Why does Schisandra chinensis experience flower and fruit drop?

I. Flower drop caused by herbicide damage. (1) Symptoms: In spring, newly grown functional leaves curl; in severe cases, the leaves turn black, wither and fall off. When herbicide drift damage occurs during the flowering period, the petals wilt and drop early, pollen viability declines or the pollen dies, pollination becomes difficult, and flowers fail to set fruit; (2) Cause: damage from 2,4-D butyl ester herbicides; (3) Preventive measures: (1) It is recommended to use 2,4-D isooctyl ester instead of 2,4-D butyl ester. (2) If symptoms are found, spray with Kompo Kaipuke 500-fold fulvic acid foliar fertilizer.

II. Flower and fruit drop caused by low temperature and freezing damage. Late spring frosts in spring damage the growing tissues of Schisandra chinensis, resulting in flower and fruit drop due to destructive damage to physiological tissues.

III. Flower and fruit drop caused by unreasonable pruning. This is mainly caused by unreasonable pruning during the management of Schisandra chinensis, and by an unreasonable ratio and structure of vegetative branches and fruiting branches. Each fruit cluster of Schisandra chinensis requires about 50 healthy functional leaves to provide nutrients. Once the ratio of leaves to fruit clusters is unreasonable, flower and fruit drop due to insufficient nutrients is inevitable. The solution is to adjust the pruning method and try to ensure that the ratio of fruiting branches, flower-bud branches and functional branches is 1:1:1.

IV. Flower and fruit drop caused by insufficient trace elements. A lack or imbalance of trace elements will cause a large amount of physiological flower and fruit drop in Schisandra chinensis. In particular, a lack of boron will directly lead to flowers failing to set fruit or to flower and fruit drop. The solution is to apply fertilizer reasonably, carry out foliar fertilization regularly, and maintain a balance of various trace elements in the Schisandra chinensis plant.

V. Flower and fruit drop caused by drastic environmental changes. In seasons with long periods of low temperature and rain followed by a sudden rise in temperature, the physiological functions of Schisandra chinensis itself cannot adapt to the environmental changes, and in the short term this causes an imbalance in nutrient distribution within the plant, resulting in flower and fruit drop due to imbalanced nutrient distribution. This generally occurs in July-August and disappears naturally after the temperature stabilizes.

To prevent flower and fruit drop, the overall approach is to strengthen management in the early growth stage of Schisandra chinensis, achieve balanced fertilization, enhance tree vigor, and strengthen the plant's own resistance to adverse environments.