Macrophomina phaseolina as causal agent for charcoal rot of sunflower

Macrophomina phaseolina has a wide host range and is responsible for causing losses on more than 500 cultivated and wild plant species. So far in Pakistan it has been reported to cause disease on 67 economic hosts including field crops, pulses, flowers and vegetable have been reported. Infection on sunflower was first reported from Sri Lanka in 1927 and in 1982 it was reported from sunflower field in Pakistan. The fungus is reported to be soil, seed and stubble borne. The fungus can survive for more than 10 months under dry soil conditions. The severity of the disease is directly related to the population of viable sclerotia in the soil. The pathogen generally affects the fibrovascular system of the roots and basal internodes. The parasitic fitness of a facultative soilborne pathogen before invading the host is linked with its ability to compete for its survival, utilization of organic sources and colonization in the host root rhizosphere by competing other microorganism in the vicinity.