Effect Of Supplemental Irrigation On Reflectance And Some Physiological Properties Of Durum Wheat (triticum Durum Desf.)

The present study was led on the experimental site of ITGC (Technical Institute of Field Crops) station of Setif, Algeria during the 2010/2011cropping year. The objective of this study is to evaluate the effect of irrigation on reflectance at Red and Blue and its relationships with grain yield, chlorophyll content and senescence parameters under irrigated and non irrigated conditions. The reflectance and senescence are measured using the numerical image analyses (NIA) and chlorophyll content (CC) is measured by SPAD instrument. Analysis of variance revealed that the reflectance at different wavelengths (Red and Blue) was highly significant (P < 0.001) affected under irrigation regime treatment. In addition, the genotypic effect was shown highly significant for the reflectance at Red and Blue under two conditions. In both conditions (irrigated and non irrigated), the genotype effect was highly significant for grain yield and chlorophyll content. The difference between grain yield under stressed and non-stressed conditions equal 12.42%. In this study, the stress intensity (SI) equals 14.72 %. Achieved results from calculation of drought tolerance and drought sensitive indices show that MP, GMP and STI, having higher values indicated stress tolerance consider that Waha, Dukem and Sooty genotypes with yields of 64.63, 63.94 and 63.14 Qx ha-1 respectively as stress tolerant genotypes. Grain yield showed a significant and negative correlation with reflectance at Red (r = -0.70); this correlation suggest that the decrease in the photosynthetic capacity of the canopy increase leaf reflectance at Red because the Red light is the major radiation absorbed by chlorophyll pigments. The significant correlation between reflectance at Red and Blue and drought resistance indices suggest the efficiency of using the reflectance at Red in screening under drought instead of the drought resistance indices.