Went • The Role of the Environment in Pkmt Growth 99 



F. W. Went 



The Role of the Environment in Plant Growth 



Reprinted with the permission of the author 

 and pubhsher from American Scientist 44(4) : 

 378-398, 1956. 



Among the many problems facing very broadly, and can be subdivided 



the biologist perhaps none looms as into internal and external environment, 



large or seems as elusive as the how and The internal environment for gene ac- 



why of organic form and function, tion is the cell and its physical and 



There are many possible approaches chemical make-up. The cell itself is 



toward a solution of these problems, definitely also a gene product, filtered 



In the following article I want to show already through the modifying influ- 



to what extent an analysis of the effects ence of the external environment, as 



of environment can contribute to an far as temperature, radiation, and sur- 



understanding of the living plant. But rounding cells are concerned. The ex- 



in addition to being a tool in solving ternal environment for the developing 



problems of growth and development, plant consists of the soil, the surround- 



the investigation of environment in ing air, radiation in all its forms and 



connection with plants is an end in manifestations, numerous pests, dis- 



itself, and gives us an insight into plant eases and viruses, the physical and 



distribution and may become an impor- chemical effects of neighboring plants, 



tant factor in agricultural production, and many other factors. Among the 



A fertilized egg-cell or zygote con- latter, man looms large, both through 



tains in its hereditary make-up the full his direct and indirect influences, 

 potentialities to develop into a mature Most of the factors of the external 



plant. Yet the exact size and shape of environment of the plant have been 



this plant are not predetermined; they under intensive investigation for scores 



are conditioned and modified by the of years, largely because they are of 



environment in which the zygote de- paramount importance to man in his 



velops. This is usually expressed by say- efforts to make the plant cover of the 



ing that the mature plant is the product earth subservient to his needs. Tliis has 



of the interaction between its genes and led to the development of Plant Pa- 



the environment: a modification of thology, Parasitology, Soil Science, Agri- 



either will influence the end-product, culture, Horticulture, Forestry, Plant 



The environment can be considered Nutrition, Irrigation, and many other 



