Retractable roof greenhouse: Potential for Solanaceae production in semi-arid regions.

Abstract

Retractable Roof Greenhouses are a new trend in the greenhouse industry. They allow the improvement of many nursery and crop production practices in semi-arid regions. Hydroponically grown peppers and tomatoes were tested to evaluate possible year-round cultivation in this kind of structure that permits high radiation exposure. Control systems based on radiant surfaces temperatures were developed to integrate, cost effectively, the environmental factors that influence the plants' development and yield, including: air temperature, solar radiation and wind speed. Yields of 7.4 kg m⁻² and 33.0 kg m⁻² were obtained respectively for top quality pepper and tomatoes. These yields were similar or slightly lower than conventional greenhouses in the similar price range and design complexity. This makes the retractable roof greenhouse a mediocre structure for pepper and tomato production in southern Arizona. Radiant surface temperature was found to be a useful parameter for the control of the retractable roof greenhouse climate.