Field Studies of Cereal Leaf Growth

Abstract

Destructive measurements of laminar, sheath, and internode length made on spring barley and winter wheat enabled the contribution of these phytomer components to apparent leaf extension rate (R_E), as measured by auxanometer or rule, to be determined. R_E for early formed leaves consisted entirely of laminar and sheath extension. However, during stem extension, internode extension also contributed to measured R_E. For the last two leaves of winter wheat, the extension of internode below the phytomer being measured contributed to R_E. For these leaves, R_E should therefore be interpreted cautiously. Calculating main stem and tiller leaf areas, and allowing for changes of leaf width with leaf number, showed that leaf extension was closely related to crop leaf area expansion.