The flower bud differentiation has 2 segments, first morphological differentiation, the medium and short branches stop growing after a tender tip, and with the extension of the stop, the tender tip becomes a small dot. In Yuncheng fruit area, the dots of the short shoots before late June are getting bigger and bigger, and the morphology looks like a flower bud, but the Shanxi Fruit Research Institute cut the top bud microscopic inspection and found that the top bud is still a vegetative growth point. Short shoots and large top buds, which are the result of more nutrient accumulation. From the time the short branch stops growing to the time when no flower bud is found in the original basal pre-base (flower fetus) in the bud, it is called morphological differentiation, that is, the top bud is full in appearance and looks like a flower bud. However, flower bud differentiation requires a certain amount of stopping for a long time, and a certain amount of organic nutrients needs to be stored in the bud to form the original base of the flower. This is also for flowers, requiring early growth, early stopping, and early accumulation.
Flower buds are physiologically differentiated after the original base of the flower (flower fetus) in the bud until before flowering. According to a report by the Shanxi Fruit Research Institute many years ago, in an orchard in Linyu County, Yuncheng City, the short branch found the original base of the flower in the bud on June 23. However, there is no primitive base of flowers in the top buds of medium and long twigs, because the reason why medium and long twigs stop growing later than short shoots, and the nutrient accumulation has not yet reached the conditions for bud change and formation of the original base of flower buds, so the morphological differentiation time of medium and long twigs will be delayed. This is also known to everyone that in order to bloom in June and July, it is necessary to properly control water, because watering will make the branches that stop growing rush out and grow, consume nutrients, and are not conducive to flowers, especially trees with no fruit and few fruits on the tree should pay more attention to this. The tree is more vigorous, after the spring tip stops growing, the number of long strips more than 33 cm on the tree is large, no matter how much fruit is on the tree, do not water and flush high phosphorus, should use a fertilizer gun to apply high phosphorus, because watering and flushing high phosphorus, will make these stopped long strips quickly rush out and consume nutrients, but not conducive to flowering.
The morphological differentiation time of flower buds is related to sooner or later, the length is related to the long, medium and short branches stopping the length sooner or later, it is also related to the number of flowers and fruits on the tree, the strength of the tree, and whether there is top dressing before flowering. Some scientific research departments have reported that orchards with top dressing before flowers have leaves "working early" and morphological differentiation early, and orchards without topdressing before flowers are relatively late in morphological differentiation.
The physiological differentiation time of flower buds is not consistent on a tree, generally the physiological differentiation time of short fruit branches is early, followed by medium fruit branches, and long fruit branches enter the physiological differentiation time at the latest. Because only after completing the morphological differentiation, the bud has the original base of the flower bud (flower fetus) in the bud, can it enter the physiological differentiation.
The physiological differentiation of flower buds is also fast and slow, for example, there are many fruits on the tree, a large amount of tree nutrition is used for fruit growth, physiological differentiation is slow, and physiological differentiation of small trees is fast. The physiological differentiation of orchards topdressed in late May and early June is fast, which is the same as seen in production practice, all orchards that top dressed in late May and early June, in early to mid-August you will obviously see full flower buds and large flower buds. However, in late May and early June, there is no top dressing orchard, and it is not clear whether it is a flower bud or not, because the top bud is very strawy.
Physiological differentiation of flower buds is a gradual process, lasting up to nine months, and by the time of flowering, the flower pieces cannot bloom without completing differentiation, and it is a large leaf bud. This kind of large-leaf bud mostly occurs on young trees and small trees, or lack of fertilizer during the physiological differentiation of flower buds, flower buds, the common people call it poor in the fetus, the fruit does not grow large, the flower bud full fruit can grow up, because it is rich in the womb. There are data reports: a vegetative growth point bud becomes a flower bud primitive base, from this moment, the bud primitive base cells are constantly dividing and multiplying, to the second year before flowering, a full flower bud has 2.5 million cells in it, the cells temporarily stop dividing during flowering, after pollination and fertilization, the cells in the young fruit begin to divide rapidly, especially the fastest cell division within 15 days after flowering, until the cells stop dividing 40 days after flowering. Therefore, there can be no lack of fertilizer during the physiological differentiation of flower buds.
Author: He Jucai, lecturer of China Agricultural Fruit Science Research Institute
Source: Zhongnong Le