Issues in Protected Horticulture

a. High Initial Investment

• The construction of polyhouses, naturally ventilated greenhouses, and glasshouses requires significant capital investment. Example: Farmers in Kavre and Chitwan struggle to invest in high-tech tunnels for strawberries and tomatoes.
• Lack of funds limits adoption among small-scale farmers.
• Imported materials (e.g., UV-resistant plastics) further increase costs.

b. Operational and Maintenance Costs

• Continuous electricity consumption for fans, heaters, and lighting raises costs. Example: Heating strawberry tunnels in Dhading during winter is expensive.
• Regular replacement of plastic covers, nets, and substrates adds to expenses.
• Maintenance of drip irrigation and climate-control systems requires skilled labor.

c. Pest and Disease Problems

• Protected environments may favor rapid pest and disease spread. Example: Whitefly in tomato polyhouses or powdery mildew in cucumber tunnels.
• Integrated pest management is needed to reduce chemical use.
• Pests can be hard to monitor in dense crop planting.

d. Water Management Issues

• Over-irrigation can cause root rot and waterlogging; under-irrigation reduces yield. Example: Tomatoes in greenhouse hydroponics require precise drip irrigation.
• Salinity buildup in reused water can affect crop growth.
• Mist and fog systems need careful calibration to avoid excessive humidity.

e. Crop and Variety Limitations

• Only high-value vegetables, fruits, and ornamentals are economically viable. Example: Lettuce, capsicum, cucumber, and strawberry are commonly grown; mango or guava are unsuitable.
• Limited crop rotation can increase soil-borne disease risks.
• Farmers may lack access to improved cultivars suitable for protected cultivation.

f. Technical Expertise Requirements

• Skilled labor is needed for temperature, humidity, and nutrient management. Example: Improper humidity control in strawberry tunnels can lead to fungal infections.
• Lack of training can result in low yield and poor quality.
• Hydroponics and aeroponics require understanding of nutrient solution management.

g. Energy Dependence

• High reliance on electricity or fossil fuels for heating, cooling, and ventilation. Example: Tomato polyhouses in Terai require fans during summer, heaters in winter.
• Energy outages can stress plants, reducing productivity.
• Solar-powered or biomass systems are not yet widely adopted due to cost.

h. Pollination Challenges

• Enclosed environments reduce natural pollinator activity. Example: Manual pollination in cucumber and bell pepper greenhouses.
• Poor pollination can reduce fruit set and quality.
• Bee hives or artificial pollination increases labor costs.

i. Environmental Concerns

• Disposal of plastic covers, nets, and substrate waste can pollute the environment. Example: Old polyhouse plastics discarded in Chitwan or Nuwakot create waste management issues.
• Excessive use of chemical fertilizers and pesticides can contaminate soil and water.
• Energy-intensive systems increase the carbon footprint of production.

j. Market and Socioeconomic Issues

• Dependence on market access and price fluctuations affects profitability. Example: Sudden drop in strawberry prices in Kathmandu Valley markets affects small-scale growers.
• Limited awareness among farmers about marketing and export opportunities.
• High input costs can discourage adoption among rural and smallholder farmers.