Most of the literature on growth and reproduction in plants leaves the implication that cessation of vegetative activity in plants of an indeterminate type of growth is due to the drain of nutrient materials imposed on the plant by the developing fruits. This is not true for the soybean. The variety used in this investigation flowers early and continues to grow for some time afterward and appears to cease growing as the fruits mature. However, plants from which the flowers are continuously removed increase in percentage of dry weight at the same rate as the controls and stop growing at the same time. A very large reserve of carbohydrates accumulates in the stems of exflorated plants and is nearly equal to the total amount in the control plants plus their fruits. The controls assimilate much more nitrogen and minerals than the exflorated plants so that the development of fruits does not greatly lessen the amounts of these substances in the vegetative parts of the plants. Maturity of the soybean plant may result from some indirect effect of the length of day or possibly to some growth inhibiting substance secreted by the flowers, but it is certainly not due to the diversion of nutrient materials to the developing fruits.
Proceedings of the Iowa Academy of Science
©1933 Iowa Academy of Science, Inc.
"The Effects of Exfloration on the Soybean,"
Proceedings of the Iowa Academy of Science, 40(1), 75-76.
Available at: https://scholarworks.uni.edu/pias/vol40/iss1/13