Case Study of Postharvest Quality of Clearwater Russet Potato Cultivar from Commercial Production in the Columbia Basin

Abstract Potato quality traits, particularly carbohydrate composition, are shaped by genotype, management, and environment. Clearwater Russet was bred for high U.S. No. 1 yield and resistance to cold sweetening, although anecdotal reports indicate postharvest fry color varies across environments and practices. To assess this variability, five commercial fields in Washington’s Columbia Basin, spanning up to 240 km and representing different growers, were sampled in 2023. Evaluations included specific gravity, reducing sugars, and fried sample reflectance across multiple developmental and storage stages. Fry color loss, color uniformity, and temporal responses differed significantly among fields. These results show that, despite its breeding objectives, Clearwater Russet can display variable postharvest and processing performance under commercial conditions. The findings highlight the importance of integrating commercial-scale data into variety evaluation, providing insights to improve research, refine grower recommendations, and support successful cultivar adoption.