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Jiping Zhu

Document Type

Thesis - University Access Only

Award Date

1991

Degree Name

Master of Science (MS)

Department / School

Agricultural Engineering

First Advisor

Ralph Alcock

Abstract

An instrument which will continuously monitor root growth rate and apply different axial forces at the root tip was designed and constructed. Corn seedlings were studied with this device. The axial root growth rate was significantly reduced when an axial force of ten grams was applied at the tip. Changes in root diameter were also determined. The ratio of final root diameter to initial root diameter increased with applied load at the root tip and then tended toward a constant value of approximately 1.4 at loads greater than eight grams. These changes occurred within the elongation zone. A ten gram load was found to reduce to 37 percent, and increase the root diameter ratio to 99 percent, of those at zero gram force. The corresponding pressure at ten gram load was 56.5 kPa. The maximum growth force and pressure values were much smaller than. those previously reported. A new root growth model was also proposed based on this study. The root diameter [sic] in the elongation zone increased or decreased with the change of the applied force at the root tip. The dimension of the meristematic zone and the root cap remained [sic] constant for different laods. [sic]

Library of Congress Subject Headings

Roots (Botany) -- Growth -- Effect of stress on
Mechanical impedance

Format

application/pdf

Publisher

South Dakota State University

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