The thermoelectric method was used to determine the effect of external conditions and diurnal variation on the direction of xylary fluid movement in elm branches. Upward movement was detected under conditions favoring normal transpirational rates. No movement was detected during darkness or rainy conditions. Possible downward movement of branch fluid was indicated during late afternoon. Further refinement of the technique is needed for clarifying the latter observation.
Proceedings of the Iowa Academy of Science
©1962 Iowa Academy of Science, Inc.
McNabb, Harold S. Jr. and Hart, John H.
"Measurement of Xylary Fluid Movement in Elm by the Thermoelectric Method,"
Proceedings of the Iowa Academy of Science, 69(1), 132-137.
Available at: https://scholarworks.uni.edu/pias/vol69/iss1/20