A. To Evarts and Mason (106) it is due to gravity
B. Metzger (1908) says it is due to tension and compression
C. Wersking and Baily, due to (1942) increase or decrease in plant hormones
D. Philips says (1940), it is due to wind
E. All of the above
Correct Answer: All of the above ✔
Last Updated: May 24, 2024