The influence of leaf position (age) on the shoot on stomatal conductance and depth on xylem flow rate in apples (Malus pumila) MM106 cv. Gala branches were studied at Lincoln University Canterbury, New Zealand. Leaf position on the shoot had significant effect on the stomatal conductance. Old leaves had a higher stomatal conductance (gs) 0.53 (mol H2O m -2 s -1 day -1 followed fully expanded new leaves with 0.48 (mol H2O m -2 s -1 day -1 as compared to that for new (not fully expanded) leaves which was 0.20 (mol H2O m -2 s -1 day -1. However, the apical positions exhibited rapid changes in gs while the intermediate leaves exhibited somewhat uniform changes in gs through out the day. A progressive decrease in xylem flow was measured across the branches of apple trees. The highest xylem flow was at 7.5mm depth from the surface of bark.
G. Nabi , M. C. Trought , R. Noor and A. Samad , 2000. To Study Stomatal Conductance at Different Leaf Positions and Xylem Flow Rate
at Different Depths in the Apple Branch . Pakistan Journal of Biological Sciences, 3: 1634-1636.