Variety X Environment Interaction in Wheat under Late Sowing

Ten varieties of wheat were evaluated at the five locations in Rajasthan under late sowing conditions for a period of three years. Analysis of grain yield data provided estimates of the variance components.

Under late sowing conditions, a large second order (variety X location X year) interaction was indicated, suggesting that varieties give differential responses when grown in different environments. It was noted that both variety X location and variety X year first order interactions were negative, which evidently shows that there were no consistent location or year effects. Since the first order interactions are relatively small, it apparently makes little difference as to how the present sample of environments is distributed over years and locations. The data suggest that approximately 12 to 14 test environments would be required to obtain a reasonably precise estimate of the varietal performance under late sowing conditions in Rajasthan. Increasing number of replications per trial appear to be less effective than an increase in the number of testing environments.