Polymer film coating mediated delivery of pesticide enhances germination, vigour and shelf life of cowpea seeds under biotic stress and natural ageing

Abstract

Cowpea seeds are highly susceptible to insect and pathogen in storage and in the field as well. Synthetic polymer based film coating was envisaged to provide external protection from natural stresses (abiotic and biotic) by holding plant protectants onto the seeds. Seeds were coated through a commercial seed coating machine with different combination of fungicide (F:bavistin @ 2 g/ kg seed), insecticide (I:malathion @ 2 g/kg seed), synthetic polymer (@ 6 ml/kg seed) and neem seed kernel extract (NSKE @ 10 ml/kg seed). Chemical plant protectants and polymer, when used alone reduced the germination at initial germination test, which recovered afterwards. After seed storage for three, six and nine months, film coated plant protectants provided better protection to the seeds, in terms of germination and seed vigour. Induced feeding of seed to pulse beetle/ bruchid (Callosobruchus chinensis) was conducted to test the efficacy of film coating. Film coating with plant protectants exhibited better performance over control in terms of seed damage, oviposition and number of holes created by beetles on the seed surface, as well as with increase in vertical depth in seed container.