W. L. Bauerle, Ted H. Short
Plant culture must be adjusted for most energy conservation systems to produce optimum plant yields and quality. Double glazing is the most typical technique for modifying an existing greenhouse. The most obvious environmental change is usually associated with light reduction, but other factors such as temperature, humidity, and CO2 can also be altered. Reducing infiltration will reduce the available CO2 if CO2 is not supplemented. If CO2 is supplemented, much higher than previous acceptable levels are attainable. Also, lower light levels will allow CO2 to be supplemented longer before ventilation is required. Sealing glass can increase the amount of dripping, but the air humidity will not necessarily change. Less heat loss almost always results in better night temperature control. All these changes in environment can be used advantageously for high productivity. If these factors are not understood, growers can make serious cultural mistakes that reduce plant yield and quality.

For low light winter conditions, white plastic reflective mulches have been shown to increase plant growth response. Optimum air and soil moisture conditions for plant growth can be achieved by altering the irrigation methods. With less outside air infiltration in energy efficient closed greenhouses, enrichment with carbon dioxide (CO2) is a necessity.

Bauerle, W. L. and Short, Ted H. (1981). CHANGES IN PRACTICES FOR ENERGY CONSERVATIVE GREENHOUSES. Acta Hortic. 115, 309-310
DOI: 10.17660/ActaHortic.1981.115.33

Acta Horticulturae