What to Do About Pepper Flower and Fruit Drop? Causes and Control Methods Explained

Pepper is an important vegetable and seasoning, widely grown in China. During pepper cultivation, improper management can lead to flower and fruit drop, thus affecting yield. So, what are the causes of pepper flower and fruit drop? How to prevent and control it?

I. What are the causes of pepper flower and fruit drop?

1. The variety selected is not suited to the local environment.

2. Sowing too early or off-season cultivation

During the pepper growing period, the temperature cannot meet its needs. In particular, when the soil temperature is below 18°C, the physiological function of the root system declines; at 8°C the root system stops growing, leaving the plant in a state of neither living nor dying. When the air temperature is below 15°C, although the plant can flower, the anthers cannot release pollen. If the temperature remains low for a long time, the three-drop disease (flower drop, bud drop and fruit drop) is likely to occur.

3. Air temperature too high during the pepper growing season

When the air temperature is higher than 35°C, fertilization cannot occur; or when the soil temperature is higher than 30°C, the root system is damaged and flowers drop.

4. Too little or too much water

During the pepper growing period, if there is a long spell of continuous overcast and rainy weather, insufficient light, or relative humidity below 70%, or excessive nutrition or disordered reproductive growth, causing the plants to grow leggy, too much or too little water can all lead to flower drop, bud drop and fruit drop.

5. Insufficient soil fertility

Phosphorus deficiency or boron deficiency in the soil, or poor seedling quality and inadequate management, mean that after transplanting the plants cannot recover and grow quickly. When the hot season arrives, the branches and leaves have not grown out and cannot close the ridges. In addition, sweet peppers and hot peppers have shallow root systems, mainly distributed in the 5-15 cm topsoil layer, and are easily damaged when the soil temperature rises, causing flowers to fail to set fruit, or causing flower drop and bud drop.

6. Pests and diseases

Such as bacterial spot, bacterial leaf spot, anthracnose, viral disease, tobacco budworm and tea yellow mite. Severe damage can easily lead to defoliation.

7. Caused by fertilizer burn or pesticide burn.

II. How to prevent and control pepper flower and fruit drop?

1. Choose suitable varieties

Select varieties suited to local conditions that are tolerant of low temperature and weak light, or early-maturing varieties. Such as Tianza No. 1 and No. 2, Nongle, Jumbo Horn Pepper, Zhongjiao No. 2 and No. 3, Nongfa, Liaojiao No. 4, Zaofeng No. 1, Zaozha No. 2, Xiangyan No. 1 and No. 4, etc.

2. Sow at the right time

Scientifically determine the sowing date suitable for the locality, so as to meet the needs of sweet peppers and hot peppers, which have an optimum growth temperature of 20-30°C and an optimum soil temperature of 25°C. It is necessary to consider whether the greenhouse temperature meets the requirements, whether the soil temperature can reach above 18°C, and whether the growing season can avoid high-temperature damage and other such problems. To prevent damage caused by low temperature and injury from direct sunlight, management should be used to bring temperature and humidity to the levels required for the growth and development of sweet peppers and hot peppers, especially soil temperature, which is often more critical, and to prevent leggy growth or stunted growth.

3. Fertilize reasonably

It is recommended to apply compost fermented with enzyme bacteria, or fully decomposed organic fertilizer with added heating materials such as horse manure, or Lufeng biological fertilizer at 50-80 kg/666.7 sq m. Apply the vine-promoting fertilizer, fruit-setting fertilizer and vine-recovery fertilizer according to the seedling condition, adopt formula fertilization technology, and prevent fertilizer deficiency in the late growth stage.

4. Focus on pest and disease control

Pay attention to controlling bacterial spot, anthracnose, viral disease, tobacco budworm, tea yellow mite and other pests and diseases. If it is viral disease, spray 5% Huanzhong Junduqing 300-fold solution or 1.5% Zhibingling emulsifiable concentrate 800-fold solution, once every 7 days, for 3-4 consecutive sprays. If there is tea yellow mite, spray the undersides of leaves with 15% Daxingling emulsifiable concentrate 300-fold solution, 20% Dicofol emulsifiable concentrate 800-fold solution or 20% Mieshaoli 2000-fold solution for control.

5. Regulate soil temperature

For those using plastic film mulching, the film can be broken open when the hot season arrives to prevent the soil temperature from getting too high. The use of shade netting is recommended.

6. Harvest at the right time

Fruits should be picked when they turn from pale yellow to green. Thin out branches and pinch off growing tips. Before the Start of Autumn (Liqiu), thin out old branches, weak branches and pest- or disease-damaged branches once, and in combination with branch thinning apply a quick-acting fertilizer once to restore vitality, promote branching and flower bud formation before fruiting again, and prevent premature aging.

Overall, the main causes of pepper flower and fruit drop include unsuitable varieties, sowing too early or too late, improper temperature, water and soil management, and pest and disease damage. If growers pay attention to these aspects and take corresponding preventive measures, they can effectively control flower and fruit drop.