Field Crops News

Beating Wheat Scab

Fusarium head blight, also known as wheat scab, is increasing as a threat to sustainable wheat production. In North Dakota, South Dakota and Minnesota yield and grain quality losses amounted to nearly $1 billion in 1993 and ranged from $200 million to $400 million annually since then. In Ohio, Michigan, Indiana and Illinois, losses from wheat scab exceeded $300 million in 1995 and 1996. Food safety is also an issue with scab, as products made from the infected grain could be contaminated by a mold by-product, a poison known as vomitoxin. All of the pastry wheat varieties are susceptible to scab, which is most severe when wet weather occurs while the crop flowers in late May to early June.

Cornell University (New York) researchers are collaborating with colleagues at the Brazilian Wheat Research Center (EMBRAPA Trigo) in Passo Fundo, Brazil, to examine the potential for using naturally occurring microorganisms to fight fungal infections of wheat and corn plants in both the United States and Brazil. Brazilian scientists have isolated thousands of strains of bacteria and yeast growing naturally on plant leaves, roots and soil that exhibit anti-fungal activity. The researchers are assessing some promising microbial strains in greenhouse experiments for their ability to control a range of diseases.

When wheat heads were treated with bioprotectant bacteria before they were sprayed with Fusarium spores the plants showed fewer diseased grains with significantly lower levels of contamination by vomitoxin than did nonprotected plants.

Application of the bio-protectant strains to cereal crop seeds promoted the germination of seeds in soil to the same extent as treatment with chemical fungicides. Initial tests in Brazil indicate that the biocontrol strains are also effective in controlling disease under field conditions.

Source:

Friedlander, B. P. 1997. Researchers study biological control for wheat crop threat. Cornell Chronicle Vol. 28, Number 42, August 14, 1997


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