Effect of the temperature of the root environment on growth of soybean plants

Earley, E.B.; Cartter, J.L.

Effect of the temperature of the root environment on growth of soybean plants

1945

Earley, E.B. | Cartter, J.L.

The data obtained from this investigation indicate that irrespective of the light intensity or the time of year during which the experiments were conducted, root temperatures as low as 12 degrees C and as high as 37 degrees C restricted production of dry weight of Dunfield and Manchu soybean plants. In four of the five experiments, root temperature as low as 17 degrees C prevented maximum plant development. Root temperatures from about 22 degrees to about 27 degrees C appear to be most favorable for maximum dry weight production of top and roots when soybean plants are grown under a wide variety of aerial environmental conditions in the greenhouse. A rather close relationship was found between the top:root ratios throughout the temperature treatments, when the experiments are considered individually. However, when the experiments are considered collectively, it was found that the magnitude of the ratios apparently was determined largely by the light intensity of the photoperiod. The low top:root ratios were obtained under high light intensity conditions and the high ratios were obtained under low light intensity conditions. In general, the height of the soybean plants increased with increasing root temperature from 2 degrees to about 17 degrees C, remained uniform from about 17 degrees to about 27 degrees C, and decreased rapidly at 37 degrees C.

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