DISEASES OF MAIZE IN SOUTH AND SOUTH-EAST ASIA - PROBLEMS AND PROGRESS

In Asia, maize ranks third after rice and wheat both in area and produ ction. In recent years, maize production has shown a steady increase w ithout much increase in area, but productivity has been low (2.8 t ha- 1). The major maize-producing countries in Asia are China, India, Indo nesia, Philippines, Thailand and Vietnam. Information embodied in this review pertains to the countries of South and South-East Asia. The ub iquitous incidence of diseases at the preharvest stage has been an imp ortant bottleneck in increasing production. The major diseases in the region are five downy mildews, four foliar, two pre-flowering and four post-flowering stalk rots, and leaf and sheath blight. Information on virus diseases, nematodes and postharvest microbial problems is also given. Information on distribution of diseases is provided. Concerted efforts involving regional and national programmes sponsored by the Ro ckefeller Foundation and the Centro Internacional de Mejoramiento de M aiz y Trigo have yielded good dividends, particularly in the case of d owny mildew diseases. The development and release of cultivars resista nt to downy mildew has been an important outcome of this cooperative r esearch. The use of disease management methods other than host resista nce has also been highlighted.