PATH COEFFICIENT ANALYSIS OF BREAD WHEAT UNDER DIFFERENT SEEDING RATES

Abstract

A field experiment was carried out in the field of Crop Science Dept., Coll. of Agric. Univ. of Baghdad during 2011/2012 winter season to study the path analysis for some quantitative traits in bread wheat. The experiment was conducted as randomized complete block design with four replication using a split plot treatment arrangement where three seeding rates (120, 160, and 200 kg/ha) randomized in the main plots and 21 genotypes in the sub-plots. Path analysis was performed using genotypic correlation considering grain yield as the response variable and number of days to anthesis, plant height, flag leaf area, number of spikes per square meter, number of grains per spike, and grain weight as independent variables. Path coefficient analysis revealed that the magnitude of positive direct effect on grain yield was highest through number of spikes/m2, followed by grain weight and grains per spike; whereas plant height exhibited high, but negative direct effect on grain yield. There was negative indirect effect of number of spikes/m2 via grain weight. These results indicated that grains per spike and number of spikes/m2 along with their indirect causal factors should be consider simultaneously as an effective selection criteria to isolate superior genotypes from genetically mixed populations to develop higher yielding varieties due to positive association and direct effects of these traits on grain yield.