A fungal disease that devastates soybean crops has made it to the continental U.S. It’s called Asian soybean rust and Iowa State University professor Greg Tylka is an expert. He says soybean rust was probably carried to Louisiana — where it was just found this week — by the fierce hurricanes that struck the southern U.S. this summer and fall. Tylka says even before the hurricane season, rust had been found in Columbia — a significant development because it marked the first time the disease had been found in our hemisphere north of the equator. He says the spores land on soybean leaves, they shoot out a little tube that goes into the leaf and then the fungus starts to feed itself on the plant tissue. The leaves first turn yellow, then brown — or a rust color. Tylka says as the fungus feeds itself on the soybean plant, it produces more spores that will then be released and spread on the wind to other plants. Tylka says the discovery of soybean rust doesn’t mean Iowa farmers need to take dramatic action or worry that yields will be dramatically reduced. He says there’s a very good chance the spores will make it to Iowa in the 2005 growing season, but there’s no way to predict when it will get here. Tylka says the most likely scenario is that Asian soybean rust will show up in Iowa farm fields late in the growing season, and that means it’ll cause less damage to the plants — and ultimately to yields. Tylka says the second unknown is which weather conditions are going to exist when those spores make it to Iowa, and weather plays a significant role in how the spores develop. He says if the weather in the growing season is hot and dry, soybean rust won’t have nearly the impact that it will if the growing season is wet with moderate temperatures. The Iowa Soybean Promotion Board has just given Iowa State University half-a-million dollars over three years to help pay the salaries of three scientists who’ll search for answers to the soybean rust problem.
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