CALCULATION OF TRANSLOCATION COEFFICIENTS FROM PHLOEM ANATOMY FOR USEIN CROP MODELS

Translocation coefficients, computed for unit ground area, are require d in crop models as part of the simulation of the partitioning of assi milates. An equation for translocation is derived by considering press ure-driven flow and the physical dimensions of the pathway in the phlo em. Numerical estimates of the translocation coefficients for grasses and trees are calculated using anatomical data. The values found are c ompatible with published rates of translocation in the phloem. (C) Ann als of Botany Company