Chemical regulators of gibberellin status and their application in plant production

Gibberellins and inhibitors of their biosynthesis are widely used in modern agriculture, horticulture and viticulture. Their global market is in the range of US$ 500 million. The gibberellins GA3, GA4 and GA7 are primarily used to increase fruit yield and/or quality in fruit trees and table and wine grapes. Distinct steps of the gibberellin biosynthetic pathway can be inhibited by growth retardants: chlormequat and mepiquat chloride, ancymidol, flurprimidol, paclobutrazol, uniconazole, and the fungicides tebuconazole and metconazole and daminozide, trinexapac-ethyl and prohexadione-calcium are currently used in crop production. Growth retardants reduce shoot elongation, thereby lowering the risk of lodging in cereals, rice and oilseed rape, and making ornamentals more compact. A better canopy structure with improved formation of reproductive structures is induced in cotton and peanuts. In fruit and nut trees, less pruning is required and increases in crop yield and quality are obtained.