Yield Stability of Three Newly Released Tomato Varieties (Lycopersicon Lycopersicum) and Two Commercial Checks Evaluated in Ten Environments across Three Agro-Ecological Zones of Nigeria

Abstract

Three newly released tomato varieties, HORTITOM1, HORTITOM2 and HORTITOM3 and two commercial checks (Onityre and farmers’ variety) were evaluated in 10 environments covering the Rainforest, Guinea and Sudan savannah to determine their stability across the test environments. The five (5) tomato varieties were evaluated using a Randomized Complete Block Design (RCBD) with two replications. The experimental unit used in all the locations was 11.5m x 11m with the spacing of 0.6m within rows and 0.5m between plants. Additive Main effect and Multiplicative Interaction (AMMI) and Genotype x Environment Interaction (GGE) biplot were used to estimate the yield stability among the five varieties of tomato across the 10 environments. Data on agronomic and yield characters collected include: plant height (cm), stem girth (mm), days to first flowering, number of branches per plant, fruit weight per plant (g) and unit fruit weight (g). The data collected were subjected to combine analysis of variance while AMMI analysis was done using the formula proposed by Purchase (1997). The results revealed significant variations for genotypes, environments and genotypes x environment interaction which indicated that the genotypes performed differently across the test environments. HORTITOM3 (G3) was the best overall in fruit yield and this was followed closely by HORTITOM1 (G1) and HORTITOM2 (G2). The three improved varieties out-performed and were significantly different from the two local checks with relation to yield. G3 was the highest yielder while G4 (Onityre) and G5 (Farmer’s variety) were lower yielders. G1 and G3 were considered as unstable genotypes while G2 was the most stable genotype across the test environments. In conclusion, G2 (HORTITOM2) was identified as most stable variety and is recommended for stability across the three agro-ecological zones in Nigeria used for the study while G3 (HORTITOM3) with the highest yield is recommended for cultivation in Rainforest agro-ecological zone.