The Indian Journal of Agricultural Sciences (Dec 2017)
Impact of organic manures, green leaf manures and micronutrients on natural enemies and energy use efficiency in cotton
Abstract
The field experiment was carried out at MARS, Dharwad during kharif 2010-11 and 2011-12 to study the impact of organic manures, green leaf manures and micronutrients on natural enemies, sucking pest population, energy use efficiency and energy productivity. Among the nutrient management practices, EC (1/3) + VC (1/3) + gliricidia GLM (1/3) equivalent to RDF recorded significantly higher natural enemies population mainly coccinellids, syrphid maggots, Micromus timidis, chrysoperla and spiders/plant (0.80, 1.05, 0.88, 0.72, 1.30 and 1.28) over RDF + FYM (0.35, 0.44, 0.44, 0.44, 1.13 and 0.53, respectively). The foliar spray of panchagavya @ 5% recorded significantly higher natural enemies population, viz. coccinellid adults, syrphid maggots, Micromus timidis, chrysoperla and spiders/plant (0.67, 0.72, 0.64, 1.27 and 1.04/plant, respectively) over bio-digester @ 20% (0.57, 0.64, 0.57, 1.16 and 0.96, respectively).The combined application of EC (1/3) + VC (1/3) + gliricidia GLM (1/3) equivalent to RDF with foliar spray of panchagavya @ 5% recorded significantly higher natural enemies population mainly coccinellid adults, coccinelid grubs, syrphid maggots, Micromus timidis, chrysoperla and spiders/plant (0.88, 1.13, 0.92, 0.75, 1.34 and 1.32/plant, respectively) as compared to RDF + FYM (0.25, 0.38, 0.36, 0.31, 0.74 and 0.31/plant, respectively). At 90 DAS, RDF + FYM @ 5 t/ha recorded significantly lower aphids and thrips populations (2.73, 1.42 per 3 leaves) over other nutrient management practices. The integrated application of EC (1/3) + VC (1/3) + gliricidia GLM (1/3) equivalent to RDN recorded significantly higher energy use efficiency and energy productivity (2.17 and 0.186 kg/MJ, respectively) over FYM @ 5 t/ha + RDF (2.05 and 0.174 kg/MJ). The combined application of EC (1/3) + VC (1/3) + gliricidia GLM (1/3) equivalent to RDN with foliar spray of panchagavya @ 5% recorded significantly higher energy use efficiency and energy productivity (2.27 and 0.194 kg/MJ, respectively) over RDF + FYM.
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