Hotter temperatures and fewer clouds in the US Southeast and Mississippi River region will "bring less favourable" conditions for soyabean rust to spread during the next three days, the US Agriculture Department (USDA) said on Wednesday. Mississippi, Alabama, Georgia and South Carolina are expected to see temperatures rise into the 90s as the frequency of showers and thunderstorms declines.
"The combination of reduced cloudiness, high temperatures and little rainfall will continue to bring less favorable weather for disease development for the south-eastern states," the USDA said.
Similarly, temperatures are expected to be in the upper 90s and low 100s in northern Texas, Oklahoma, Missouri, Arkansas, and western Illinois with very little rainfall expected.
The change in the weather pattern across much of the United States is welcome news for growers who have seen soyabean rust spread following the departure of Hurricane Dennis, which agricultural researchers believe deposited spores from the highly contagious fungus.
The spread of soyabean rust has quickened in the past three days, with new cases confirmed in Georgia, Florida and Mississippi. The fungus also has been found in Alabama.
Warm weather, cloudy skies, high humidity and rain are all conditions that favour the spread of soyabean rust.
USDA also said Hurricane Emily, which hit northern Mexico and southern Texas with rain and wind, should not affect the spread of soyabean rust in the United States.
The soyabean fungus erupts in reddish-brown lesions on soya plants, causing them to drop their leaves and slashing production by as much as 80 percent.