2017 ASHS Annual Conference

Irrigation water is one of the most important inputs for any successful potato (Solanum tuberosumL.) production in Colorado. Cost of irrigation water is increasing due to the depleting water table, and the slow rate of aquifer recharge. There is a need to use irrigation water more efficiently in potato production, while sustaining productivity. The recommended quantity of irrigation water applied is equivalent to evapotranspiration (ET) replacement. ET rates can vary among a wide range of potato cultivars. Studies were conducted at Colorado State University San Luis Valley Research Center, to evaluate the impact of reduced irrigation water use below estimated ET on performance of three contrasting Colorado Potato cultivars. Treatments for Canela Russet included 100% ET replacement (full irrigation), 82% ET replacement, and 55% ET replacement. For Mesa Russet, treatments included 100% ET replacement, 90% ET replacement, and 65% ET replacement. Deficit irrigation treatments for Yukon Gold included 61% and 83% ET replacement, and a control with full ET replacement. Reduced irrigation water application was achieved by using the single line source irrigation technique. Full ET replacement increased green leaf area duration in Canela Russet, but the rate of tuber bulking with 18% reduction in irrigation water was similar to that of full ET replacement. Total and marketable tuber yields for Canela Russet were similar for full and 82% ET replacement treatments. Green leaf area duration was longer, and tuber bulking was faster when irrigation water was reduced by 35% in Mesa Russet production. However, total and marketable tuber yields were higher when irrigation water was reduced by 10%. Green leaves persisted longer in Yukon Gold with full ET replacement, but tuber bulking was faster when irrigation water was reduced by 17%. Total and marketable tuber yields were not significantly impacted when irrigation water was reduced by 17%. Data from these studies indicate that potato cultivars can vary in their requirements for irrigation water. Research is therefore needed on cultivar specific water management for new potato cultivars.