Path analysis of the relationships between fruit yield and some yield components in tomato (Solanum lycopersicum L.)

Path analysis was performed on plant and fruit characters of twenty nine tomato genotypes grown in a two years field experiments to determine for fruit yield, the direct and indirect effects of the various yield attributing traits: days to first flowering, days to 50% flowering, number of flower cluster plant-1, primary branches plant-1, secondary branches plant-1, plant height (cm), number of fruits plant-1 and average fruit weight (g). Fruit yield plant-1 was positively and significantly correlated with primary branches plant-1 (0.40, 0.39), number of fruits plant-1 (0.47, 0.37) and average fruit weight (0.59, 0.49) at both genotypic and phenotypic levels, respectively. Path analysis showed that secondary branches plant-1 had the highest positive direct effect (0.89) on fruit yield plant-1 followed by average fruit weight (0.87), number of fruits plant-1 (0.65), days to 50% flowering (0.19) and number of flower cluster plant-1 (0.05), while other traits like days to first flowering, primary branches plant-1 and plant height had negative direct effects. The significant positive correlation coefficients of number of fruits plant-1 and average fruit weight with fruit yield plant-1 were resulted mainly from high and positive direct effects of these traits with fruit yield suggesting direct selection would be rewarding whereas for the characters days to 50% flowering and number of flower cluster plant-1 for which correlation coefficients were negative but the direct effect was positive, a restricted simultaneous selection model is to be followed. For the character like plant height, the indirect causal factors eg. secondary branches plant-1 and number of fruits plant-1 are to be considered simultaneously for selection, since indirect effects seem to be the cause of correlation.