2018 Summer Rain and Temperatures

Jarrod O. Miller, Extension Agronomist, jarrod@udel.edu

Corn shelling has been rolling where fields have been dry enough. Due to the highly variable rainfall and temperatures we have had since April, every field will probably be a little different. Many corn fields planted in late April should have started silking around July 9th, with other fields following. During the month of July, daytime temperatures fluctuated above 86°F several times, which may have reduced pollination. This may be more prevalent in fields that were planted in early May. Fields planted late May through mid-June may have been luckier; they should have been pollinating near the end of July, when daytime temperatures stayed out of the 90s.

When temperatures at night remain above 72°F, corn plants are stressed and consume some of the energy they had built up from the sun. There are several nights where this occurred over the summer, typically also associated with high daytime temperatures. This will reduce the amount of energy corn plants have to develop grains. This is not a doom and gloom statement, it is simply a way for Delaware farmers to asses any differences they may find across all of their planting dates.

Georgetown represents the southern end of the state, and typically had the highest night and daytime temperatures, but not by much. There are a few times (April 30, July 16) that Dover was a little warmer. There is a lot more variability in rainfall across the state than temperatures.

As most readers are aware, we are receiving high rainfall again, some which may have come from tropical storm Gordon over the weekend. Unlike temperature, there is high variability across the state. The earlier predictions from Hurricane Florence projected that our region may get 2-6 inches, but after this summer that seems normal. Current tracking as put us in a better position that our southern neighbors, but we are not done with hurricane season yet.