Field Notes from Kip Cullers

Question: With your high populations and thick canopy in soybeans, how do you manage white mold infestations? Has this disease been a problem in the past and what is your best estimate on yield loss due to white mold? Also, with exception to your contest fields, what is your desired plant population for commercial fields in soybeans and corn?

Kip: White mold is a concern of ours on soybeans and we have seen this disease in past crops of our green beans here. With foliar fungicide sprays, we have been able to keep white mold under control in all of our bean crops. When multiple applications are needed in the same season, we rotate active ingredients to avoid the disease becoming resistant. Our plant populations vary depending on yield potential which for us is dictated by irrigation use and soil type (depth of the rooting zone). Our non-contest plant populations will range from 32,000 to 44,000 for corn and 200,000 to 250,000 for soybean. However, every year we continue to conduct on-farm tests of various seeding rates and row spacing, so our optimum seeding rate targets might change from year to year.

Question: I've heard you mention the use of vinegar to help keep plants shorter. At what rates do you apply it and at what stage? Does it work consistently? Very interesting concept.

Kip: We normally apply about 8 ounces of vinegar per acre through our pivot irrigation system several times per season. We think this helps keep soybean stem internode growth in check but we have not done any side X side checks to test this theory out. We think the mild acidity or some other property "shocks" the plant. Excessive vine growth was a major challenge this year, so we may need to rethink our vinegar strategy in terms of rate, number of applications or even using other growth inhibiting products.