Fusarium head scab: global status and future prospects

Abstract

Fusarium head scab of wheat was first reported in England around 1884; however, scab is generally more important in warm and humid areas. The various fusaria that cause scab are among the most variable and insidious fungi. Scab can cause significant yield and quality damage as well as toxicoses in animals and humans. Concerns about toxin-related illnesses caused by fusarium in animals and humans have increased in recent years. Part of the reason is the increase in the incidence of fusarium head scab in several areas of the world, namely, the United States and several countries in Europe. Its increase appears to be principally related to changes in weather and cropping patterns. Damage due to scab in the USA was estimated at more than one billion dollars in 1993 and 500 million in 1994. Epidemics in China are most common and severe in the Yangtze River Valley, and can affect more than 7 million hectares of wheat. It is estimated that in China up to 2.5 million tons of grain may be lost to scab in epidemic years. Diseases related to fusarial mycotoxins in humans have been reported in China, India, and Japan, whereas in animals they have been reported in numerous parts of the world. CIMMYT has been working to control this disease in wheat and maize for many years due to its importance in countries such as Argentina, Brazil, China, Paraguay, and Uruguay. Breeding for resistance in wheat over the last 15 years has only been partially successful due to the difficulty of incorporating sufficient levels of resistance. The progress that has been made owes a great deal to the shuttle breeding program between CIMMYT and China. As part of its efforts to control scab of wheat, CIMMYT sponsored two previous workshops related to scab control and the effects of Fusarium toxins. One was held in Uruguay in 1987 and focused on the control of scab, and the other in Mexico in 1989 and dealt with mycotoxins. To date, international funds to achieve control of fusarium scab have been modest in relation to its impact on health, grain yield, and quality. Due to this and its increase in many areas, it was thought overdue to organize a worldwide workshop with the following objectives: To obtain an update on the global situation of small grains scab and its impact on food-feed production and health; • To document relevant research and increase communication among researchers; To search for funds to increase research on sustainable control methods. The workshop was supported by CIMMYT and by the generosity of the government of Austria, specifically the Institute of Agrobiotechnology, Tulln. Participants came from Argentina, Austria, Canada, China, Hungary, Japan, Mexico, Russia, UK, Ukraine, Uruguay, USA, and CIMMYT, Mexico. It is hoped that the results of this workshop, and the integration of scientists' efforts worldwide, will focus attention on this disease, provide new data, and increase the support necessary to achieve economical and environmentally safe control.