We have observed a few ears of corn at black layer, while fields planted in late April have kernels with moisture contents around 30%. As of this week we have even observed a few fields across the state being harvested. Blacklayer needs around 2700 growing degree days, which most corn planted mid to late April has passed in Sussex County, and about to reach in New Castle County (Table 1). Most fields after that are probably a week or less behind with the heat we have seen.
While it has been cooler than July, day time temperatures have cycled between the upper 80s and low 90s, which may have caused a few grain fill issues in dryland fields. The steady rainfall observed north of Dover in July has tapered off, leading to some droughty dryland corn and soybean fields. Still, the region north of Harrington is still leading the state in total rainfall, as many storms continue to pass through the center or just south of Delaware this month.
Table 1: Accumulated growing degree-days based on planting dates through July 31st
| If you planted-> | April 14 | April 21 | Apr 28 | May 5 | May 12 | May 19 | May 26 |
| Sussex | 2930 | 2839 | 2758 | 2657 | 2557 | 2486 | 2347 |
| Kent | 2866 | 2773 | 2698 | 2617 | 2519 | 2454 | 2318 |
| New Castle | 2769 | 2683 | 2602 | 2531 | 2440 | 2380 | 2246 |
R1 = 1400 GDD, R5 (Dent) = 2190-2450, R6 (Blacklayer) = 2700
