Warm, wet April led to wide variation in planting
Weather factors impacting corn yield and quality include the amount of precipitation and the temperature just prior to and during the corn-growing season. These weather factors interact with the corn variety planted and the soil fertility. Grain yield is a function of the number of plants per acre, the number of kernels per plant, and the weight of each kernel. Cold or wet weather at planting could reduce plant numbers or hinder plant growth, which may result in lower yields per area. Some dryness at planting and early growth time is beneficial, as it promotes a deeper root system to access water better later in the season.
Overall in 2016, the spring was warmer than average for almost the entire United States. However, April was much wetter than normal, especially in the Pacific Northwest and Southern Rail ECAs, leading to an extended period of planting and emergence.
In the Pacific Northwest ECA, relatively warm temperatures in March led to average temperatures in April, and below-average temperatures in May. April was much wetter than normal, leading to many areas with delayed planting, or with early- and late-planted fields.
The majority of the Gulf ECA experienced average precipitation, but warmer-than-average temperatures during the spring months. Many areas west of the Mississippi River were much warmer and drier than average, which led to early planting, especially in Missouri.
The Southern Rail ECA was warm, but it experienced its fifth wettest spring (in over 122 years), which delayed corn planting, primarily in the north central to northeast part of the area.