Genotype by environment effect on potato (Solanum tuberosum L.) and French fry quality

This thesis investigates the relationships among, stability of, yield, french fry quality and sugar content in potato. Eight potato genotypes were grown in four environments in Ontario, Canada and evaluated for growth yield and quality. Genotype by environment interactions were significant for several traits including french fry colour. For yield and French fry colour AR2000-1 and AR2000-4 were the most stable, respectively. Russet Burbank displayed low levels of stability compared to the other genotypes. The biplot analysis indicated that Elora and Simcoe 2003 ranked cultivars similarly, for yield and French fry. Yield and tuber percent dry matter rankings at final harvest could be determined as early as 90 days after planting while rankings for individual sugars could be determined as early as 60 days after planting. Levels of all sugars in the tuber decreased during storage and the relationship between sugar level and poor French fry colour increased over time.