Challenges in Protected Horticulture

a. Economic Challenges

• High initial investment for structures like polyhouses is seen in Kavre or Chitwan.
• Operational costs for electricity for fans/heaters in tomato and cucumber greenhouses.
• Market dependency: Price drop in strawberries or bell peppers affects profitability.
• Limited access to financial support in remote areas like Dolakha and Ramechhap.

b. Technical Knowledge and Skill Requirements

• Skilled labor needed for drip irrigation in tomato cultivation.
• Mismanagement of humidity in strawberry tunnels can lead to fungal diseases.
• Lack of knowledge in nutrient management in hydroponics of lettuce reduces yield.
• Understanding crop-specific requirements like temperature control for capsicum is essential.

c. Climate Control Challenges

• Maintaining optimal temperature during winter in Kathmandu Valley greenhouses.
• Ventilation issues in naturally ventilated polyhouses during monsoon can cause leaf diseases.
• Rapid fluctuations in microclimate stress crops like cucumber and tomato.
• Dependence on automated fans and heaters for crops like bell pepper in high-altitude farms.

d. Pest and Disease Management

• Aphid outbreaks seen in strawberry tunnels.
• Rapid spread of powdery mildew in cucumber polyhouses.
• Limited chemical control: use of biopesticides like Trichoderma for tomatoes.
• Continuous monitoring required for whitefly in capsicum cultivation.

e. Water Management Issues

• Over-irrigation causing root rot in tomatoes grown in greenhouses.
• High water requirement for cucumber tunnels during summer.
• Technical expertise needed for mist irrigation in lettuce hydroponics.
• Water quality affecting crops: salinity issues in polyhouse bell peppers.

f. Crop Selection Limitations

• Not suitable: large fruit trees like mango or guava in polyhouses.
• Suitable high-value crops: tomato, capsicum, cucumber, lettuce, and strawberries.
• Limited crop rotation: cucumber followed by tomato in tunnels.
• Focus on high-value crops reduces diversification in areas like Chitwan greenhouses.

g. Energy Dependence

• Heating costs for strawberry tunnels in winter in Dhading.
• Cooling fans for tomato polyhouses during hot Terai summers.
• Energy outages affecting bell pepper and tomato production in remote Kavre farms.
• Investment in solar panels for sustainable energy in hydroponic lettuce farms.

h. Infrastructure and Maintenance Challenges

• Greenhouse covers in plastic tunnels in Jhapa degrade after 3–4 years.
• Maintenance of shade nets in strawberry farms in Nuwakot.
• Substrate replacement in hydroponics for lettuce cultivation.
• Structural damage during storms affecting cucumber polyhouses in Terai.

i. Pollination Limitations

• Strawberries require manual pollination in high tunnels.
• Cucumber and capsicum may need hand pollination or bee hives.
• Poor pollination reduces fruit set in bell peppers in Kathmandu Valley greenhouses.
• Additional labor needed for artificial pollination in hydroponic tomato cultivation.

j. Environmental and Sustainability Concerns

• Disposal of used plastics from polyhouses in Chitwan.
• High energy use in heated strawberry tunnels contributes to carbon footprint.
• Overuse of fertilizers in tomato and capsicum polyhouses can cause soil degradation.
• Implementation of water recycling in hydroponic lettuce systems reduces waste.