Growing bell peppers in greenhouses earns USD 40,000 per hectare

After graduating from the Vietnam National University of Agriculture, Trinh Viet Cuong from Chieng Di neighborhood, Van Son ward (Son La province), chose not to seek employment in a company or government agency but instead returned to his hometown to start a business growing sweet peppers (bell peppers), which matched his field of study.

Leveraging the ecological advantages of the hometown

Cuong shared that Moc Chau plateau, his hometown, sits at an average altitude of more than 1,000 meters above sea level, with a significant day-night temperature difference, cool weather year-round, loose and nutrient-rich soil, and a low risk of major storms, making it ideal for vegetable and fruit production. Moc Chau is also known as the birthplace of Vietnam’s dairy farming movement. Currently, local communes maintain over 30,000 dairy cows, which produce more than 700 tons of organic manure daily, a valuable resource for agricultural production.

Cuong chose to grow sweet peppers because they are a high-end vegetable with great economic value and a limited market supply. Notably, sweet peppers thrive only in areas with temperatures between 18°C and 28°C and humidity around 80%, conditions found in Moc Chau. Additionally, their firm skin allows them to be naturally stored for 5-7 days, making transportation to distant markets easier.

However, from November to January, Moc Chau often experiences dense fog, which reduces photosynthesis and affects plant growth, leading to lower yields. To overcome this challenge, Cuong partnered with Phung Van Kha, a fellow villager, to invest in building 4,500 m² of net houses to shield the crops from fog.

To avoid having to travel to Da Lat (Lam Dong) to learn from pepper-growing models, Cuong hired experts from the Vietnam Vegetable and Fruit Research Institute to provide on-site technical guidance, which he considered his tuition for hands-on training.

Intensive sweet pepper cultivation techniques

To achieve high productivity in Moc Chau and areas with similar ecological conditions, farmers should choose F1 hybrid pepper varieties, sow seeds from March to April, and transplant seedlings in April to May (when they are 30-35 days old). Before planting, the soil must be plowed, sun-dried, and weeded, with raised beds 25-30 cm high, 1-1.2 m wide, and a furrow spacing of 30-35 cm. Plants should be spaced 40 cm apart in rows, with an additional 40 cm between rows.

For each 1,000 m² of soil, apply 80-100 kg of lime, 1,000-1,200 kg of cow or organic compost, and 100–120 kg of NPK 13-13-13 + TE (or substitute with 200 kg of microbial organic fertilizer). Avoid direct contact between roots and chemical fertilizers. Manure and organic fertilizers should be composted with Trichoderma to enhance effectiveness and prevent fungal diseases. Lime should be incorporated during the soil preparation process.

When plants reach about 15 cm in height, pinch the tops to promote branching, then prune to retain two strong, disease-free stems for fruiting. When plants grow to 30 cm (20-25 days after transplanting), use trellises or strings to support branches and prevent lodging, especially during fruiting. Use an automatic drip irrigation system for 2-4 hours per day. Apply specialized NPK fertilizer through drip irrigation every three days (following expert recommendations). Regularly prune unwanted shoots and diseased or old leaves to improve ventilation, reduce pest incidence, and increase photosynthesis.

Common pests and diseases that affect sweet peppers include thrips, fungi-caused wilt, and bacterial wilt. To control thrips, grow peppers in net or glass houses and use plant protection chemicals containing Acetamiprid, Abamectin, Thiamethoxam, Carbosulfan, or Spinosad.

As there are no specific preventive sprays for fungal and bacterial wilts, integrated measures should be applied, including treating soil with lime before planting, rotating with solanaceous crops (potato, tomato, eggplant), using grafted pepper seedlings, growing in sterilized media, increasing organic compost application, and thoroughly cleaning and burning crop residues after harvest.

Other potential pests include aphids, mites, and anthracnose disease, which can be controlled using specialized pesticides. Only use chemicals the government approves for safe vegetable production and choose reputable suppliers such as Bayer or Syngenta.

Bell peppers begin flowering 40-45 days after transplanting and can be harvested 85-90 days after transplanting. Harvest when 50-70% of the fruit skin changes color from green to red or yellow (depending on the variety). Traders may request harvests earlier when fruit turns dark green and reaches full size (200-250g per fruit).

As an indeterminate crop, proper care allows plants to produce fruit continuously for 8-9 months. Note that seeds from market fruits should not be reused for the next crop.

Through these methods, Cuong’s cooperative, with 4,500 m² of greenhouses, produces and supplies more than 30 tons of sweet peppers annually, earning an income of USD 18,000, equivalent to a yield of 65 tons per hectare and a profit of USD 40,000 per hectare of cultivation (after deducting all production costs).