For the past three years we have had excellent field conditions for early and timely corn and soybean planting in Minnesota. Conditions are such now that this season will be later, but still could be an "average" or "normal" planting season, especially for soybeans. For a reminder of what's normal, the average corn planting date is May 6; it's May 18 for soybeans. If field-drying conditions exist for the next several days, both crops could be planted in the normal timeframe.
Questions now are when to change maturities of both corn and soybeans. We recommend "staying the course" with the seed choices you have made until May 25. After May 25, we recommend the maturities given in Table 1 for corn:
Table 1. Recommended corn hybrid maturities for late planting in Minnesota
|Planting date||Relative maturity units earlier than full season|
|Prior to May 25||Plant the normal seed choices planned for the season|
|May 25 - May 31||Plant hybrids with maturities 5 to 7 RM units earlier|
|June 1 - 10||Plant hybrids with maturities 8 - 15 RM units earlier|
|June 11-15||Plant hybrids with maturities 15 or more RM units earlier|
For soybeans, we recommend the maturities given in Table 2.
Table 2. Recommended soybean maturities for late planting in Minnesota
|Planting Date||Relative maturity units earlier than full season|
|Prior to June 10||Plant the varieties planned for the season|
|June 11-20||Plant varieties with a maturity rating of 0.5 units earlier|
|June 20-30||Plant varieties with a maturity rating of 1 unit earlier|
More discussion for late planting of both corn and soybeans is given in The soybean growers field guide for evaluating crop damage and replant options and The corn growers field guide for evaluating crop damage and replant options.
Minnesota corn growers have been planting hybrids that are 5 relative maturity earlier than we believe is full season for the area. This gives some flexibility for planting those maturities later in the season. Further, we believe growers are best served by planting the hybrid and soybean variety choices they have made because changing seed choices may change the maturities, but the chances are not good of getting the best yielding hybrids and soybean varieties in earlier maturities. Seed of those hybrids and varieties has already been sold and delivered to growers.
We've also had some early maturing seasons with good field drying conditions that has resulted in lower corn grain drying costs. Later planting usually means later maturity dates with less calendar time for field drying, so drying costs may be higher this year. Might be a good plan to forward price LP gas for drying if the price looks good during the summer.