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

Fusariumis considered as a devastating fungal menace of the most prevalent fungus on maize, particularly in USA, Europe, Africa, Asia and Australia. It causes Fusarium stalkrot 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 stalkrot is not effective. A number of quantitative trait loci have been identified which will help to expedite breeding program against Fusarium stalkrot. Moreover, various chemical and biological control methods have been developed, but major emphasis is on development of maize cultivars with genetic resistance to Fusarium stalkrot 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 StalkRot (FSR), Rajasthan Downy mildew, Maydis leaf blight, Banded leaf and sheath blight, Curvularia leaf spot, Brown stripe Downy mildewand Turcicum leaf blightare major diseases of maize. Among these diseases of maize Fusarium stalkrot of maize is caused by Fusariumverticillioides (Saccardo) Nirenberg ( = Fusariummoniliforme (Sheldon), was first reported from United States of America by Pammel in 1914 as a serious root and stalkdiseases. Later Valleau (1920) indicated that Fusariummoniliforme was a primary cause of root rotand stalkrot 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 stalkrot was first reported from Mount Abu, Rajasthan (Arya and Jain, 1964). Fusarium stalkrot was observed in the plant age group of 55 to 65 days which coincides with tassellingand silking and immediately followed grain formation stage. At these stages the stem reserves are depleted and most of the carbohydrates are