Characterization and management of Botrytis cinerea inciting blossom blight of carnation under protected cultivation

Aim: The present study aimed to characterize the pathogen responsible for blossom blight of carnation, as well as to manage the disease effectively using fungicides. The investigation also included the study about the developmental biology of the pathogen in relation to environmental factors. Methodology : The pathogen was exposed to various environmental factors viz., light, relative humidity temperature in order to assess their relation. Identity of the pathogen was characterized by sequencing the 18S-28S rRNA genes. Efficacy of the fungicides was studied by in-vitro poisoned food technique. Their efficacy under protected cultivation was assessed throughfoliarspray Results : Field survey revealed severe blossom blight incidence at Nilgiris district, Tamil Nadu, India. Under in vitro conditions, the pathogen sporulated profusely at 15 degrees C, when exposed to alternate light and dark hours. The pathogen produced, scattered, large, dark, black, irregular, flat, smooth surfaced, sclerotial bodies, under dark at 20 degrees C. Morphological characterization and sequencing of the 18S-28S rRNA genes identified the pathogen to be Botrytis cinerea. Tebuconazole effectively inhibited the growth of the pathogen in vitro @ 5ppm concentration. Blossom blight incidence under protected cultivation was curtailed to a greaterextentbyfoliarspray with tebuconazole. Interpretation : Blossom blight caused by B. cinerea is an important post harvest pathogen that leads to huge loss. The present study regarding the relationship ofenvironmental factors with the developmental biology of the pathogen provides sufficient scope for future studies in designing effective management practices. Moreover, application of tebuconazole drastically reduced blossom blight incidence under protected cultivation.