Nature and storms do more over the long run to affect agriculture than anything else. It seems that most of our ag scientists believe that the hurricanes of the recent summer are at fault for the appearance of Asian soybean rust in the United States.
Ivan received the most blame. A recent quote from Erik Stromberg of the Plant Pathology, Physiology and Weed Science Department at Virginia Polytechnic Institution describes the situation: “I've watched soybean rust spread through South America very quickly. It was in Bolivia in 2003, and it moved into Columbia in 2004. In October, as I was watching the satellite pictures of Hurricane Ivan on my computer, I noticed the moisture streaming off from over Columbia and feeding into Ivan, and I said, ‘My God, this thing is going to be here soon, and we'll be dealing with it this time next year.’
“I thought it might reach the Caribbean basin but it went much further, into Louisiana. One of the very disturbing things is finding it in northeast Arkansas, as well, because it means those spores traveled a very long way very quickly.”
Already the disease has been found in most of our southern states — Alabama, Arkansas, Florida, Georgia, Mississippi, Missouri, South Carolina and Tennessee.
Pesticide Net says that “The disease has been present throughout Asia and Australia for decades. During the 1990s, it emerged, and became a serious problem, in South America and South Africa. Experts have said all along that it was only a question of ‘when,’ not ‘if,’ soybean rust reached the continental United States via wind-blown spores, imported soybean meal, bioterrorism, or some other vehicle.”
Stromberg considers equally, perhaps even more disturbing, the potential that current strains will mutate into even hardier strains which can withstand the cold of our Midwest — the primary soybean growing area of the U. S.
All current strains are at this point susceptible to correctly applied, registered fungicides. Adequate supplies of all are available in the U.S. and can be used either under FIFRA Section 18 emergency exemption or are already directly registered for use on soybeans. Syngenta and BASF currently hold most registrations.
Extension services all do not recommend preemptive spraying yet in the Midwest, but to target infestation only. Close scouting will be required.