Impact of organic fertilization and weed management practices on weed control efficiency and yield of Cotton (Gossypium hirsutum L.)

A field experiment was conducted during winter, irrigated, season 2015-16 and 2016-17, to find out the effect of organic manures and weed-management practices on yield and yield attributes of (Gossypium hirsutum L.) upland cotton at Coimbatore, Tamil Nadu. The treatments were laid out in a strip-plot design and replicated thrice. Four organic manures, viz., farmyard manure, vermicompost, goat manure, and composted poultry manure, were assigned to main plots and 4 weed-control treatments, viz., hand-weeding, twin wheel hoe weeding, power weeder weeding and weedy check, to subplots. Application of 100% recommended dose of nitrogen (RDN) through composted poultry manure resulted in significantly lower weed density (23.60 No./m2), higher weed-control efficiency (85.89%), better yield attributes and higher yield (1484 kg/ha) followed by 100% RDN through goat manure. Hand-weeding at 20 and 40 days after sowing (DAS) followed by power-weeder weeding at 20 and 40 DAS enhanced the yield of cotton owing to reduction in weed growth and nutrient depletion by weeds and increased nutrient uptake by the crop. Hence considering the yield and yield attributes of cotton, it could be concluded that 100% RDF through composted poultry manure along with 2 power weeder weeding or hand-weeding at 20 and 40 DAS could reduce the weed density and dry weight and result in higher yield and help in maintaining sustainable soil fertility under irrigated condition in cotton.