Field Notes from Kip Cullers

Question: How do you get soybeans to stand at your high populations?

Kip: Keeping soybeans standing is one of our biggest challenges. We think that heavy pod load and high plant height are the two biggest contributors to lodging potential. Growing soybean in our low-stress system contributes to both. In our contest plots that we expect to be the highest yielding, we are seeing pod loads of about 60-100 per plant on plants 5-6 feet tall. Our plant population of ~200,000 per acre may add to lodging potential somewhat. We are trying to figure out how to keep our plants shorter (shorter internodes) or possibly to develop more branching to reduce the tendency to lodge. One day last week we had rains of 5 to 10 inches, depending on which rain gauge you looked at. This pounded down the bean canopy even further.

Question: What, in general, can I do to improve yield of 50-65 per acre? I spray glysophate twice, once early and again during the second flush of weeds. I don't use fungicide or insecticide.

Kip: In general, our main approach to growing high-yielding soybeans is to provide a season-long, low-stress environment for the crop. This means supplying ample nutrients pre-plant and supplementing with N and micronutrients as needed throughout the season. It also means maintaining plant health with repeated (if needed) sprays of fungicides and insecticides plus frequent irrigations to cool the crop and supply adequate moisture for root uptake. With larger fields or less flexible irrigation systems it may not be possible to irrigate as frequently as we do during really hot weather. During a recent stretch of 100+ degree weather, we applied 0.3 inches every morning. Then in the afternoon, we applied another 0.1 inch as we brought the pivot back into position for the following day. We are also investigating new biological seed treatments like Optimize to see if they will give us a yield boost.

Question: Do you no-till your beans into corn stalks or are you min-till? And are you using any cover crops?

Kip: We do not really do much minimum tillage because we have to incorporate poultry litter in the fall prior to each crop. There is almost no residue left on the surface when we plant our soybeans. We have not been using any cover crops for either corn or beans.

Question: What are the maturities of the soybeans you plant? Do you plant any group 5 or group 6 soybeans? I have never seen that many beans on a plant.

Kip: We plant mostly late group 4 soybeans. However, we have one patch of a mid-group 3 and we have been testing an early group 5 maturity soybean this year as well.

Question: Do you use anything for white mold control? With the kind of population you're using, I would have been worried about white mold control if conditions would have gotten wet.

Kip: We have had experience with white mold from growing green beans where lush rapid growth is also encouraged. Our daily irrigations do make white mold a potential concern. We also hear that Asian soybean rust is all around us in neighboring counties. We use aerially applied foliar fungicides, as needed, during the season to control all leaf diseases in our soybean contest plots. We want to keep them as clean as possible. So far, plant health has been excellent and we are now deciding what we need to do to get the crop to mature and dry down for a timely harvest.