Abstract:
For analysing the data from field experiments involving qualitative and quantitative
variables, a new approach of using dummy variables for qualitative variables in the
regression equation was tried in with the help of two years data from the experiments
conducted on tomato crop involving four genotypes and four nitrogen levels. The results of
analysis showed that using dummy variables for qualitative variable viz., genotypes in the
regression analysis has the advantage of single equation taking care of differences between
genotypes as well as their individual contribution to yield along with other quantifiable inputs
ake nitrogen. Besides having comparable predicting efficiency of yield with that of individual
functions for each genotype based on ANOVA, dummy variable approach saves a lot of
time and labour especially when a number of genotypes are involved in the experiment, as
otherwise a separate equation has to be fitted for each genotype to catch their effect on
yield.