ADDITIVE MAIN EFFECT AND MULTIPLICATIVE INTERACTION ON FIXED MODEL OF TWO FACTORS DESIGN

Multilocation trials is usually conducted to study the factors effect of genotype and environment including their interaction in order to increase the yield of crops. The \nenvironment can be considered as giving different doses of fertilizers to each genotype. The present study was aimed to investigate both additive main and interaction effects on fixed model of two factors design. As the application, the \nstudy used a dataset of the yield of paddy in four varieties (IR8, IR5, C4-63, and PETA) given nitrogen fertilizer with six different doses (N0, N1, N2, N3, N4, and N5). The first step of analysis was estimating variance component using fixed model ANOVA (Analysis of Variance). Then, AMMI (Additive Main Effects and Multiplicative Interaction) model was applied which is the combination of additive \nmain effect and the principal component analysis (PCA) of interaction effect. The result of study shows that the variance component has positive value for all factors \nof treatment. AMMI analysis produces AMMI-2 as the best model at the significant level of α = 0.05. The biplot of AMMI-2 obtained that IR5 can adapt to nitrogen fertilizer in any level. Spesific interaction occurs in variety C4-63 in nitrogen level, variety IR8 in nitrogen level, and variety PETA in nitrogen level. Based on the result of study, it can be concluded that the use of AMMI fixed model in two factors design can effectively explain the effect and the pattern of interaction structure among treatment factor level