Why does an apple tree keep dropping its apples? Causes and solutions

The apple is one of the fruits we commonly eat in daily life. It has a great many varieties and is rich in vitamin C and dietary fiber, making it very popular with consumers. During apple cultivation, some growers have reported that apple trees keep dropping apples. What are the causes? How can it be solved?

1. What are the causes of apple trees constantly dropping apples?

1. Natural fruit drop

Apple trees naturally drop fruit during the fruiting period; this is one of their growth habits. Generally, apple trees have 2 peak periods of fruit drop: the 1st is about 10 days after flowering, and the 2nd is from July to August.

2. Excessive tree vigor

This may be caused by improper fertilizer use. Apple trees may drop fruit because of too much nitrogen fertilizer, or insufficient phosphorus and potassium, causing an imbalance in the carbon-to-nitrogen ratio within the tree, which leads to excessive vegetative growth and an imbalance between vegetative growth and reproductive growth, resulting in heavy fruit drop. It may also be that the apple tree bears few fruits, so a large amount of nutrients has nowhere to go and is instead supplied to the growth of vegetative branches, which can also cause excessive tree vigor.

3. Fruit drop caused by pests and diseases

For example, rot of the trunk or fruit of the apple tree, such as canker, ring rot, and anthracnose, can all cause apple trees to drop apples.

4. Insufficient water

When soil moisture is insufficient, the water entering the fruit decreases accordingly. In severe drought weather, the branches and leaves will even take the water originally in the young fruit, causing the young fruit to drop from lack of water.

5. Impact of natural disasters during the flowering period

Low temperatures and frost during the flowering period cause flower buds to freeze; strong winds and rainy, overcast weather restrict the activity of pollinating insects; and sandstorms stick to and cover the stigma, preventing pollen from germinating.

6. Few pollinating insects

During the flowering period, there are few pollinating insects such as mason bees and honeybees, which affects pollination and fertilization. In addition, artificial pollination cannot be carried out in time, leading to flower drop.

7. Insufficient pollen amount

The arrangement of pollinator trees is unreasonable; the orchard lacks pollinator trees, or the flowering periods of the varieties are not consistent, or the pollen is incompatible, so pollination and fertilization are poor and flowers drop.

2. How can apple tree fruit drop be solved?

1. Topdressing under the tree

According to the orchard's fertility foundation and the tree's nutritional status, 20-30 days before fruit drop occurs, apply chemical fertilizers such as nitrogen, phosphorus, and potassium to the fruit trees, and apply an appropriate amount of high-quality organic fertilizer. This can prevent apple tree fruit drop.

2. Foliar spraying of fertilizer

To quickly supplement the tree's nutrition and reduce the fruit drop rate, when the apple tree is near physiological fruit drop, carry out 2-3 consecutive foliar fertilizer sprays. You can spray 0.5% urea water and 0.4% potassium dihydrogen phosphate solution.

3. Spray plant growth regulators.

Before the arrival of physiological fruit drop in apple trees, spray a 20-40 mg/L naphthalene acetic acid solution once every 10-15 days, for 2-3 consecutive sprays, which can effectively control physiological fruit drop.

It is worth noting that this measure must be based on improving the tree's nutrition to be effective; its effect on physiological fruit drop caused by other reasons is not obvious.