Management for Increasing Corn Seeding Rates

January 31, 2024

Every season, a decision must be made regarding the planting rate for corn. The proper rate is based on many things including but not limited to soil type, actual and planned fertility, drainage, planting date, seed product, and anticipated rainfall or planned irrigation. At the end of the day, obtaining the highest return on investment (ROI) potential on every acre is the goal and to help optimize that, the best seeding rate and management is needed to help maintain plant health and harvestability.

First, seeding range should be matched with the potential ear/grain flex of the specific corn product as each corn product has its own unique characteristics. Additionally, the growing conditions within the area and each field help determine the seeding rate. Generally, corn products with greater flex may be planted at lower seeding rates because of the potential for more kernels per ear if growing conditions are favorable. The potential for fixed ear type products generally does not change dramatically under favorable growing conditions; therefore, more seeds per acre should be planted.

Channel® brand corn products are rated for being a flex or determinate style ear. A flex style ear product can carry more yield potential per ear than a determinate ear product. Channel® brand uses Bayer, Gen 5 testing to help determine the optimal seeding rate or amount of ear flex in every portfolio product. With Gen 5, products are planted across the country at multiple locations at a range of seeding rates to help determine the optimal planting rate and ear flex for each product.

Though it might seem best to plant all flex style plants to help save on seed, that is usually not the best idea. Flex style ears may not be the best choice in high yield environments when there is just not enough “ear flex” to hit the desired high yield potential. This is when a more determinate product, which can allow for higher seeding rates, may be best choice because they can carry more yield potential per acre than a flex style product. Often, if a flex style product is planted under a higher seeding rate, the ears shrink down and the grain tips back on the ear, reducing overall yield potential. A determinate style ear usually maintains the same ear size regardless of seeding rate and at higher seeding rates results in more ears per acre and a potentially higher yield return per acre. However, under situations where moisture stress occurs, a flex product may provide an advantage in that the product can “adapt” to the drier conditions, where a determinate ear product cannot “adjust”.

When seeding rates are raised, consideration should be given to keeping the plants healthy and fed properly. Since there are more plants, more water and fertility are needed. This may seem detrimental to overall ROI; however, to hit the highest yield potential, the more determinate ear style product is likely needed at a higher seeding rate.

The increase in seed cost needs to be considered when determining the desired seeding rate to help maximize the ROI for each product. Every year input prices vary along with market grain prices; therefore, calculations should be completed annually for each field. It is not a one size fits all approach.

In an irrigated scenario, an increase in the amount of water for those extra plants is likely to occur. Higher amounts of nitrogen, phosphorus, potassium, and micronutrients will be utilized to support the higher planting densities. Building a strong stalk and healthy plant is very important in high populations because as density is increased, the competition for sunlight is increased. As a result, overall plant height is increased as they reach for sunlight and likely have a decrease in stalk diameter. Therefore, it is key to keep plants healthy through proper fertilization. Potassium is a nutrient that is sometimes undervalued but is a key for helping to build a strong stalk and healthy plant.

Another factor that needs consideration is the potential for increased disease pressure with increased seeding rates. With more plants, an increased canopy is likely to help in soil moisture retention and could potentially increase the risk for more fungal disease. A fungicide application may be beneficial to help keep plants and stalks as healthy as possible throughout the year and into harvest.

In conclusion, it is important to evaluate planting rates every year and for every field, because there is more to be considered when increasing seeding rates to help maintain strong healthy plants as seeding rates are increased.

Austin Merz
Channel Agronomist