Farmers make hundreds—if not thousands—of important decisions each growing season. The timing of corn harvest is a critical crop management decision growers make each fall, as proper timing has implications for harvestable yield, grain drying costs, and profits.
On the one hand, early harvest can reduce field losses, but doing so increases drying costs and may reduce grain quality and storability. On the other hand, harvesting later reduces drying costs but may result in excess deterioration of the crop, which may decrease harvestable yield and quality.
There is a right time to harvest each field, but competing demands and weather play an important role in achieving the goal of harvesting on a specific date. Nevertheless, growers who take a systematic approach to monitoring their fields during dry-down and evaluating loss potential can make the best possible decision in prioritizing fields for harvest.
“Tracking maturity stages and grain moisture are important things to do right now,” said Louis Sutton, Regional Product Manager. “Then noting crop conditions during drydown helps growers make the best possible harvest timing decisions.”
Many different stresses to the corn plant can lower stalk quality. Drought stress, reduced sunlight, insect and disease pressure, lack of nutrients, and hail damage are stresses that can result in poor stalk quality. Even high yields put stress on a plant and may lead to stalk problems.
Growers are encouraged to monitor their fields as harvest approaches to identify stalk quality problems and prepare to harvest before field losses occur. Identify fields right now that are at the most risk before the expected harvest date for stalk problems.
Maintaining grain quality through harvest and storage is critical to optimizing profitability. Harvest timing is the primary factor the grower controls to maximize grain quality. Harvesting grain at too high a moisture content can result in severe kernel damage during threshing and drying. Conversely, allowing corn to sit too long in the field can lead to reduced yield and quality if stalk, ear rot diseases, or insect feeding damage are increasing.
Ear rots are a particular concern if weather conditions turn wet in the fall. If ears are in contact with the ground under these conditions, ear rots may develop quickly. Growers should scout fields regularly during the drydown period to inspect ears and for possible disease development. If these problems are severe, growers should consider harvesting early and drying grain to below 18% moisture to stop the progression of insects and diseases and maintain the best possible grain quality.
Most growers have experienced the need to harvest corn at high moistures when late planting or cool temperatures have delayed crop development—and are well aware of the devastating effects on grain quality. For this reason, grain quality experts would like to see corn fields dry below 20% moisture before harvesting. However, if grain quality is deteriorating, beginning harvest at about 25% moisture may be necessary, especially if there are many at-risk fields to follow.
“Timing corn harvest to maximize profitability usually means finding a good balance between maximizing bushels harvested and drying costs,” said Sutton.
Proper combine settings are also critical to reduce harvesting losses and increase harvested grain and profits. Combine settings must match crop conditions, which change from field to field and even day-to-day. Continual monitoring of ears and kernels lost while harvesting is required to make necessary adjustments to the combine.