By Benjamin Agyei And Maninder Singh
According to the USDA-NASS weekly crop progress report, only 23% of Michigan’s corn had reached physiological maturity by the last week of September, roughly half the level reported at the same time last year and the 5-year average. At maturity, corn kernels could have moisture content up to 35% based on planting date and hybrid relative maturity. In the coming weeks, more corn will reach physiological maturity, meaning that much of the state’s corn will dry down in October and November.
In previous Michigan State University Extension articles, the MSU cropping system agronomy team provided estimates covering the dry down period from early September to mid-November for several hybrid maturities and planting dates. Those estimates remain valid, and we encourage growers whose corn matured earlier to refer to them for dry down rates. However, given the statewide delay in corn maturation, the goal of this article is to provide growers with estimated weekly dry down rates from October through mid-November. These weekly estimates can help growers better anticipate changes in kernel moisture and make more informed decisions about harvest.
What dry down rates to expect?
Dry down rates were estimated using data from field trials conducted in Lansing, MI with multiple hybrid relative maturities (89-109 RM) and planting dates (late April to early June) across four growing seasons (2021-2024). Overall, kernel dry down rates will change significantly from the first week of October through mid-November. The highest dry down rate (averaged across multiple hybrid maturities and planting dates) is expected to be 0.58% per day during the first week of October (Table 1). In the second week of October, dry down rate could decline by approximately 38%, to 0.36% per day. Dry down rates are expected to continue declining during the third and fourth weeks of October, although the rate of decline will likely be smaller than the steep decline observed between the first and second weeks.
In the first week of November, dry down rates are expected to average 0.18% per day, approximately 28% lower than the rate during the final week of October. By the second week of November, dry down rates could decline further, averaging as low as 0.13% per day (Table 1).
It is important to emphasize that the dry down rates presented here are averaged across multiple hybrid relative maturities, planting dates, and growing seasons. As highlighted in our previous articles, dry down rates can vary depending on these factors. Therefore, growers may need to make small adjustments to these dry down estimates to reflect their specific hybrid maturity, planting date, and growing conditions. For example, early and mid-maturity hybrids planted early will mature earlier and could dry down at a higher rate than late maturity hybrids.
Source : msu.edu