More than half of soybeans planted in the U.S. have reached the reproductive stages. According to the USDA National Agricultural Statistics Service, as of July 27, 76 percent of soybeans are in bloom and 43 percent are achieving pod set. Here are a few things to keep in mind to better manage your soybeans through this important time.
Flowering to Full Pod Set (R1–R4)
The reproductive stage is triggered by flowering. This process usually starts toward the end of June, as we get past the longest day of the year. By now, many growers are likely well into the R3 (beginning pod) stage. Growers should already be done with their herbicide applications. In fact, most chemical labels note that applications need to be completed by R2. This allows the plants to produce as many blooms as possible. If you spray after R2, you risk damaging the flowers and early-developing pods. Completing spraying applications by this time also helps prevent herbicide carryover for the next growing season.
If you’re experiencing any issues with white mold, anthracnose, SDS and foliar diseases such as frogeye leafspot, cercospora leaf blight or brown spot, the best time to apply fungicides during the reproductive stages in soybeans is R1–R4. Now is a good time to safely apply fungicide, up until full pod set, for the best yield potential. After this stage, it may be too late.
Growers experiencing problems with bean leaf beetles, aphids or grasshoppers should also consider spraying an insecticide around this timeframe.
Beginning Seed to Full Seed (R5–R6)
We’re nearing one of the most important stages in the reproductive cycle, which typically occurs in August — seed set. Mother Nature is a crucial here as timely rains can encourage the necessary nutrient uptake to ensure good pod fill.
While we await to see what the weather will be, it’s also a good opportunity to spray for aphids. Experts from Iowa State University note that foliar insecticides can help fend off aphids. That said, to achieve maximum effectiveness, it’s recommended that application needs to be done prior to full seed set.
Unfortunately, if you experience any issues or weather events that could damage soybean plants during this timeframe, it’s likely too late to do anything to prevent yield loss.
Beginning to Full Maturity (R7–R8)
Plants will likely begin dropping leaves during this stage, and pods and plants will begin to brown or mature in color. Luckily, at this point, you’ve reached a point where yield loss due to stressors decreases. However, you could experience lodging.
Once your fields have reached full maturity, you’ll find that at least 95 percent of pods have browned or matured in color. At this point, it’s time to start thinking about harvest. Experts from the University of Wisconsin recommend five to 10 days of drying weather to achieve less than 15 percent moisture before harvest. Timeliness to harvest soybeans is crucial. Delayed harvest may result in shatter loss, split beans or loss in pod weight.
A good soybean crop depends on a solid management plan up front. Stine has a number of excellent soybean varieties in a full range of maturities and trait options so that you can select the right fit for your field. We also have a line of Stine XP soybean seed treatments to help protect your seed from early diseases and insects. Combined with a good fertility program and proper management of the crop in-season, you’ll be in a great position to achieve maximum yield potential. If you have any questions regarding management of your soybean crop, especially during the important reproductive stages, please consult with your local Stine agronomist or sales rep.