The change in the specific leaf area of maize grown under Mediterranean conditions

Summary — The change in the specific leaf area (ie the leaf area per dry matter weight unit) of 2 single maize hybrids was studied in 4 field experiments carried out in central and northern Greece in 1987 and 1988. It was found that the overall specific leaf area of maize takes an initial value much lower than the values suggested for central European conditions and decreases as a function of the development stage of the crop, independent of location, cultivar, plant density (within the normal range), soil conditions, irrigation management and crop growth. A methodology for calculating the development stage based on the accumulated thermal units method is also discussed. Further, the validity of the produced empirical relation between specific leaf area and development stage was tested for 13 more maize plantings grown in western Greece in 1991. A fairly good agreement with the measured values especially before flowering (end of leaf growth) was found, suggesting that the empirical relation may be used in modern crop growth models simulating maize growth under Greek and more generally Mediterranean conditions.