For much of the state of Illinois, planting has been delayed due to seemingly perpetual rain and wet conditions. Hopefully there will be a window of opportunity soon to get back in the fields and continue, or in many cases begin field work and planting. As the calendar keeps progressing it will be tempting to complete fieldwork and planting in as little time as possible and in less than ideal conditions. Don’t forget that conditions at planting will play a major role in maximizing yields for both corn and soybeans from that point on.
Tillage and burndown herbicides
In a suppressed planting window, growers may decide to reduce or eliminate tillage passes and go no-till. Burndown herbicides are essential to the “Start Clean Stay Clean” idea. Identify the weed species present at the time of application to ensure a quality herbicide program. Make sure the herbicides you use are effective on the weeds you are targeting. Waterhemp will begin to emerge soon and is resistant to PPOs in much of the state. Also pay attention to planting restrictions. While growth regulators like 2,4-D and dicamba are highly effective, they require time between application and planting unless you are using seed tolerant to the respective herbicide traits. In minimum tillage situations my experience tells me to spray first. Allow at least 24 hours and then make the tillage pass. Failing to follow this routine will damage the weed before the herbicide works and result in a tillage escape.
Soybean maturity decisions
As planting dates reach mid-late May, questions commonly arise about shortening the maturity of the crop to ensure timely harvest. Soybeans do not mature by growing degree units (GDUs), but rather are photoperiod sensitive. Regardless of maturity, soybeans will typically all begin flowering around the longest day of the year. From this point forward, the maturity of the soybean dictates when it will ripen. Therefore, planting date normally has very little to do with when the soybean will be ready to harvest. Longer maturity soybeans have more days to set flowers, pods and seeds and typically yield higher, so at this point I would not recommend shortening your maturity. Very late planting dates (i.e. mid-late June), however, will cause a slight delay in harvest, which is why I recommend shortening up the maturity of your soybean variety by 0.5 maturity group if you are planting in June.
Patience is a virtue, but not something easy to practice this year. It’s tempting to push the limits and get in the field a day or two before conditions are ideal. Unfortunately, planting into cool and wet soil or even warm and wet soils can have detrimental effects on emergence. Soybeans may lay underground and rot in unfavorable soil environments. Fungicide seed treatments are highly recommended to help combat this issue. Soil crusting can prevent soybeans from being able to push through and emerge. Slow growing conditions early will make soybeans more susceptible to seedling diseases. All these things can lead to reduced and uneven stands, replanting and yield decreases.
When you do get the opportunity to get back into the fields, remember that the decisions you make early can have lasting effects through the season. Although a lot of research suggests early planted soybeans tend to yield higher, it’s important not to get in so much of a hurry that you jeopardize the rest of the season. And above all, please stay safe