LEAF AREA IN GRASS CEREALS IN RELATION TO LEAF PARAMETERS; CASE STUDY IN WHEAT

Abstract

The study determined values of the correction factor (CF) for four wheat cultivars, in order to determine with greater accuracy the leaf surface by the non-destructive method, based on leaf parameters (length, width). The wheat cultivars Ciprian, Dacic, Glosa and Padureni were considered in the study. The plant samples came from cultures made within SCDA Lovrin, Romania. For each wheat cultivar, 100 leaf samples were taken (flag leaf). The dimensions of the leaves (length – L, width – w) were obtained by measurement (±0.5 mm). By scanning, the scanned leaf surface (SLA) was obtained. The values of the correction factor were obtained by calculation (CF=0.79 for Ciprian cultivar; CF=0.80 for Dacic cultivar, CF=0.78 for Glosa cultivar; CF=0.79 for the Padureni cultivar). The leaf area was calculated with high precision for each wheat cultivar, as a relationship between L, w and CF (RMSEP=1.32042 for Ciprian cultivar; RMSEP=2.41317 for Dacic cultivar; RMSEP=2.21665 for Glosa cultivar; RMSEP=1.30141 for Padureni cultivar). The fit between MLA (measured leaf area) and SLA (scanned leaf area) was described by linear equations, with the highest precision in the case of the Padureni wheat cultivat (R²= 0.933), a cultivar in whose case the RMSEP value also confirmed the higher precision for calculating the MLA. The correlation analysis on the series of data related to each wheat cultivar studied, highlighted various levels of correlations, in conditions of statistical safety. The correlation analysis on the entire data series (400 values) highlighted very strong negative correlations between the calculated ratios (r=-0.977 between L/w and w/L) and very strong positive correlations at the leaf area level (r=0.920 between MLA and SLA). High variability was recorded in the case of MLA for the Ciprian cultivar (CV_MLA=19.61861) and for the Padureni cultivar (CV_MLA=27.07106), in the case of SLA for the Dacic cultivar (CV_SLA=22.72838), and Glosa cultivar (CV_SLA=18.52030).