Selection of Greenhouses for Colorful Bell Peppers and Key Cultivation Techniques

The colors of colorful sweet peppers include red, golden yellow, purple, light purple, cream yellow, and others. The fruit shape is square and large, the skin is smooth, and the flesh is thick, with flesh thickness reaching 5 to 7 mm, single fruit weight 200 to 400 grams, and a maximum of up to 500 grams; the taste is sweet and crisp, the nutritional value is high, and it is suitable for eating raw. Colorful sweet peppers are tolerant of low temperatures and weak light, and have a long growth period. In recent years, China has introduced colorful sweet peppers from countries such as the United States, the Netherlands, and Israel, planting them in the suburbs of Beijing, Shanghai, and other cities, with good results, and they have developed rapidly nationwide. The greenhouse cultivation techniques are introduced as follows:

I. Variety selection

Choose first-generation hybrids with large fruit, bright color, smooth skin, sweet and crisp taste, and strong disease resistance. For example: Huang Manao (bred by the Beijing Agricultural Extension Station), whose young fruit is green and mature fruit is golden yellow, square lantern-shaped, with fruit length and diameter both about 10 cm, single fruit weight about 200 grams, good taste, strong disease resistance, and high yield; Zijing, whose young fruit is light purple and mature fruit is red, lantern-shaped, with fruit length and diameter both about 10 cm, relatively thick flesh, good taste, strong disease resistance, and high yield; Mazurka (introduced from the Netherlands), whose young fruit is green and mature fruit is bright red, square lantern-shaped, with fruit length and diameter both 10 to 12 cm, flesh thickness up to 7 mm, single fruit weight 200 to 400 grams, good taste, strong plant growth, strong disease resistance, and high yield.

II. Raising seedlings

Do a good job of disinfecting the seedbed and seeds, master the appropriate seedling age, and cultivate disease-free strong seedlings. Disinfect the seedbed by mixing 50% carbendazim at 8 to 10 grams per sq m with an appropriate amount of red tidal soil and broadcasting it. Soak the seeds in a 10% Na3PO4 solution for 30 minutes to prevent viral diseases, then rinse clean with water and soak for 8 to 12 hours, place under environmental conditions of 25°C to 30°C to germinate for 2 to 4 days, and sow after the seeds show white. Use plug trays for seedling raising, with peat as the substrate. After sowing, maintain the daytime temperature at 28°C to 30°C, the nighttime temperature at 18°C to 20°C, and the ground temperature at about 20°C. After the seedlings emerge uniformly, lower the temperature by about 3°C. For those not using plug trays for seedling raising, separate seedlings individually when the seedlings have 2 true leaves and 1 heart leaf. Standards for strong seedlings: plant height 18 to 20 cm, about 10 leaves, dark green leaf color, thick leaves, sturdy stems, well-developed root system, and no aging or diseased weak seedlings.

III. Land selection, fertilization, and planting

Choose a plot where fruit and vegetable crops have not been planted for 3 years, apply more than 45 tons per hectare of fully decomposed organic fertilizer, finely prepare the land, plow to a depth of 25 to 30 cm, and form ridges with a ridge spacing of 70 to 80 cm. Plant on a sunny morning, with a plant spacing of 40 cm, water promptly after planting, and it is best to cover with plastic film.

IV. Field management

1. Fertilizer and water management: after planting and recovery from transplanting and at the early fruit-setting stage, apply biological bacterial compound fertilizer at 450 kg per hectare in holes, and thereafter apply once after each harvest; from the seedling stage onward, spray foliar fertilizer once every 10 days at 150 to 300 ml per hectare, spraying 3 to 4 times continuously. After planting, water once to promote recovery from transplanting. After fruiting, water according to weather conditions and growth vigor, keep the soil moist regularly, generally watering once every 5 to 7 days, and do not water too much each time. 2. Temperature regulation: control the temperature at 25°C to 30°C during the day, not exceeding 32°C at the highest and not lower than 20°C at the lowest; control it at 16°C to 18°C at night. When light is too strong, it is best to use a shade net. 3. Pruning and vine hanging: pruning is a key measure affecting yield formation and fruit size, and is also a difference from ordinary sweet pepper management. Select and retain 2 to 3 main vine branches per plant, preferably 7 per sq m. Remove the flower buds of the first pepper and the lateral buds growing from the basal leaves as early as possible, and start retaining peppers from the 4th and 5th nodes, mainly relying on the main branches to set peppers, and thereafter remove lateral branches promptly. Lateral branches in the middle part can be pinched off after retaining 1 pepper, and each plant should always maintain 2 to 3 branches growing upward. Generally, no hilling is done, and to prevent lodging, plastic string is mostly used to hang and fix the plants. Colorful sweet pepper plants can reach more than 2 m in height, with about 20 peppers per plant. 4. Disease control: for fusarium wilt, use Kuweibike at 500 to 700 times dilution to drench the roots; for viral diseases, use Zhanyeling at 150 ml per hectare mixed with 225 kg of water; for early blight, use 40% Yisha wettable powder at 500 to 1000 times dilution.

V. Harvesting

As a special high-end vegetable variety, colorful sweet peppers have extremely strict requirements for fruit quality when marketed. Therefore, harvesting cannot be too early or too late, and the best harvest time depends on the variety. Purple varieties are harvested 70 to 90 days after planting, when the fruit stops expanding and becomes fully thick; red, yellow, and white varieties are harvested 100 to 120 days after planting, when the fruit has completely changed color. When harvesting, use scissors to cut from the connection between the fruit stalk and the plant; do not twist it off by hand, so as not to damage the plant and cause disease infection. After harvesting, handle the fruit gently, sort by size, package, and sell. Generally, the yield of colorful sweet peppers can reach more than 75 tons per hectare.