AUBURN UNIVERSITY, Ala.—Planting season is in full swing across the state as farmers battle cool temperatures and bouts of rain to get corn in the ground and a stand established.
Eros Francisco, an Alabama Cooperative Extension System grain crops specialist, said the wet and cool conditions Alabama farmers have seen thus far in 2023 are causing corn plants to struggle through the early stages of growth.
“Under such conditions, corn plants can look stunted and yellow due to low nitrogen uptake and/or limited chlorophyll synthesis, which tends to correct as soon as the weather is more favorable—or warmer and drier,” Francisco said.
Deciding to Replant
Francisco, who is also an assistant professor in the Auburn University College of Agriculture’s Department of Crop, Soil and Environmental Sciences, said eventually farmers face the tough decision of whether to replant a field—or part of it—where the corn stand was jeopardized. Factors may include poor seed quality, incorrect seeding depth, soil that is too wet or too dry as well as deer or hog damage.
“We developed a yield impact estimate on corn yield based on a field trial conducted last year where we compared different seeding rates and planting dates in Fairhope, Alabama,” he said. “There are specific examples that producers can take and apply on their own farms, but there is a very important takeaway.”
Francisco said the longer the grower takes to decide, the higher the yield impact will be.
“Replanting decisions must be made quickly, but producers should also consider the costs related to replanting—such as new seeds, operational hours, extra burndown and other additions,” he said.
Nutrient Management Considerations
A producer’s ability to manage nitrogen in the soil directly affects final yield.
“Consider the four Rs of plant nutrition,” he said. “Right source, right rate, right time and right place. The right rate is about yield expectations related to field conditions and may vary between 1.1 and 1.25 pounds of nitrogen per bushel of corn yield.”
Francisco said the right source refers to the different types of fertilizer. For example, when working with urea, remember that nitrogen begins to volatilize without soil incorporation through rainfall or irrigation within 48 hours of application. Right time means making nitrogen available when plans need it most.
“Farmers shouldn’t delay side-dressing nitrogen in corn,” he said. “Our results show that nitrogen must be available up to V6 to show maximum effectiveness.”
Francisco said recent USDA crop report numbers reflect the impact of 2022 weather conditions on corn growth and development. This is especially true in the northern and central parts of the state.
“According to the weather predictions center, La Nina may fade away and leave space for normal conditions that indicate better rainfall and temperatures through the summer, when compared to 2022,” he said.
Learn more about corn plant development and cultivation by visiting www.aces.edu. Read more about corn development in the Extension publication, How a Corn Plant Develops.