6-Benzylaminopurine (6-BA) is a cytokinin-type plant growth regulator that plays a positive role in fruit setting in fruit trees. The core mechanism of action of 6-BA is to increase fruit setting rate by promoting cell division and regulating the level of endogenous hormones in plants.
Specifically, application of 6-BA during the flowering and young fruit stages of fruit trees can significantly promote pollen tube elongation and pollen germination, ensuring smooth fertilization and reducing flower drop.
Simultaneously, 6-BA can inhibit chlorophyll decomposition, delay leaf senescence, and transport nutrients such as amino acids and inorganic salts to the fruit, providing sufficient nutrients for young fruit development and reducing physiological fruit drop.
For example, in citrus and apple trees, spraying 6-BA after flowering can effectively increase fruit setting rate, with an average increase in the rate of high-quality fruit of 27%.
It is important to note that the timing and concentration of 6-BA application are crucial.
Generally, the first spraying should begin 7-10 days after flowering (when the fruit is about the size of a soybean), followed by a second spraying after 10-15 days. Focus the spray on the fruit stalk and young fruit to prevent uneven fruit shape or deformed fruit.
In addition, 6-BA is often used in combination with gibberellic acid and other ingredients to enhance fruit expansion. However, it should not be used alone after the second physiological fruit drop period to avoid affecting fruit color change or stimulating excessive summer shoot growth.
