Jarrod O. Miller, Extension Agronomist, jarrod@udel.edu; Cory Whaley, Sussex Co. Extension Ag Agent, whaley@udel.edu; Jake Jones, Extension Agriculture Agent, Kent County, jgjones@udel.edu; Dan Severson, Agriculture Agent, New Castle County, severson@udel.edu
After a rapid increase in growing degree days and steady temperatures in late April, there has been a significant cooling effect over the last week. Fields planted in late April should still have emergence (Table 1/Figure 1), but we may find fields planted early May taking up to 10 days to emerge. Soil temperatures are following a very similar pattern to last year (Figure 2), with temperatures dropping off in early May, although 2021 remains a little warmer.
| Table 1: Accumulated Growing Degree Days Based on Planting Date (Emergence = 120) | |||
| Planting Date | New Castle | Kent | Sussex |
| Apr 15 | 192 | 225 | 231 |
| Apr 22 | 173 | 198 | 207 |
| Apr 29 | 131 | 149 | 160 |
| May 6 | 20 | 26 | 32 |
While temperatures have cooled off, soil moisture has been steadily dropping since late April, at least at our Georgetown research plots. This should mean plenty of planting time in drier field conditions, and with warmer temperatures to come, corn and soybean planting may remain ahead of schedule this year.
Figure 1. Accumulated Growing Degree Days in each County Since April 15th.
Figure 2. Soil temperatures in Georgetown over the last month.
Figure 3. Soil Moisture in Georgetown over the last month.