Fusarium stalk rot: a major threat to maize production in India

Fusarium is considered as a devastating fungal menace of the most prevalent fungus on maize, particularly in USA, Europe, Africa, Asia and Australia. It causes Fusarium stalk rot on plants, which is considered as major threat to production of maize, accompanied by small losses to total wipeout of the crop. This disease is more prevalent in area where water stress occurs after flowering stage of the crop. Owing to its soil borne infection pathway, fungicidal control of Fusarium stalk rot is not effective. A number of quantitative trait loci have been identified which will help to expedite breeding program against Fusarium stalk rot. Moreover, various chemical and biological control methods have been developed, but major emphasis is on development of maize cultivars with genetic resistance to Fusarium stalk rot for environment friendly control of the disease. Sustainable maize cultivatio n is continuously challenged by diseases that cause quantitative and qualitative losses in yield. Apart from abiotic stresses a number of fungal, viral and bacterial pathogens have been reported causing different diseases in maize (Payak and Sharma, 1980). Fusarium Stalk Rot (FSR), Rajasthan Downy mildew, Maydis leaf blight, Banded leaf and sheath blight, Curvularia leaf spot, Brown stripe Downy mildew and Turcicum leaf blight are major diseases of maize. Among these diseases of maize Fusarium stalk rot of maize is caused by Fusarium verticillioides (Saccardo) Nirenberg ( = Fusarium moniliforme (Sheldon), was first reported from United States of America by Pammel in 1914 as a serious root and stalk diseases. Later Valleau (1920) indicated that Fusarium moniliforme was a primary cause of root rot and stalk rot of maize. Subsequently this disease has also been reported from several countries like Canada (Conner, 1941), U.K. (Butler, 1947), Hungary (Podhradszky, 1956), North America (Kucharek and Kommedahl, 1966), Russia (Ivaschenko, 1989) and China (Wu et al., 1973). In India Fusarium stalk rot was first reported from Mount Abu, Rajasthan (Arya and Jain, 1964). Fusarium stalk rot was observed in the plant age group of 55 to 65 days which coincides with tasselling and silking and immediately followed grain formation stage. At these stages the stem reserves are depleted and most of the carbohydrates are