Jarrod O. Miller, Extension Agronomist, jarrod@udel.edu
We have two earlier planted studies at our research station in Georgetown that are emerging from the ground. In our lime by planting timing study (sponsored by the Delaware Soybean Board), the first planting was done on April 9th, with emergence occurring 10 days later. Luckily outside of a few frost warnings, we haven’t had much to worry about.
In a study sponsored by the Maryland Grain Producers, corn was planted on April 16th and we have found the first true leaf starting to emerge from the coleoptile just beneath the soil surface. With temperatures warming up, we can probably expect to see corn emerge through the weekend.
So far, we have been lucky this year, and moderately early planting dates have not had to deal with saturated soils or freezing temperatures. In a recent update from Ohio State, they observed that the addition of moisture after planting (within 10 hours) reduced soybean emergence. They also observed that planting shallower (<1.5”) also reduced early season emergence. You can watch the video here: https://www.youtube.com/watch?v=T5_QXF-Px7s
Figure 1. On the left, soybean cotyledons are emerging from the soil after 10 days (planted April 9th), while the corn on the right is just below the surface, also 10 days after planting (April 16th).