Alternaria Solani - Economic Significance

Economic Significance

Early blight caused by A. solani is the most destructive disease of tomatoes in the tropical and subtropical regions. Each 1% increase in intensity can reduce yield by 1.36%, and complete crop failure can occur when the disease is most severe. Yield losses of up to 79% have been reported in the U.S., of which 20-40% is due to seedling losses (i.e., collar rot) in the field.

A. solani is also one of the most important foliar pathogens of potato. In the U.S., yield loss estimates attributed to foliar damage, which results in decreased tuber quality and yield reduction, can reach 20-30%. In storage, A. solani can cause dry rot of tubers and may also reduce storage length, which both of which diminish the quantity and quality of marketable tubers.

Because A. solani is one of numerous tomato/potato pathogens that are typically controlled with the same products, accurately estimating both the total economic loss and the total expenditure on fungicides for control of early blight is difficult. Best estimates suggest that total annual global expenditures on fungicide control of A. solani is approximately $77 million: $32 million for tomatoes and $45 million for potatoes.