Alfalfa seed coating can help increase seedling survival rates, resulting in an equal or higher number of seedlings per acre with the same pounds per acre of product. Optimal alfalfa stand establishment is not determined by how many seeds are planted per acre but by the number of successfully established seeds that become harvestable plants.
What to Consider
Establishing a stand. An alfalfa crop with high yield potential begins with 20 to 30 healthy seedlings per square foot. Obtaining a successful stand can be influenced by several items including site selection, land preparation, a firm seedbed, proper planting depth, variety selection, planting date, seeding rate, planter calibration, pest control, seed inoculation, environment, and other factors.1 Selecting alfalfa seed coated with the right combination of fungicide, growth promotor, Sinorhizobium meliloti bacteria, and a protective seed coating can help improve early-season vigor, stand establishment, and root system development, which can potentially result in a longer stand life.
What is in a seed coating? Bayer’s alfalfa seed coating consists of 1) a seed treatment to help promote early-season vigor, 2) Sinorhizobium meliloti bacteria to promote nitrogen-fixing nodule development, 3) fungicide to help fight early-season diseases such as Phytophthora, Pythium, and downy mildew and 4) a lime-based coating with sulfur and molybdenum. The coating can help improve moisture absorption, germination, and nodulation. Bayer’s alfalfa seed coating increases the weight of the seed by 34%.The 34% seed coating helps decrease seed mortality, which can result in a higher number of seedlings established with the same pounds per acre of product. The result is more seedlings per acre and higher yield potential from the thicker, healthier stands. The target for alfalfa stand establishment is not the number of seeds planted per acre but by the number of successfully established seedlings that become harvestable plants.
Seeding rate and planter calibration. University and commercial research have shown that coated seed should be planted at the same pounds per acre rate as non-coated seed. Planting 34% coated seed can result in approximately 30% fewer seeds planted per acre. However, because of the benefits provided by the seed coating, final seedling stands should be equal to or higher than with non-coated seed.
The 34% coated seed weighs more than noncoated seed, which results in the seed flowing through planting equipment at a different rate than non-coated seed. Some research trials have shown that coated seed flows approximately 30% faster than non-coated seed, while others had no change in the rate of seeding.2 Alfalfa growers should carefully calibrate planters for the specific seed they are planting to help ensure they are planting the desired number of pounds per acre. Always refer to the manufacturer’s operating manual before performing any maintenance. Alfalfa seed coating can help 1) promote early-season vigor, 2) increase seedling survival rates and stands, 3) manage early-season diseases, and 4) lower the number of seeds plants while providing benefits that non-coated seed may not.
1 Rocateli, A., Arnall, B. and Manuchehri, M. 2017. Alfalfa stand establishment. Oklahoma State University Extension. PSS-2089. https://extension.okstate.edu/fact-sheets/alfalfa-stand-establishment_2017-1.html.
2 Leep, R., DeYoung, J. and Min, D. Coated alfalfa seed, is it worth it? Michigan State University. Department of Crop and Soil Sciences. https://forage.msu.edu/extension/coated-alfalfa-seed-is-it-worth-it/. Web sources verified 04/01/21. 3018_S2