There is only one type of plant growth regulator typically used in artichoke production: ProGibb® gibberellic acid, or GA3 (or other VBC brands such as Berelex®). ProGibb is used to increase the growth of the plant itself, as well as growth of the plant’s tender, edible flower bud, which is the harvested artichoke.
Growers produce two types of artichokes, the perennial and the annual forms, and ProGibb enhances both production systems. Growers use ProGibb in the artichoke regions of the European Union as well as in California, where nearly all of the artichokes grown in the U.S. are raised.
Perennial artichokes are a cool climate crop. The plants are grown for several years. After harvest, they are mowed to the ground and the plant re-grows for the following season. ProGibb is used after the plants have grown up and are beginning to initiate flowering stalks. Applications at this time elongate the flower stalk and advance the formation of the flower bud (the harvested choke). This allows an earlier harvest of plants that were treated. The untreated blocks are then harvested later, permitting the grower to spread out the harvest schedule.
The annual artichoke is planted from seed each fall and harvested the following spring. At that time the field is plowed under once again and a new crop is planted the next fall. ProGibb is used when the crop is still very small to help increase plant growth, causing earlier flowering and crop maturity. With ProGibb, growers can take advantage of earlier, more lucrative, harvest windows.