Response of Two Colorado Russet Potato Cultivars to Reduced Irrigation Water Use

Abstract

In most irrigated potato (Solanum tuberosum L.) production systems, the amount of irrigation water applied is equivalent to or greater than evapotranspiration (ET) replacement. ET is mostly estimated for a wide range of potato cultivars, which often leads to over or under irrigation of some cultivars. Studies were conducted at Colorado State University’s San Luis Valley Research Center to evaluate the effect of limited irrigation water below the estimated ET on performance of two new Colorado Russet potato cultivars ‘Mercury Russet’ and ‘Rio Grande Russet’. For Mercury Russet, treatments included 80%, 90%, and 100% ET replacement in 2014, and 70%, 82%, and 100% ET replacement in 2015. Treatments for Rio Grande Russet included 80%, 90%, and 100% ET replacement in 2014, and 79%, 85%, and 100% ET replacement in 2015. A reduction of irrigation water by 20% in 2014 and 30% in 2015 delayed leaf senescence of Mercury Russet until 86 to 90 days after planting (DAP). Tuber yields obtained under 10% and 18% reduced irrigation water equaled yields obtained under 100% ET treatment. For Rio Grande Russet, LAI was not impacted with limited irrigation water in 2014, but in 2015 LAI reduced with 15% or more irrigation water reduction. Limiting irrigation water beyond 20% reduced tuber yields in Rio Grande Russet. Data from these studies indicate that irrigation water applied in the production of Mercury Russet and Rio Grande Russet can be reduced up to 18% and 15%, respectively, without affecting tuber yield and quality.