Polymer coating for higher pesticide use efficiency, seed yield and quality in onion (Allium cepa)

Abstract

Onion seed crop is infected with several pest and diseases which reduce the seed yield and quality. The present study explores the feasibility of using polymer as an efficient delivery system for seed-protectant chemicals during onion seed production. Polymer coating prolonged the release of pesticides. After 30 DAP, 557% and 1087% higher retention of fungicide and insecticide was observed in polymer coated bulbs over traditional method of bulb treatment. Onion bulb coating with polymer and 0.15 % fipronil + 0.25 % (carbendazim + mancozeb) showed significantly higher values for seed yield attributes viz. productive scapes/plant (5.56), lower percent lodged scapes (21.16), seed yield/ plant (21.15 g) and seed quality attributes in comparison to control and traditional method of bulb treatment. Lowest percent disease index (36.39) was recorded in treatment- polymer coating + 0.15 % fipronil + 0.25 % (carbendazim + mancozeb) and lowest number of thrips/plant (5.14) was recorded in bulbs coated with polymer + 0.15 % fipronil + 500 ppm streptocyclin. Treating of onion bulbs with polymer is beneficial in increasing the efficacy of the applied pesticides, reducing the incidence of pest and diseases and enhancing seed yield and quality.