ASIAN SOYBEAN RUST, Phakospora pachyrhizi

Soybean rust is a serious disease of legumes causing significant crop losses in other parts of the world. The rust is caused by two fungal species, Phakopsora meibomiae and P. pachyrhizi that spread easily by windborne spores. The more aggressive Asian soybean rust ( P. pachyrhizi ) had been confined to Africa, Asia, Australia, South America, and Hawaii until 2004, when it was discovered in Louisiana. The current U.S. distribution for soybean rust consists of 9 southeastern states.

Asian soybean rust is capable of infecting over 90 species of legumes. The full host range of both rust species have not been clearly identified, although the broad host range increases the likelihood that soybean rust will survive and over winter in the southern U.S. It is unlikely that these Phakopsora spores can over winter in Maine.

The most common symptoms of soybean rust are tan to brown pustules on undersides of leaves, petioles, pods and stems. Infected leaflets may show a yellow mosaic pattern and leaves may drop prematurely.

Because soybean rust is spread easily by wind, there is some concern as to whether the previous hurricanes hitting the gulf coast will have spread soybean rust to other parts of the country. To read about the potential for soybean rust to spread to other states due to the recent hurricane activity, go to North American Plant Disease Forecast Center.

For more information go to these sites:

American Soybean Association
U.S. Department of Agriculture
USDA-APHIS-PPQ Pest Alert

If you suspect suspect Soybean Rust on your crop please notify the Maine Department of Agriculture (207) 287-3891.

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ASIAN SOYBEAN RUST, Phakospora pachyrhizi

For more information go to these sites: