Show simple item record

dc.contributor.advisorRunkles, J. R.
dc.creatorNamken, Leo Neal
dc.description.abstractRadical changes of cotton plant stems were monitored throughout the 1969 and 1970 crop seasons under field conditions using linear variable displacement transducers. The absolute amount of stem contraction from the 0600 hr condition was closely related to the relative water content of the cotton leaves during stress cycles. The water potential of cotton leaves was closely related to the amount of stem contraction during the desorption phase of the stress cycle. Hysteresis confounded the relation during the absorption or recovery phase of the stress cycle. The data indicate that the degree of cotton stem contraction is directly related to the water potential gradient established in the water conducting tissues of the stem due to an imbalance between transpiration and absorption rates. Plant water stress, in term of radical change measurements, was closely associated with changing soil moisture tension and solar radiation conditions. A response in the radical change measurement was consistently detected within 8 to 10 minutes of a sudden change in radiation flux density due to the passing of a cloud, thus indicating that plant water stress is very dynamic, changing rapidly with changing environmental conditions. The rate of radical change vs cumulative radiation up to midafternoon increased with increasing mean soil moisture tension. It is postulated that these rates (radical change (mm) per ly incident radiation) reflect the imbalance between transpiration and absorption thus provide a measure of the capacity of the soil to supply water to the roots under the existing atmospheric conditions..en
dc.format.extent90 leaves : illustrationsen
dc.rightsThis thesis was part of a retrospective digitization project authorized by the Texas A&M University Libraries. Copyright remains vested with the author(s). It is the user's responsibility to secure permission from the copyright holder(s) for re-use of the work beyond the provision of Fair Use.en
dc.subjectSoil Physicsen
dc.subject.classification1970 Dissertation N174
dc.titleEvaluation of the quantitative relation between diurnal fluctuations in stem radius and water stress of cotton plants under field conditionsen
dc.typeThesisen Physicsen A&M Universityen of Philosophyen
dc.contributor.committeeMemberBurnett, E.
dc.contributor.committeeMemberGerard, C.
dc.format.digitalOriginreformatted digitalen
dc.publisher.digitalTexas A&M University. Libraries

Files in this item


This item appears in the following Collection(s)

Show simple item record

This item and its contents are restricted. If this is your thesis or dissertation, you can make it open-access. This will allow all visitors to view the contents of the thesis.

Request Open Access