Abstract

                                Three low cost greenhouses of size 8x4 m each with ridge heights of 3m, 3.75m and 4.5m were designed and constructed with a side and roof ventilation of 30% and 6% respectively. The light intensity inside the greenhouses were found to be much lower than that of outside. The rate of reduction of light intensity inside the greenhouses was found to increase with increase in light intensity. It was observed that, during peak hours (at which light intensity was maximum), lower amount of light intensity was received by the 4.5 m height greenhouse and it was found to increase with decrease in height of the greenhouse. The 3 m and 3.75 m and also 3.75 m and 4.5 m greenhouses were on par in respect of light intensity even at 10% level. But, there was a significant reduction (P < 0.01) of light intensity in 4.5 m greenhouse compared to the 3 m greenhouse.

Key words : Greenhouse, height, temperature, light intensity