Effect of waste and fresh-water irrigation on barley (Hordeum vulgare L.) yield traits using principal component analysis
A field experiment was conducted at the experimental farm of the Agricultural Experimental and Research Station (Derab), Faculty of Food and Agricultural Sciences, King Saud University, near Riyadh, Saudi Arabia, during 2014/2015. Ten varieties of barley were evaluated under two different irrigations freshwater (W1) and wastewater (W2). Statistical analysis showed the significant differences among the varieties, irrigation treatments, and varieties × irrigation for all the measured traits. Mean performance of plant height, number of tillers/plants, spike length, number of spikes/plant, 1000-grain weight, single spike weight, grain yield/plant was a significant increase under wastewater irrigated than freshwater as a grand mean of all genotypes. The grain yield/ plant showed a highly significant and positive correlation with plant height, number of tillers/plant, number of spikes /plant, 1000- grain weight and single spike weight under wastewater. The PC1 explained 40.469 and 38.632% of the obtained variation and the PC2 explained 78.132% and 69.793% under fresh and wastewater irrigation respectively. The cluster analysis for wastewater irrigation assigned the genotypes into two main clusters; the first cluster consisted of 6 genotypes (G5, G1, G7, G10, G6 and G2) and represented 60% of the total genotypes.