Plant Disease Research

Myrothecium roridum tode ex Fr. causes severe leaf spot disease of poplar. Four new hosts of this pathogen were recorded in Punjab namely shisham (Dalbergia sissoo roxb. ex Dc), mulberry (Morus alba L.), paraspippal (Thespesia populnea (L.) Sol. ex correa) and dodak (Euphorbia hirta L.), which is a common weed of forest nurseries. Disease incidence on poplar, mulberry, shisham and paraspipal varied from 7–100, 5–60, 5–80 and 5–40 per cent with severity of up to 50, 30, 35 and 20 per cent, respectively. The disease was prevalent on poplar and mulberry in sub-montanous and central plain region whereas on shisham, it was present all over Punjab including Southern arid plain region. This fungus produces a toxic metabolite in the culture and the necrosis of the leaf tissue starts 8 hours after inoculations. Isolates of M. roridum from mulberry, paraspipal, shisham and dodak produced symptoms on poplar and cotton leaves within 6 to 7 days. Complete mycelial inhibition of M. roridum was recorded with bavistin 50wP at a concentration of 10 μg/ml under in vitro conditions.