Weather across most of Georgia, hot with better-than-even chance of rain, remains perfect for development and spread of fungal diseases in our row crops.
Southern corn rust arrived very late, but is spread across the Coastal Plain of the state. Southern corn leaf blight and northern corn leaf have been much more problematic this year.
CORN ISSUE OF MOST CONCERN NOW: Ear rots and mycotoxins (aflatoxin and fumonosins) Please refer back to e-mail from Dr. Noland about harvest and management of mycotoxins.
SOYBEAN RUST still only found in kudzu in Appling, Decatur and Grady Counties, though it has likely spread. Remember that critical times to protect the soybean crop are between first bloom (R1) and full-seed (R6) growth stages.
COTTON: Target Spot is here and across the Coastal Plain. Not every grower will benefit from protecting the crop with a fungicide; however every grower SHOULD be aware of the potential for loss and the opportunity to protect the crop. Considerations for protecting the crop should be made from the first week of bloom through the sixth week of bloom. Growers are encouraged to scout their fields for early detection of the disease; conditions are perfect now. When defoliation of the crop is greater than 25% or so, it is not clear a fungicide will help any more.
AREAOLATE MILDEW of cotton (looks a lot like a powdery mildew) is reportedly back in some cotton as far west as Colquitt County. Normally areolate mildew comes in late and does not cause a problem as far as yield goes; however if the diseases develops early, premature defoliation could be a problem. If areolate mildew develops well before intended defoliation timings, fungicides (same as used for target spot) could be helpful, though WE HAVE VERY LITTLE DATA TO SUPPORT that recommendation.
PEANUT: Conditions are PERFECT for white mold and leaf spot now in the peanut crop. Growers are strongly encouraged to stay on a timely fungicide program.
NO PROGRAM WILL KEEP ALL WHITE MOLD OUT OF A FIELD. Individual affected plants are going to happen. A good program keeps individual hits of white mold from turning into 10-foot runs of wilted plants.