1Division of Floriculture and Landscaping, Indian Agricultural Research Institute, New Delhi, 110 012
2Department of Agricultural Engineering and Food Tcchnology, Sardar Vallabh Bhai Paid University of Agriculture and Technology, Mecrut, Uttar Pradesh, 250110
3Indian Council of Agricultural Research, Krishi Anusandhand Bhavan-11, Pusa, New Delhi, 110 012
4Section of Agricultural Engineering, Indian Institute of Horticultural Research, Hessaraghatta Lake Post Office, Bangalore, Karanataka, 560 089
Temperature and humidity variations have been observed for naturally ventilated and fan pad-cooled greenhouses in comparison to ambient conditions for a period of one year under Bangalore climatic conditions. Performance of gerbera crop has been monitored in the two greenhouses and linked to the greenhouse temperature and humidity conditions. Seasonal average temperatures in the naturally ventilated greenhouse were generally close to the ambient air temperatures and were higher by about 0.5 - 1.6 "C only. Relative humidity of naturally ventiated greenhouse was close (within 5%) to the ambient relative humidity, whereas in case of fan - pad cooled greenhouse, the greenhouse temperatures were 3 -4 "C lower than ambient during summer months. At other times of the year, the temperatures in fan - pad cooled greenhouse were 10 - 30% higher than ambient air values. The crop performance in naturally ventilated greenhouse was observed to be superior to that in the fan - pad cooled greenhouse. Higher relative humidities in fan - pad cooled greenhouse appear to be responsible for higher disease incidence and consequently poorer crop performance.
Fan-pad cooled greenhouse, gerbera, humdity, naturally ventilated greenhouse, temperature
