Genotype x environment interaction of agronomic and processing quality traits in potato

At the main crop production region of Rio Grande do Sul state, Brazil, potato is cultivated in two different growing seasons: autumn and spring. The objectives of this research paper were: i) identify potato clones with high yield potential and industrial quality for Autumn and Spring growing seasons in the northern/northeastern region of the state; ii) estimate the effects of environment and of the genotype x environment interaction on the expression of agronomic and processing quality traits of potato clones in order to determine the appropriate strategy for breeding potato for the target region. One hundred and seventy clones of nine families were developed and compared to the cultivars Atlantic, Baronesa, Catucha, Ciclamen, Hertha, Lady Roseta, Macaca, Monalisa and Vivaldi and to the clone SMIJ 461-1, in the autumn and spring of 2006, in Passo Fundo, northern Rio Grande do Sul state. The evaluated traits included number of tubers per plant, tuber weight, plant yield, presence of deep eyes, dry matter content and chip color. Genotype x environment interaction (G x E) was significant for the expression of all traits but processing quality traits like chip color were most influenced by the growing season conditions. Genetic potential expression for yield traits was maximized in the spring season. Superior clones combining agronomic and quality traits were identified at the two growing seasons. High correlation between the two growing seasons was observed for the presence of deep eyes and dry matter, indicating they can be selected at either season.