Our traditional critical period for white mold fungicide control has characteristically begun around 60 DAP. Under years where weather conditions during earlier portions of the season are conducive to its development, we have seen benefits to including effective products during earlier application timings (e.g., 45 to 30 DAP). In the attached pictures, a seedling with mycelium of the white mold fungus can be seen. Also attached are slides from work we conducted looking at different fungicides for white mold management.
A question came up about whether or not application of land plaster would be recommended for runner fields where soil Ca test levels were in the 700 to 900 lb/A range. My response was that if there is irrigation and/or timely rains, depending on the runner cultivar it could be alright, but that can be a big "if" we would need to be comfortable with. We did one trial last year where we had about 890 lb/A soil preplant Ca with 06G and we did not have a yield loss in that test where we did not apply land plaster. That is one year and we are looking to repeat that test this year, but last year that test did receive timely rains during pod fill which helped with soil Ca availability. I like to err on the side of caution given the many variables and generally like to see (at least some) land plaster being applied (unless it is smaller runners [seed size 650/lb or less] on soil levels around 900 or above). In 2019, which was a stressful drought/hot year, a farmer nearby had 06G next to 297 in a field, and the 297 went Seg III whereas the 06G with its smaller pod size did not. I don't know what the baseline soil Ca levels were in that field, but the entire field did receive a standard rate of land plaster. I mention this as an example of how under certain weather conditions or growing seasons we can see differences among runner cultivars.
Dan Anco
Extension Peanut Specialist and Associate Professor
Department of Plant and Environmental Sciences
Clemson University – Edisto Research and Education Center
64 Research Road
Blackville, SC 29817
630-207-4926 cell