Published on Monday, May 8, 2017
Many areas of Ohio turned dry towards the end of April and farmers were able to get their corn and soybeans into the ground at a good pace. In fact, the USDA projected that 42 percent of all corn and 14 percent of soybeans had been planted by April 30, 2017. Then…everything came to a screeching halt as frequent rainstorms have resulted in several inches of rain covering most of the state.
The corn acres that were fortunate enough to be planted prior to April 20 have emerged in most areas. Corn and soybeans planted after April 20 may or may not have emerged, leaving many wondering if they will come up at all.
We can’t truly evaluate our stands until we’ve had enough heat units or growing degree days (GDD) for emergence to occur. Corn, on average, takes approximately 110 GDD to emerge while soybeans take approximately 135 GDD. The number of GDDs can vary a little depending on genetics (some emerge quicker than others), residue (the more residue the slower the emergence), soil type, and planting depth. Based on these factors, corn can vary from 90 to 120 GDD while soybeans can vary from 90 to 145 GDD.
Based on your planting date and the forecasted temperatures, it could take up to three weeks for corn to emerge in some areas and even longer for soybeans. The chart below provides the projected number of days to emergence in different areas throughout Ohio based on different planting dates.
As the fields start to dry over the next week (hopefully), don’t be too quick to replant! Just because your crops may not have emerged yet, that could be because we have not accumulated enough heat units. Remember, emergence is based off of heat and not calendar date.
According to replant charts, a final stand of 20,000 plants/A. planted on April 25 still has 92 percent of optimum yield potential. A field planted on May 20 at 32,000 plants/A. has less projected yield (around 91 percent) than the reduced stand planted in April. Once your fields start to dry off, it would be best to plant all your other acres first before attempting to replant.
Here’s hoping for some dry weather in the next few weeks!
Author: Mark Apelt
Categories: Agronomy, Ohio
Tags: corn planting, Agronomy, Emergence, Ohio Agronomy, growing degree days, soybean planting, GDD, yield potential