The highly contagious soyabean rust disease was found in three more Florida counties, boosting to 12 the total number of counties in the state infected with the fungus, the US Agriculture Department said on Monday.
USDA said on its rust-monitoring Web site rust was found in a commercial soyabean field in Madison County near the Georgia border, and on kudzu in Alachua County in northern Florida.
The agency also said it was set to confirm that the fungus spread to Lee County in southwest Florida. USDA did not say what type of plant the disease was found on.
So far, the fungus has been found in four small soyabean-producing states - Alabama, Florida, Georgia and Mississippi - which accounted for about 2.5 percent of last year's record 3.1 billion bushel crop. The yield-cutting disease has been found in a total of 24 counties in the four states.
"We are recommending that growers in Florida consider spraying for Asian soyabean rust as their plants approach bloom," the Florida crop scout said. "We expect weather conditions will continue to be conducive for rapid disease development once a site is infected."
USDA Agriculture Secretary Mike Johanns said on Friday the chance of a widespread outbreak of soyabean rust involving the major soya-producing states of the Midwest was increasingly unlikely for 2005.
USDA said weather conditions were favourable for the development of soyabean rust during the next few days in the northern half of Florida, Alabama, Georgia, the Carolinas, eastern Tennessee and Kentucky, West Virginia, and the Mid-Atlantic states as far north as Pennsylvania.