Fusarium head scab of wheat (Fusarium graminearum Schwabe)

Abstract

Scab or head blight of wheat, caused by the fungus Fusarium graminearum Schwabe, was first described in 1891 by Arthur in the United States (2); it was later reported in Japan in 1902. In Mexico the disease was detected in 1977 in the Altos region in the State of Jalisco, although the specific pathogen species was not identified (19). At present, scab of wheat, also known as head blight, is prevalent in warm, humid regions throughout the world, e.g., north central Europe, Asia, and, particularly, China and Japan, where the disease is reported to be endemic. It has also been detected in the coastal region of North Africa, northern USA and southern Canada, as well as in the Southern Cone of South America, specifically Brazil,* Argentina,* Paraguay, and Uruguay (2, 12, 15, 25,41,50,59). Up to now in Mexico scab has generally been restricted to areas where wheat is grown under rainfed conditions, such as the States of Jalisco, Michoacan, Mexico, Tlaxcala, and Hidalgo. Total affected area is about 170,000 ha (Figure 1) (21). However, the disease is not found exclusively in rainfed areas and has been reported on irrigated summer-sown wheat in the Bajio region in Guanajuato, although this type of cropping is very sporadic