Physiological studies of Sclerotium rolfsii Sacc. causing collar rot of peppermint

Abstract

In vitro studies were conducted on the effect of temperature, pH levels, carbon, nitrogen and amino acids on the mycelial growth and biomass production of Sclerotium rofsii Sacc. causing collar rot of mint. The results reveal that the growth of S. rolfsii was maximum at 30°C which was reduced significantly below 20°C and above 35°C. Of the pH levels tested, acetic pH (5.0) produced maximum mycelial dry weight which was followed by exposing the pathogen to pH 6.0. Among the nine carbon sources tested, sucrose recorded the maximum mycelial growth and dry weight of S. rolfsii, while peptone was the best among the nitrogen sources and tryptophane and phenylalanine was the best amino acids on the mycelial growth and biomass production of S. rolfsii.

Key words: Sclerotium rolfsii, pH, mint, collar rot, nutritional studies, temperature.