A procedure for the study of the negative geotropic response in the Coleus stem and Avena coleoptile is presented. Time-lapse photography, employing a motordriven 35mm camera and specially designed chambers, is utilized in recording plant responses. Data from 3" x 7" photographic prints are recorded on computer punch cards, a line of best fit is determined and the rate of geotropic curvature at forty-five degrees calculated. This unique technique of reporting curvature rates emphasizes the dynamic character of the geotropic response and eliminates variation involved in the plant's perceptive mechanism.
Proceedings of the Iowa Academy of Science
©1970 Iowa Academy of Science, Inc.
Granger, Charles R.
"A Method for the Dynamic Evaluation of the Geotropic Response,"
Proceedings of the Iowa Academy of Science, 77(1), 38-46.
Available at: https://scholarworks.uni.edu/pias/vol77/iss1/9