Management of chilli anthracnose by botanicals fungicides caused by Colletotrichum capsici

Abstract

Chloroform extract of Ginger (Zingiber officinale Roscoe.) rhizome, Clerodendrum (Clerodendrum infortunatum L.) mature leaf and methanol extract of Polyalthia (Polyalthia longifolia) mature leaf were tested against C. capsici radial growth, biomass production and spore germination on following poisoned food technique at 20, 100, 200 and 400 μg/ml and carbendazim at 1, 5, 10, 20μg/ml was taken as standard fungicide control. The effective concentration of plant extracts and fungicide carbendazim were also tested in vivo and field condition following artificial inoculation by pin-prick method of fully matured fruits about to ripe harvested chilli fruits. The extracts formulated with solvent and surfactant (20EC) were sprayed on harvested fruits both before inoulation and after inoculation and incubated in moist chanmer at 28±1 °C. Under field condition the botanical formulations were sprayed on chilli plnts bearing mature fruits both naturally and artificial inoculated conditions at 400μg/ml.All the plant extract formulations showed inhibition of radial growth, biomass production and spore germination with increased dose relationship. However, the fungicide carbendazim showed highest activity than the botanical formulations at lower doses. Under In vitro highest radial growth inhibition (57.78%) and spore germination inhibition (62.70%) at 400μg/ml was observed in polyalthia-methanol and highest inhibition of biomass production was observed in ginger-chloroform (32.78%). Under in vivo condition, all the treatments showed reduced lesion diameter but Clerodendrum-chloroform showed less lesion diameter compared to other treatments while in field condition both in natural infection and artificial infection, clerodendrum-chloroform showed less percent infected fruits in clerodendrum-chloroform followed by ginger-chloroform and polyalthia-methanol. Based on the results, the plant extract of Clerodendrum infortunatum could be developed and used as an effective alternative to synthetyic chemicals for postharvest anthracnose of chilli both under field and post-harvest condition.