Detailed Explanation of Key Technical Points for Growing Colored Bell Peppers in Greenhouses

Colored bell peppers rank first among vegetables in vitamin content. They are rich in vitamin A, vitamin B, vitamin C, carbohydrates, fiber, calcium, phosphorus, iron and other nutrients. Colored peppers can be stir-fried just like other ordinary peppers, and their colors remain bright and appetizing; using them in cold dressed dishes shows their advantages even more. With the development of greenhouse cultivation techniques, delicious colored bell peppers can be enjoyed all year round. Let's take a look below at this introduction to greenhouse cultivation techniques for colored bell peppers.

I. Greenhouse Cultivation Techniques for Colored Bell Peppers

1. Reasonable watering: After the colored bell peppers are planted and have survived, water them moderately. When the first fruit first appears, begin watering and topdressing. During the flowering and fruiting period, the soil should be kept moist; water once every 5 to 10 days according to how dry or wet the soil is. When the temperature is low, water on a sunny morning; when the temperature is high, water in the evening instead. Dry conditions and high temperatures inside the greenhouse will affect flowering and fertilization of colored bell peppers and cause flower drop. At this time, pay attention to watering to lower the temperature and increase humidity, and keep the relative soil moisture content at 60 to 70%.

2. Timely fertilization: For colored bell peppers, apply a strong-seedling fertilizer at the seedling stage, using 5 to 10 kg of compound fertilizer or urea per mu; apply a fruit-setting fertilizer at the early fruiting stage, using 20 kg of compound fertilizer or urea per mu; afterward, topdress once about every 20 days, each time applying 15 to 20 kg of compound fertilizer per mu diluted in water. In the middle and late fruit-harvesting stages, spray foliar fertilizer once every 7 to 10 days with 0.2% monopotassium phosphate plus 0.1 to 0.2% zinc sulfate.

2. Temperature management: The suitable temperature for the growth of colored bell peppers is 20 to 25°C during the day and 15 to 20°C at night. When the temperature inside the greenhouse is below 10°C or above 35°C, pollination is difficult and flower and fruit drop are likely to occur. The air humidity requirement is 70%. When there is plenty of sunlight at noon during the day and the weather is hot, shade netting should be used to lower the temperature. When the outside temperature rises, gradually increase ventilation to help the plants pass the summer safely.

3. Pruning and vine hanging: Select and retain 2 vigorous main branches per plant. Remove the flower buds of the first pepper and the side shoots at the base in time. Start retaining peppers from the 4th to 5th nodes, mainly letting the main branches bear fruit, and remove side branches promptly afterward. Side branches in the middle can be pinched off after retaining 1 fruit. Keep 2 branches per plant growing upward at all times. Generally no hilling is done; fix each main branch by hanging it with 1 anti-aging plastic string.

4. Flower and fruit thinning: Colored bell peppers have strong branching ability, so branches should be pruned before flowering, and side branches that grow out should be removed in time. During the growing period, thin flowers and fruits in time. Do not keep the first pepper; retain fruits in a crossing pattern, keeping one fruit per fork, and remove all other flowers and fruits, ensuring that each plant bears no more than 6 fruits at the same time to help the fruits enlarge. Remove withered, old, yellow and diseased leaves on the lower part in time to concentrate nutrients and improve light conditions.

1. Timely harvesting: After the colored bell pepper fruits stop enlarging and change color, harvest them in time, preferably in the morning. When harvesting, pick the fruit together with the entire fruit stalk and do not leave a stalk in the leaf axil.

II. How to Enhance the Color of Colored Bell Peppers?

1. Sufficient light

Light is one of the key factors directly affecting the coloring of colored bell peppers. Therefore, the light conditions of the solar greenhouse should be improved to prevent insufficient light. During the coloring period of colored bell peppers, attention must be paid to cleaning the greenhouse film in time to improve its light transmittance. In addition, old leaves and yellow leaves on the lower part of the plants should be removed in time to ensure good light and ventilation between plants and promote uniform coloring of the colored bell peppers.

2. Temperature control

The most suitable temperature during the coloring period of colored bell peppers is around 25°C. This temperature directly affects the coloring of colored bell peppers, as lycopene is more easily formed. If the temperature in the solar greenhouse is too high, even above 35°C, it will be unfavorable for the color change of colored bell peppers.