Correlation and path analysis in relation to drought tolerance in rabi sorghum (Sorghum bicolor L. Moench)

Character association among various traits related to drought tolerance and direct and indirect effects of these traits on yield was carried out using 37 drought tolerant sorghum genotypes received from IIMR, Hyderabad along with three checks namely, M-35-1, CSV 22R and Phule Suchitra. A randomized block design was used with three replications and these treatments were evaluated and data pertaining to eight traits was recorded with the objective to determine character association among various traits related to drought tolerance in rabi sorghum. In present investigation there is existence of higher genotypic correlation when compared to phenotypic correlation this indicates the presence of inherent association among the characters. Studying association among the traits with each other and with yield component plays a major role in crop improvement program as yield is the dependent and complex trait which depends on various component traits. Significant and positive association was observed between grain yield per plant and other traits related to drought tolerance like third leaf area, flag leaf area, leaf area index, SPAD chlorophyll meter reading (SCMR) at 50 percent flowering, SPAD chlorophyll meter reading at physiological maturity at both genotypic and phenotypic levels, this association indicates increase in one or more of these traits results in increase in grain yield. Selection for a trait is effective when both the values of correlation and direct effect are higher and positive as this indicates its true association. In this investigation path analysis revealed at both genotypic and phenotypic level flag leaf area, SCMR at both 50 percent flowering and physiological maturity exhibited positive direct effect on grain yield there by it revealed their maximum contribution to the grain yield. Among the forty genotypes studied VJV 107, VJV 106, PEC 30, RSV 1921, RSV 1945 and RSV 1984 recorded better performance and these are considered as the superior genotypes.