THE CHANGE IN THE SPECIFIC LEAF-AREA OF MAIZE GROWN UNDER MEDITERRANEAN CONDITIONS

The change in the specific leaf area (ie the leaf area per dry matter weight unit) or 2 single maize hybrids was studied in 4 field experime nts carried out in central and northern Greece in 1987 and 1988. It wa s found that the overall specific leaf area of maize takes an initial Value much lower than the values suggested for central European condit ions and decreases as a function of the development stage of the crop, independent of location, cultivar, plant density (within the normal r ange), soil conditions, irrigation management and crop growth. A metho dology for calculating the development stage based on the accumulated thermal units method is also discussed. Further, the validity of the p roduced empirical relation between specific leaf area and development stage was tested for 13 more maize plantings grown in western Greece i n 1991. A fairly good agreement with the measured values especially be fore flowering (end of leaf growth) was found, suggesting that the emp irical relation may be used in modern crop growth models simulating ma ize growth under Greek and more generally Mediterranean conditions.