Parental ratio in production of Certified Seed of hybrids of sunflower
12. Where a female male-sterile component and a male component which does not restore male fertility have been used for the production of Certified Seed of hybrids of sunflower, the seed produced by the male-sterile parent shall be blended with seed produced by the fully fertile parent. The ratio of male-sterile parent seed to male-fertile parent seed shall not exceed two to one.