The sweet pepper (Capsicum annuum L.) is an annual plant belonging to the Solanaceae family. The root system is a highly branching one, located in the 20–30 cm soil layer. The regenerative capacity of the pepper root system is low. The stem is herbaceous early in the growing season and lignified at the base by the time of fruit maturation.
Sweet pepper has high requirements for temperature. The minimum germination temperature is 14–15˚Ñ; at 13˚Ñ no germination occurs and plant growth is terminated. Under favorable conditions, emergence occurs 10–15 days after sowing. The optimum germination temperature is 24–30˚Ñ and the optimum growth temperature is 22–25˚Ñ.
Sweet pepper is sensitive to light. Growing seedlings in low light conditions has an unfavorable effect on plant development.
Soil and air humidity are among the factors essential for optimum growth and development of pepper plants. The optimum soil moisture content is 70–75 % of field moisture capacity prior to fruiting and 80–85 % of field moisture capacity during fruiting.
Sweet pepper grows well on light, permeable and fertile soils which are readily warmed up. On cold, heavy soils, sweet pepper plants exhibit poor growth and are severely affected by Verticillium wilt.
Growing tips
The best preceding crops are annual legumes, cabbage, cucumber and grain crops.
The principal growing technique is by transplanting. The age of seedlings to be transplanted should be 35–65 days. The output of seedlings is 270–450 plantlets (up to 1000 plantlets when cassette-grown) per 1 m2 of greenhouse area. The transplanting is performed when there is no longer risk of spring frost, at air temperatures not lower than 13–15˚Ñ and the soil temperature of 10–12˚Ñ. The recommended plant density is 30,000–50,000 pl/ha. The planting pattern is 70 õ 30–50 cm. The seeding rate is 0,5–1,0 g per 10 m2 of open ground.
Where high yields of sweet pepper are desirable, it is good practice to apply organic fertilizers at a rate of 40–50 kg per 10 m2 (40–50 ton/ha) and nitroammophoska at a rate of 1000 g per 10 m2 (N 160, P2O5 160, K2O 160 kg of active substance per hectare). The organic and 2/3 of the mineral fertilizers are applied with autumn plowing, the balance of the mineral fertilizers being applied as supplementary fertilizing during the growing season. The fertilizer application rates are adjusted according to the soil nutrient status data. Sweet pepper being highly sensitive to chlorine-containing fertilizers (potassium salt, potassium chloride), potassium sulfate or other chlorine-free fertilizers are normally used. Sweet pepper has high magnesium requirements. Soil magnesium deficiency may result in exfoliation, a drop in yield and lower fruit quality. It is advisable to apply magnesium in the form of magnesium sulfate at a rate of 500–600 g per 10 m2 (Mg2O 80–100 kg of active substance per hectare).
Sweet pepper has very high moisture requirements. Both deficiency and excess of moisture cause blossoms, buds and ovaries to fall off. Sweet pepper plants are given 8 to 13 irrigations, the rate of water application being 350–400 l per 10 m2 (350–400 m3/ha) per irrigation. In hot weather, the plants should be irrigated every 5–7 days. Combining drip irrigation with application of water-soluble fertilizers through the drip irrigation system (fertigation) is a highly efficient technique resulting in a more uniform moisture and fertilizer distribution in the root zone, more efficient water use, less soil compaction, and no soil crust formed. Readily soluble mineral fertilizers are given with each water application.
The most important diseases: Verticillium wilt, Macrosporium leaf spot, Bacterial black spot, and Big bud (stolbur) of pepper.
Control measures: strict adherence to the crop rotation program, good cultural practices, extermination of sucking-insect vectors, and sprays with fungicides such as Cuproxat, Acrobat MC, etc.
Major pests: aphids, cutworms, and thrips. The insectiacaricides Kelthane, Danitol and Talstar are used to control the spider mite; Zolone, Fury, Sherpa and other insecticides are used to control the cotton-ball worm.