The Biological and Genetic Mechanisms of Yield Self-Regulation in Apple Tree (Malus × domestica Borkh.)

Apple-tree (Malus × domestica Borkh.) belongs to the genus Rosaceae. Due to its adaptability and tolerance to different soil and climatic conditions, it is cultivated worldwide for fresh consump-tion. Therefore, the priorities of apple growers are the high-quality of fruits and stable yield for high production. In total about 90 to 95 percent of fruits should fall or be eliminated from apple trees to avoid overcropping and poor-quality fruits. Several technologies such as handwork, me-chanically or chemical substances are used for fruit and bud elimination. The most profitable in commercial orchards is the use of chemicals for elimination, but due to the European Green Deal more environmentally sustainable solutions are required. Elimination of fruitlets is influenced by several factors. Additionally, the apple trees have the self-elimination mechanism. This is de-termined by apple genotype, physiological futures and genetics. This review focuses on the bio-logical factors and genetics mechanisms in apple yield self-regulation for better understanding the regulatory mechanism of fruitlets abscission for future breeding programs targeted on self-regulating yield apple varieties