ACROSS MISSISSIPPI — There is no known soybean rust in Mississippi thanks to the cold winter that killed kudzu, a common rust host, across the state.
“This is the first year since soybean rust was initially detected in the U.S. that we have essentially started at zero in regards to soybean rust,” said Tom Allen, Mississippi State University (MSU) Extension plant pathologist at the Delta Research and Extension Center in Stoneville. “None of us truly knows what to expect of the progression of the disease this season.”
Extension Service soybean rust scouting team has planned this year’s battle against soybean rust, which begins with early detection.
Allen said 24 sentinel plots were planted throughout the state, with two along the Gulf Coast and others in counties bordering Arkansas, Louisiana and Alabama. These plots were planted by April 2.
Mississippi had significant rust in 2009 in many soybean fields, but only one field left untreated had excessive losses due to the disease. In the past, rust has generally come into the state on winds that have blown across the Gulf of Mexico and over a source of infection in Alabama, Florida or Louisiana. During the past two years, soybean rust has overwintered on kudzu, a rust host. However, this winter’s cold helped the rust battle.
“Winter temperatures killed kudzu all the way down to the Gulf Coast in Mississippi, Alabama, Florida and Louisiana,” Allen said. “There were reports in January of rust found on remaining kudzu in protected locations in Louisiana, but by February and March, the kudzu had succumbed to the cold temperatures across the South.”
On April 7, the only kudzu vine known to be infected with rust was destroyed. Allen said the vine was inside a dilapidated building in Mobile, Ala.