The cool and wetter weather earlier in the month has delayed some soybean planting into June. In addition, some cotton growers have switched to soybean due to the same reason. The question that came to me often this week was “Should I increase my seeding rate?”
In general, our research has not found a dramatic yield response to more seed per acre until mid-June. This largely reflects the lack of decrease in yield due to late planting dates until about the same time. If planted by the first week of June, the soybean usually has time to build a canopy great enough to capture most of the light by flowering, and does not need the extra plants.
However, I usually recommend that you begin increasing seeding rates by about 20,000 seed per week beginning the first of June.
Therefore, I would suggest the following:
This week (June 1-6): 120,000 – 140,000 seed/acre
June 7-13: 140,000-160,000 seed/acre
June 14-20: 160,000-180,000 seed/acre
June 21-27: 180,000-220,000 seed/acre
On your better soils or with later maturing varieties, use the lower seeding rate. On your less-productive soils or with earlier varieties, use the higher rate. This will insure that you you have enough leaf area to maximize the yield for those planting date.