A study of the environment within a plastic greenhouse and its effect on tomato production

Abstract

The purpose of a greenhouse is to maintain desirable growing conditions for plants during the different seasons of the year. The glass-covered greenhouse has been found to be suitable for this purpose through many yeara of use and improvement. It has been very popular for providing a controlled environment in which out-of-season crops can be grown and also as a research house for the study of plant growth. The sturdy construction required to support the weight of glass involves a high initial cost. With the development of plastic sheeting suitable for use as a glazing material, a new type of greenhouse has evolved. Greenhouses covered with plastic do not require the sturdy structure necessary to support glass, although a permanent construction may be used. To date the plastic greenhouse has found its greatest use as a temporary low cost structure. The possibility of growing crops intolerant of frost during the winter months in the southwestern United States where mild winters keep heating costs low, has increased interest in plastic greenhouses. Since high temperatures occur during the summer months in the Southwest, cooling as well as heating have to be provided if the greenhouse is to be operated through the entire year. This study was designed to measure the modification of the environment within a plastic greenhouse and to evaluate the growth response of tomatoes under these conditions. Studies were conducted to determine the temperatures which could be maintained in a plastic greenhouse during the summer, winter and spring seasons. The growth response of tomatoes under plastic was studied using winter and spring variety trials.