Question

"a low root/shoot ratio decreases the rate of transpiration while a high ratio increases the rate of transpiration'' what is the meaning of this line?

Answer 1

Root shoot ratio is one of the factors affecting the rate of transpiration. The absorbing capacity of root and transpiring capacity of leaf surface together decide the rate of transpiration. In presence of lesser absorption conditions by lesser root surface area as compared to leaf surface , enough water would not be available to transpire so rate of transpiration would decrease. Thus, low root/shoot ratio decreases the rate of transpiration while a high ratio increases the rate of transpiration.