This study evaluates the separate effects of site, variety, and fertilizer application on three key rice performance indicators plant height, tiller height, and grain yield using univariate analysis of variance (ANOVA). A field experiment was conducted across three sites in National Cereals Research Institute Baddegi Niger state, Nigeria, using four rice varieties and three fertilizer treatments. Data were analyzed using Type III ANOVA to isolate the main effects and interactions on each dependent variable. The results for plant heights, significant main effect were observed for site and variety, indicating that both environmental factors and genetic difference among rice varieties influence plant height. Additionally the interaction between site and variety was significant suggesting that the performance of rice varieties in terms of plant height was site dependent. However, fertilizer has no significant effect and no interactions between fertilizer and the other factors significantly influence plant height. Regarding tiller height, significant main effect were found for site and fertilizer, indicating that all three factors independently contribute to variations in the tiller height. The findings suggest that site and genetic factors predominantly influence vegetative growth, whereas yield outcomes may depend on more complex or longer-term factors. This study emphasizes the utility of univariate models for targeted agronomic trait analysis and field-level decision-making.
Alfa et al. (Mon,) studied this question.