Statewide
Seed size in grain sorghum ranges from about 12,000 to 16,000 seeds per pound. Grain sorghum in general will sometimes have slightly smaller seed size (18,000 seeds per pound). Usually seed companies will select what they believe is their best seed to bag for your planting and so this tends to be the larger seed. Planting seed size for hybrid seed most commonly runs about 13,500 to 15,000 seeds per pound. For planting seed I am most likely to assume 14,000 seeds per pound if I don’t know the specific number.
Seed size should not really affect a farmer’s decision on which seed to select. Good germination is much more important. Seed and subsequent seedling vigor is not necessarily higher with larger seed size though as a grower we would likely feel more confident in a larger seed. No correlation has been demonstrated between seed size and eventual yield. In dry conditions, larger seed needs to imbibe more moisture to germinate, but this is not normally an issue for grain sorghum. It can be with larger seeded crops like soybean or sunflower.
The one caveat about large grain sorghum seed is that at 13,000 seeds per lb. versus smaller seed at 15,000 seeds per lb., is the larger seed has 13% less seed in a bag so it will not plant as far (essentially costs about 13% more to plant) when using an air-vacuum planter. If you have an older planter that uses plates, your pounds-per-acre seeding rate will stay the same but the seed drop will decrease. Because many Texas producers plant more than enough seed, I would not worry about the slight reduction in seeding rate. Plate planters should be calibrated to ensure they are delivering the desired amount of seed regardless of seed size.
