Fusarium Wilt of Chrysanthemum – Problems and Prospects

Chrysanthemum flower production is adversely affected by many bacterial, fungal and viral diseases.Wilt caused by Fusarium oxysporum f. sp.chrysanthemi is one of the most serious diseases and causes severe yield losses.The pathogen enters the plant, multiply and blocks the vascular system with or without involvement of toxins and enzymes.Multiplication medium, pH and temperature plays significant role on the growth and sporulation of Fusarium oxysporum.Moderate temperatures, high humidity, availability of plant nutrients in soil encourage rapid disease development.High inoculum density causes greater disease incidence, hasty disease advancement and low flower yield.Degree of symptom development is related with the cultivar resistance and susceptibility.Plant extracts, polar and non-polar fractions, their pure compounds, and essential oils have potential antimicrobial activity against Fusarium oxysporum.The active phyto-constituents responsible for antifungal properties are low molecular weight phenols, tannins and lignin.Trichoderma and other phyto-pathogenic fungi are known to diminish wilt disease caused by Fusarium oxysporum f. sp.chrysanthemi.Myco-parasitism, antibiosis, nutrient competition and starvation, siderophore production and induction of systemic resistance are the major mechanism employed by Trichoderma for controlling pathogens.The present paper is intended to discuss the aspects of epidemiology, pathogenesis and biological control measures of Fusarium oxysporum with emphasis on Chrysanthemum wilt.