. The treatment W6 (Weed free up to harvest) were recorded significantly higher plant height at harvest, number of sympodial branches per plant, seed cotton weight (g/plant), stalk weight at harvest (g/plant) and seed cotton yield (kg/ha) during 2020-21, 2021-22 and in pooled results. But treatment (W6) was statistically at par with the treatments W5 (Weed free up to 75 DAS), W4 (Weed free up to 60 DAS) and W7 (Weedy up to 15 DAS) in both the years and in pooled results. The magnitude of increase in seed cotton yield with weed free up to harvest treatment (W6) over weedy up to harvest treatment (W12) were to the tune of 67.82, 75.90 and 71.87% higher during 2020-21, 2021-22 and in pooled results. Number of monopodial branches per plant was found non-significant results in both the individual years and in pooled results. Significantly minimum total least nutrient depletion (Nitrogen, phosphorus and potassium) by weed was recorded under the treatment W6 (Weed free up to harvest), value were nitrogen 0.27, 0.23 and 0.25 per cent, phosphorus 0.07, 0.06 and 0.06 per cent, potassium 0.38, 0.32 and 0.35 per cent during both individual years and in pooled results, respectively. But it remained at with the treatments W5, W4 and W7. Whereas, total highest nutrient depletion was recorded under the treatment W12 (Weedy up to harvest), value were nitrogen 13.34, 11.35 and 12.34 per cent, phosphorus 3.01, 2.73 and 2.87 per cent, potassium 14.37, 12.19 and 13.28 per cent during 2020-21, 2021-22 and in pooled results, respectively.