The importance of flower and fruit management in jujube trees, which growers must not neglect

The jujube tree is a species that produces many flowers, with a very large amount of flower differentiation, but affected by the tree body and environmental conditions, flower drop and fruit drop are very serious, and the harvested fruit rate is generally only 1-2% of the number of flower buds. The causes of flower and fruit drop in jujube trees are many-sided. First, from the phenological phases of jujube, it can be seen that the bud stage of the jujube tree coincides with the rapid growth period of the fruiting branchlets and the vigorous growth period of the jujube heads; in this period the phenological phases overlap and nutrient competition is very intense. When it enters the initial flowering stage, the jujube heads are still in a vigorous growth stage, while at this time the growth of the fruiting branchlets gradually slows. In the same period, several organs of the jujube tree are all growing and active vigorously, and nutrient competition is very intense.

During the period from bud break and growth to fruit set, the jujube tree mainly consumes the nutrients stored in the tree body, that is, the nutrients manufactured in the previous year and stored in the branches, trunk and roots. Therefore we say that poor nutrition is one of the main reasons for poor flower bud differentiation and even abortion.

Poor external environmental conditions are also another main reason leading to the relatively serious flower and fruit drop of jujube trees. In the various jujube producing areas in the north, the flowering period is generally in early June. In ordinary years, this time is still in the dry season; during this period the rainfall is very small and the air humidity is very low, thus reducing the pollen germination rate of jujube flowers, causing poor fertilization and leading to a low fruit set rate. At the same time, this period is exactly the season when dry hot winds prevail in most areas of the north. This often causes a large amount of water loss from jujube flowers and the appearance of the "scorched flower" phenomenon, greatly reducing the fruit set rate. In addition, if the jujube flowering period encounters continuous rainy weather, because the rain soaks the flowers for too long, the pollen grains can absorb water and burst, greatly reducing the vitality of the pollen and affecting pollination. At the same time, continuous rain will make the temperature too low, which will also affect insect pollination. However, if light rain followed by clearing occurs during the flowering period, it is very beneficial to the flowering and fruit set of jujube flowers and can significantly increase the fruit set rate of jujube trees.

In addition, for some reason jujube trees often show fruit drop near the harvest period, which often brings certain economic losses to production. Furthermore, if there is a large amount of rainfall in the later stage, fruit cracking often occurs, and after jujube fruit cracks it is also prone to rotting, thus often causing relatively large economic losses.

In summary, to obtain higher fruit yield and higher fruit quality, in production it is necessary to strengthen the flower and fruit management of jujube trees, try to increase their fruit set rate, and adopt certain technical measures to minimize the occurrence of pre-harvest fruit drop and late-stage fruit cracking.