A scientific review released recently identifies “significant” risks of accidentally introducing Asian soybean rust disease into the United States, according to the American Soybean Association.

The commodity group says the USDA publication, “Status of Scientific Evidence on Risks Associated with the Introduction into the Continental United States of Phakopsora pachyrhizi with Imported Soybean Grain, Seed and Meal,” provides a concise summary of the current data related to Asian soybean rust disease.

“APHIS' scientific review is useful in examining the state of existing knowledge about soybean rust, and it clearly demonstrates the need for additional information in several key areas to determine whether commodity soybeans can be imported safely from rust-infected countries,” said association chairman Dwain Ford, a soybean producer from Kinmundy, Ill. “We believe these questions need to be answered, based on the best-available science, before a pest risk analysis for soybeans and procedures governing imports of commodity soybeans from rust-infected countries are issued by USDA.”

Since rust spores can survive for extended but yet unknown periods of time in vegetative material or on the surface of soybeans, the period of time rust spores remain viable in light, humidity, and other conditions in which soybeans typically are stored in rust-infected countries is one of the key questions that must be answered, the group says. Previous studies have indicated that rust spores can remain viable for 45 days or more.

Soybean industry officials also question the potential for re-contamination during the various transfer and loading stages of soybean exports.

While questions remain unanswered about whether soybeans can be imported safely from rust-infected countries, APHIS' scientific review documents that rust spores are destroyed by the heat and other processes used to convert whole soybeans into soybean meal and soybean oil.

Because of that, the American Soybean Association is urging that any pest risk analysis or import protocols governing soybean meal imports from rust-infected countries require that any foreign material intended to be added back into soy meal undergo heat treatment to destroy rust spores. In addition, the group believes that finished soybean meal must be handled in such a manner as to prevent contamination with viable rust spores.

USDA's scientific review documents that soybean rust is not a disease that infects the seed or seed coat, but rather is present in vegetative material or potentially on the outer surface of seeds. For this reason, the soybean commodity group wants to see import protocols require that soybean seed be clean and free of vegetative material. It also wants a requirement that seed from rust-infected countries be treated with a fungicide.

Soybean rust (P. pachyrhizi) is listed as a select biological agent that is under official control to prevent its introduction into the continental United States and is therefore considered a quarantine pest subject to phytosanitary measures. The USDA acknowledges that an updated, national, comprehensive economic analysis of a major U.S. infestation of soybean rust will require a much more involved analysis than was presented in the report.

“The American Soybean Association continues to examine the scientific review in detail,” Ford says. “Our goal is to protect the U.S. soybean industry from the accidental introduction of soybean rust via imports, while insuring that decisions are based on science. Decisions or import restrictions that aren't science-based could come back to hurt us as a global soy exporter, or could serve to choke-off domestic livestock demand. Neither is in the interests of U.S. soybean growers.

“Based on APHIS' scientific review, soybean meal and planting seed can be imported safely if handled under the proper protocols,” he says. “We urge APHIS to make our recommendations part of any import protocols governing soybean meal and soybean planting seed imports, so that the U.S. soy industry is safeguarded from the accidental introduction of soybean rust. The American Soybean Association's position on soybean imports, however, is that key scientific questions must be answered before any soybean import protocol is issued by APHIS, and before any potential commodity soybean imports from rust-affected countries are contemplated.”