New systems for greenhouse management have been introduced in recent years that necessitate changes in some of the traditional methods of growing greenhouse crops. Evaporative cooling. infra-red heating, elevated levels of C0₂, and positive ventilation may each, if improperly used, result in changes in plant response that are not necessarily to the grower's advantage. When one aspect of a plant's environment is altered, it is necessary to reevaluate the total production system to bring all factors back into balance.

Woodside Nurseries Co., Redwood City, designed and installed the system involved in these studies.