Performance of Plant Aqueous Extracts for Organic Weed Management in Groundnut (Arachis hypogaea)

Different crops were raised and harvested at physiological maturity and weeds were collected at flowering stages during Kharif 2017 for preparing plant aqueous extracts at wet land farm of Sri Venkateswara Agricultural College, Tirupati. A field experiment was conducted to evaluate the performance of different plant aqueous extracts and paddy straw mulch for organic weed management in a randomized block design and replicated thrice during Rabi, 2017-18 and The predominant weed species observed were Cyperus rotundus L. (45%), Digitaria sanguinalis (L.) Scop. (15%), Borreria hispida (L.) K. Schum. (7%). All chemical weed management practices recorded significantly lesser weed density and dry weight than organic weed management practices. Among the organic weed management practice, application of paddy straw mulch at 5 t ha(-1) recorded significantly lesser density and dry weight of weeds with higher weed control efficiency, apart from enhancing the yield components and pod yield of groundnut. Among the plant aqueous extracts, sorghum plant aqueous extract spray 15 L ha(-1) at 15 and 30 DAS proved to be the best in controlling weeds and increasing pod yield. The performance of parthenium and purple nutsedge aqueous extracts each applied at 15 L ha(-1) at 15 and 30 DAS were very poor in controlling weeds and promoting pod yield of groundnut. The reduction in pod yield of groundnut due to unchecked weed growth was 52.53 and 37.18% compared to pendimethalin 1 kg ha(-1) + HW at 30 DAS and paddy straw mulch at 5 t ha(-1), respectively. Paddy straw mulch at 5 t ha(- 1) recorded significantly higher count of effective rhizobium nodules plant-1 and soil microorganisms viz., bacteria, fungi and actinomycetes.