Effect of meteorological parameters on phenology and yellow rust of wheat

Field experiments were conducted during rabi seasons of 2004-05 and 2005-06 at the Research Farm, Department of Agricultural Meteorology, Punjab Agricultural University, Ludhiana. Wheat variety HD - 2329 was sown on 20(th) November during both rabi seasons with four replications in randomized block design. The phenological stages were recorded visually. Disease spread and intensity was recorded at weekly interval. Disease spread was recorded from inoculated plants in eight radial directions (N, S, E, W, NE, SE, SW and NW). Correlation coefficients between disease incidence and meteorological parameters were worked out. The disease was negatively correlated with maximum temperature and Sunshine hours and was positively correlated with relative humidity during both the years. Multiple regression analysis indicated that the highest r-value was obtained when more number of meteorological parameters were combined. Grain yield was maximum in fourth spread (P4) as it was in SE direction and disease spread was least in this direction.