Double crop soybeans in WI may be worth it
The biggest question on inputs that we have not addressed yet is seed treatments. I want to say right up front that I have little-to-no data in our conditions about the need for seed treatments in a WI doublecrop soybean system so I can only put forward my thought process and rationale.
1. Warm and unsaturated soil conditions will expedite soybean emergence and minimize pathogens so the need for a fungicide seed treatment will be greatly reduced.
2. Seed applied fungicides and insecticides are often partnered so if you do decide to use an insecticide a fungicide will likely be part of the mix.
3. Soybeans will be emerging as soybean aphid populations are increasing.
4. Seed applied insecticides have a ~35 day efficacy window (check individual product specs) which will provide protection into early August before any scouting is required.
5. Aphid feeding can be more injurious under water stress which these beans will likely be under so…..sans data an insecticide seed treatment may be warranted.
Lastly and undoubtedly the most important factor for double crop soybean profitability will be the environment. The two major environmental events to consider with double crop soybean are establishment and frost. It is likely that soil moisture will be depleted following a winter wheat crop and rainfall patterns in July are often spotty at best, therefore crop emergence and establishment may greatly be delayed if we need to wait on adequate moisture. Therefore no-tilling soybeans to conserve soil moisture and planting to moisture (assuming moisture is 2 inches or less) is important. If there is not adequate soil moisture and there is no rain in the forecast don’t plant. The second and perhaps more important environmental event is frost prior to physiological maturity. Individual soybeans that are not mature and are subjected to a significant frost event will remain green even if weather conditions warm.
Even if frost does not occur, a grower will likely harvest some green beans. The implications of these green beans are storage problems as well as significant dockage at the elevator. Please see Effect of Freezing on Soybean Seed Yield and Composition for more information.
2012 has already been a unique and challenging year for WI growers but if the wheat continues to progress at its current pace and we catch timely rains a real potential for profiting on double crop soybeans may exist.