Growing Degree Days for the Last Month

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

Growing degree day (GDD) accumulation has been pretty steady for the last month, with most corn emerging within a week of planting. In Sussex County, we have observed some fields between V4-V6(4-6 visible leaf collars) that were planted between April 22^nd and 29^th.

Sussex and Kent counties have been accumulating about 14 growing degrees every day, with New Castle at 12. Expect to hit V6 around 475 GDD, so anything planted between April 22-29^th could reach V6 this week in the lower portions of Delaware. For those fields that received manure or with legume nitrogen credits, you should be thinking about running a PSNT. Any nitrate released with warmer weather could have been lost to leaching or denitrification with the past week’s rainfall.

Table 1: Growing degree days accumulated over the last few weeks