First report of leaf spot disease caused by Botrytis cinerea on Piper longum.
During a survey of diseases of medicinal plant, a leaf spot disease was observed on Piper longum. Infected leaves of P. longum were collected from Biotech Green Herbal and Medicinal Plant Nursery, Kolhupani, Uttarakhand. Symptoms on leaves first appear as round, irregular straw to pale brown spots which later on turn into brown blighted areas, often with concentric rings. The pathogenicity tests were conducted by spraying healthy leaves of P. longum with conidial suspension. Control plants were sprayed with distilled water. The first leaf spots appeared after a period of 10± days after inoculation. The pathogen was reisolated from the infected leaves, identified and maintained on potato dextrose agar thus, confirming Koch's postulates. Based on morphological characteristics and pathogenicity tests, the organism was identified as Botrytis cinerea. This is thought to be the first report of B. cinerea causing leaf spot on P. longum from India.