Wheat seeding rate recommendations in Kansas are in pounds of seed per acre and vary according to precipitation zone. However, seed size can have an impact in the final number of seeds actually planted per acre. A variety with larger kernels, when planted in pounds per acre, will result in less seeds planted per acre and possibly thinner stands. If the weather and soil fertility during the growing season are not favorable for fall tiller formation and survival, the thinner stand might reduce grain yields. Examples of varieties with large kernels include WB4458 and Ruby Lee.
On the other extreme, a variety with small kernels can result in above-optimal stand establishment, increasing plant-to-plant competition for available resources such as water, nutrients, and incident solar radiation. Additionally, planting in pounds of seeds per acre can reduce seed costs when wheat kernel size is relatively small. Seed size can be measured in terms of the number of seeds per pound. The “normal” range is about 14-16,000 seeds per pound, but it can range from less than 10,000 seeds per pound to over 18,000 seeds per pound. Although seed size is specific to each individual wheat variety, it can vary within variety depending on seed lot and seed cleaning process.
By Ryan Flaming, County Extension Agent, Agriculture & Natural Resources