Genotypic and Phenotypic Correlations among Yield and Yield Components in Durum Wheat (Triticum durum Desf.) under Different Water Treatments in Eastern Algeria

The present study was conducted on the experimental site of ITGC (Technical Institute of Field Crops) station of Setif, Algeria; during 2010/2011 cropping season. The study was carried out to study the performance of durum wheat genotypes in relation to yield and yield component and evaluate genotypic and phenotypic correlations between yield and yield components under different water deficit conditions. Three irrigation treatments were obtained by irrigation at specified stages and no irrigation. These treatments were: no irrigation during all growth stages (I0); 20 mm irrigation during vegetative plant growth (Tillering stage) (I1) and 40 mm irrigation during reproductive plant growth (heading stage) (I2). Analysis of variance revealed that number of spike per m-2 (NS m-2) and grain yield (GY) were very significant (P < 0.001) affected under irrigation regime treatment whilst number of grain per spike (NG S-2) was shown highly significant (P <0.01). Grain yield reductions were 6 %, 12.4 % under the I1 and I0 treatments respectively, when compared with the optimum irrigation treatment (I2). Water limitation decreased NS m-² by 14.11% and 9.67 % in the I0 and I1 treatments compared to the I2. Water limitation decreased NS m-² by 14.11% and 9.67 % in the I0 and I1 treatments compared to the I2. Grain yield showed significant and positive genetic and phenotypic correlation with number of spikes per meter square (NS/m²) under all conditions of growth. Harvest index and number of grains per meter square showed significant genetic and phenotypic correlations with grain yield under rainfed and irrigated conditions. The differential response of cultivars to imposed water stress condition indicates the drought tolerance ability of wheat cultivars. The significant genetic and phenotypic correlations among grain yield and yield components suggest that grain yield could be effectively increased by maximum genetic expression of grains spike-1, number of spikes per meter square, number of grains per meter square and harvest index.