Is Sunflower Seed Size Important For Commercial Sunflower Production?

Growers often times request a certain size when ordering their Sunflower seed but researchers have consistently found little difference in performance of small to larger size seed.  Oil Sunflower seed is sized from the largest Size 2 to smallest as size 4.

In 2014 and 2015 Researchers in SD compared final plant populations produced by planting the 3 different seed sizes. They found no difference in final stand based on seed size.

In 2011 Researchers in Iran in compared germination percentages and early growth rates for 3 different seed sizes. They found that small and medium size seed germinated at significantly higher percentage than the large seed. The higher germination rate supported a trend for faster seedling growth measured by dry weight accumulation.

Growers can be confident when purchasing SF seed that all sizes can provide similar final production results. If any significant differences exist, smaller size 4 seed may have an advantage in the drier and saltier soils that Sunflower growers often encounter. Different seed sizes may require growers to adjust planters to get proper singulation. Following the manufacture’s specifications for sunflower seed size can result in uniform spacing and seed depth. Go to sunflower-partners.com for recommended planter settings.