The low yield or even no grain of litchi is largely due to the influence of various factors in the process of flower bud differentiation, flowering and fruit development, which leads to the general failure of embryo and fruit growth and development, or even zero fruit. Flowers are fruitless, so how to strengthen the protection of flowers is very important in litchi management.

Reasons for Litchi Fruit Drop (Flowering Period):

1. Fruit drop is caused by poor pollination and fertilization 7 ~ 12 days after female flowers wither.

2. About 25 days after the female flower opens, the endosperm degenerates and declines, which affects the general development of the embryo, thus balancing the endogenous hormones in the fruit and forming the fruit.

3. From 50 to 55 days after opening, the pulp of female flowers begins to grow from the base of seeds, and about13 of the seeds are wrapped. This is the rapid growth and development stage of pulp, which requires a small amount of nutrients. In addition, the summer shoots began to germinate and the root system developed vigorously, which led to the balance of nutrition and reproductive development and fruit drop.

4. Pre-harvest fruit drop: usually in pre-harvest 10- 15 days, the fruit is fully developed, and its size and weight increase rapidly, requiring a small amount of nutrition. When there is a lack of nutrition supply or poor conditions, some varieties will lead to fruit drop. In addition, during this period, the progress of fructose, such as long-term continuous rain or sudden rain, will cause a small number of fruits to crack.

5. In the process of flowering, fruiting and development, pests and diseases are also one of the main causes of fruit falling and cracking, especially litchi fungal mildew, anthracnose, litchi moth, litchi stinkbug and other pests and diseases.

Measures to protect fruits

1. Cultivate strong spikes

Strengthening the planting management of litchi, cultivating timely and healthy autumn fruit mother branches, laying the foundation for flowering and fruiting, and cultivating short and strong panicles with sound development and high proportion of female flowers through a series of regulation and promotion techniques are the conditions for litchi fruiting.

2. Create conditions for universal pollination and fertilization.

Most kinds of female flowers must be pollinated and fertilized to make the ovary develop and bear fruit. Of course, the female and male flowers of litchi are bound to a unified flower spike, but most varieties of female and male flowers often do not open at the same time, but are commonly known as batch-opening female and male flowers. Of course, mixed orchards can be opened at the same time, and then bees, insects or wind continue to pollinate, but rainy days often affect pollination and fertilization, resulting in flowering and fruitlessness.

3. Use growth regulators to protect fruits

Using growth regulator to protect fruit, spraying it once after 15 days, spraying it twice a week or so, spraying it 2-3 times, can significantly increase fruit drop.