Leafy green vegetables, such as brassicas, kangkong, lettuce or spinach, are popular around the world and especially in Asia because of their quick-growing crops within four to six weeks. These vegetables are valuable sources of vitamins A and C, iron, calcium, folic acid, and dietary fiber.
In the past, all leafy vegetables were grown in open fields and effectively controlled with pesticides against insects and pests. The general public was much less concerned of the danger of pesticide contamination in their food and the environment. But conditions have changed during the past 10 years as consumers are becoming more conscious of their personal health and the quality of the environment. Hence, safer methods of pest control have to be found.
A net-house installation procedure has been studied and tested by Asian Vegetables Research and Development Center for the purpose of preventing entry of all damaging insects inside the net houses, thereby, enhancing the effectiveness of the structure and reducing the need to use pesticides. In fact, over the past two years, the organization have cultivated 15 cycles of various leafy vegetables—free of any pesticide use—without loss of yield or quality of the product outcome.
Summary of key points for net houses
- Choose an elevated and well-drained area for construction of net house.
- Flood the area so that 15 to 25 cm of water stands continuously for four to seven days.
- Drain the field, allow the soil to dry, and construct the net house without delay.
- Use 32-mesh nylon netting that is uniformly weaved and of durable quality.
- A double door with two sliding panels is adequate, but an arrangement of two double doors at right angles to each other is best.
- Keep the net house tightly sealed at all times.
- Rotate crops chosen from different plant families to reduce pest and disease problems.
- Monitor crops closely and use pesticides only when absolutely necessary. Follow local recommendations and safety instructions carefully.
- After harvest, clean soil of all debris.
- Maintain the cleanliness and integrity of the netting.
For full document, you can download here: Net House