Size Matters: Accounting for Hemp Seed Size
NC State Extension has published a new factsheet discussing the variability in hemp seed size and how to ensure you are planting to meet your desired plant populations.
Whether you’re planting hemp for fiber, grain, or dual-purpose, having the appropriate plant populations is critical. A fiber-specific crop will require a very high seeding rate (over 1 million seed/ac) versus a grain-specific crop (400,000 – 500,000 seed/ac). Farmers often like to think in terms of seed weight per acre, for example, 50 lb/ac, and many seeding rate recommendations will be made in pounds per acre. However, there is significant variability in grain size among the diverse fiber and grain hemp varieties. Planting based on seed weight without accounting for grain size may result in over-or under-planting and not meeting the crop population target.
Ideally, the seed provider should supply 1,000 kernel weight or the number of seed per pound. If not, a sample of at least 200 seeds should be weighed to generate an individual seed weight. The seed provider should also provide a germination rate. These two numbers will allow you to accurately calculate the weight of seed needed to meet your desired population.
View the NC State Extension factsheet (https://content.ces.ncsu.edu/size-matters-accounting-for-hemp-seed-size-when-calibrating-your-grain-drill) to see a comparison of four fiber-specific hemp varieties: BaMa, Futura 83, MS 77, and YuMa 1.