| Correlation and path analysis in wheat under high temperature
and moisture stress conditions N.N. PATHAK, D.P. NEMA and P.V.A. PILLAI J.N.KRISHI VISHWA VIDYALAYA, Zonal Agricultural Research Station Powerkheda 461110, India Rainfed wheat in India is generally sown in later part of October to avoid high temperature at the early growth stage (HOWARD 1924) while monsoon recedes by later part of September. During this intrim period, the soil looses moisture which adversely affects germination resulting drastic reduction in yield. In rainfed situations early growth and ripening both occurs under high temperature. Effect of temperature on the early growth of wheat has been studied under controlled conditions (FRIEND et al. 1965 ; FRIEND 1966, ASANA 1974) as well as under field conditions (SISODIA 1977 ; SISODIA et al. 1978). In these studies, information on the nature and magnitude of association of yield components is not available. Presently, there is dearth of suitable genotypes which can make satisfactory early growth if exposed to high temperature by advancing the data of sowing from late October to late September or early October to provide favourable soil moisture status for better germinating stand. Realising the situation, breeding wheat for high temperature tolerance has become increasingly important to get quantum jump in rainfed wheat yield, which requires information on correlation and path analysis to know the nature, extent and direction of selection criteria (DEWEY & LU 1959), This study, therefore was undertaken to determine the components of yield in wheat under high temperature and moisture stress conditions and to suggest suitable parameters for selection under such stress conditions. Materials and Methods The material of this study consisted of 15 diverse genotypes (Table 2). These genotypes were planted on 7. 10. 1982, at Zonal Agricultural Research Station, Powarkheda, M.P., India, in a randomised block design with four replications, having a net plot size of 5 m x 1.20 m (4 ros/30 cm apart) In each variety and in each replication 10 random plants were selected for recording observations on plant height, number of effective tillers per plant, number of spikelets per Spike, ear length, grain weight per ear and grain yield per plant. Genotypes were exposed to 34.5C avearage temperature at the early growth stages by sowing during early October and grown on conserved moisture of the preceding monsoon. No water was applied from sowing to maturity of the crop. Genotypic and Phenotypic correlations were estimated as per MILLER et al. (1958) Path coefficient was calculated by the technique out lined by DEWAY & LU (1959). |
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