Here we are on 25 August. There is no doubt we will still be picking cotton and peanuts somewhere in Georgia two months from now, but you can readily feel anticipation for the start of harvest whenever you are with growers. As harvest approaches, keep the following in mind.
Consider cotton vulnerable to target spot until the sixth week of bloom and vulnerable to areolate mildew until within four weeks of anticipated defoliation. I cannot explain it, but I have seen beaucoup target spot this year and little areolate mildew, though there is some out there. Note that once a cotton crop reaches 25% or more defoliation to disease, there is likely little benefit from a fungicide application.
Consider soybeans vulnerable to rust (we have found none yet in Georgia), Cercospora leaf blight, and other diseases until R6 (full seed size) growth stage. However, significant defoliation prior to R6 can easily negate the benefit of subsequent fungicide applications.
Consider protecting peanuts from leaf spot and white mold to within two to three weeks of anticipated digging dates. Well-rotated fields with little disease might go four weeks without a fungicide, but I would advise against it as our hurricane wildcards could delay harvest u expectedly. For peanuts I do not generally recommend digging early no matter the level of tomato spotted wilt. Growers should be preparing to dig peanuts that are more than 50% defoliated to leaf spot or damaged by white mold. Leaving peanuts in the ground can increase grade, but can also add to digging losses of our most mature peanuts when disease prevails.
PHI stands for “pre-harvest interval” and is the legal limit where a fungicide (or any pesticide) can be applied to a crop. “Harvest Date” for corn, cotton, and soybeans is obvious. For peanuts I follow that “harvest date” is when they are picked and not when they are dug.
