Identification of Effective Test Sites Represented to Mega-Environment for Sugarcane Breeding Programs in Thailand

Background and Objective: Crop genotypes must go through costly multi-environment experiments (METs), which need suitable test sites to enhance cost effectiveness. This research aims to establish an effective and representative ecological zoning division to enable practical sugarcane cultivar choices. Materials and Methods: The experiment made use of a Randomized Complete Block Design (RCBD) with four replications. The studies were conducted at 22 test sites throughout the nations sugarcane-growing areas. Eight sugarcane genotypes, comprising five genotypes and three commercial checks, were evaluated in this research. Hierarchical clustering or cluster analysis was done to determine the differences between these locations. Results: Based on optimal genotype ranking, Kps 01-12 (G8) and KK3 (G6) were the best performers, having a high mean yield and outstanding stability in the examined environment. Test site grouping was developed with the intention of constructing test sites with negligible GE interactions to choose a representative site from each group for actual testing. Due to location groupings ability to capture the majority of GL interaction, truncation at 12 groups was recommended by the high R-square achieved. Conclusion: By reducing the 22 locations to 12 sites, which would considerably save costs and time, the METs of sugarcane genotypes in Thailand may be improved.