Dr. Bob Kemerait, University of Georgia ExtensionPlant Pathologist,this week filed the following update on disease pressure in our major field crops.
CORN: As of July 25, Southern corn rust has been identified at very low levels in Pierce County (Sentinel plots), Toombs County (Viadalia REC), and Mitchell County (Stripling Irrigation Park). Recent rains have made the environment more favorable for development and spread of this disease. I expect that southern rust will continue to spread. Dr. Dewey Lee, UGA Extension agronomist, and I are fairly confident that corn that has reached the dough stage should be safe from rust now. Growers with late planted corn should be aware that the disease is developing accross the southern part of the state.
SOYBEANS: As of yesterday, Asian soybean rust has NOT yet been found in Georgia, though I expect it soon. It was found on July 12 in Quincy, Florida and I expect to find it in south Georgia any time now. It was found over the past couple of days in Louisiana. Growers should be prepared to protect their soybeans in southwestern Georgia once we see the disease continue to move.
PEANUTS: Although we have had few reports of outbreaks of white mold in commercial fields, white mold remains active in field plots; we have entered that part of the season when growers should be very attentive to disease management; especailly white mold.
COTTON: We have had several reports of “Corynespora leaf spot” on cotton in south Georgia to date. Growers who have found this disease in their crop should consider whether or not treating the field, or a partof the field, with a fungicide is of interest to them. If they have questions about their risk (I believe highest risk is in irrigated fields, short rotations, and where the disease was found last year). Finally, Fusarium wilt has been found now in Colquitt, Tift, and Berrien Counties on cotton.