Relationship of meteorological variables and inoculation techniques conducive for loose smut of wheat devleopment

Abstract

Ustilago tritici, a seed borne pathogen, remains dormant in seed embryo and causes loose smut disease. The present study was conducted to evaluate two inoculation methods i.e., dip inoculation and syringe inoculation to find out the better method for efficient and reproducible assessment of disease severity, disease incidence and screening of resistant wheat germplasm. Syringe inoculation was found to be better for the inoculation of heads with higher disease incidence than dip inoculation method. Twenty-seven lines were tested for their resistance against loose smut. Two lines were moderately resistant, nineteen lines susceptible and three lines were highly susceptible. Environmental conditions play an integral role in the development of loose smut disease. The relationship of temperature, humidity and rainfall with loose smut development was studied. An average temperature of 23-27 °C, relative humidity 60-90% and rainfall 0.02-1 mm rainfall were statistically most conducive for disease development. The correlation of environmental factors significantly influenced the disease development.