Size of Passive Solar Greenhouse Determine Growth and Yield of Cauliflower and Cabbage During Winter in High Mountain Ladakh Region, India

The length and span of passive solar greenhouse are important factors that determine greenhousemicroclimate. However, there are no established length and span recommendations for guiding construction of passive solar greenhouse in high altitude regions, especially above 3000 m asl. Majority of the farmers in trans- Himalayan regions have preference for low-cost small size (<10 m length) passive solar greenhouses. We studied two different sized greenhouses and found that a large greenhouse (27.4 m length, 8.2 m width) was better than a small greenhouse (9.8 m length, 5.5 m width) for growing cauliflower and cabbage in winter. The large greenhouse remained 1.5±0.3 to 7.4±2.1 °C warmer during daytime, and 0.6±0.1 to 1.5±0.8 °C warmer at night. All the recorded plant growth parameters were higher in the large greenhouse. The mean marketable weight of cauliflower cv. Shantha was 599±35 g in the large greenhouse as against 537±42 g in the small greenhouse. Similarly, the marketable weight of cabbage cv. Golden Acre in the large greenhouse was significantly higher (619±53 g) than the small greenhouse (523±121 g). Therefore, large passive solar greenhouses are recommended for farmers in high altitude trans-Himalayan Ladakh regions.