Gibberellic Acid, GA3, is a plant growth hormone. It is added to select sunflower heads and sterilizes those specific plants, making them female. The Hulke Lab has been working on GA over the past 2 weeks.
As seen in the photos above, the GA3 is placed in the center of the sunflower head very carefully. The first dose is done when the heads are about quarter size. The second dose is about 2 days later, when the head is around the size of a quarter. Each dose is 2-3 drops.