Colorado Agricultural Experiment Station
Active Projects 2013

Note: A NEW project—initiated within last year—might not have an annual report, publications, or outcomes/impact.
Project: COL00711 Department: San Luis Valley Research Center  
PIs: Essah, SY
Title: Development of cultivar specific management profiles for new and existing potato cultivars.
Begin Date: 07/01/2009 Term Date: 06/30/2014 Most recent project status: O - other
Objectives: Each potato cultivar or advanced selection has its own unique set of cultural management requirements to maximize tuber yield of premium size and grade tubers. Therefore, cultural management guidelines that maximize the production and quality of individual potato cultivars must be developed. The best guidelines for nutrient fertility practices, irrigation management, plant population management, vine kill management for maximum tuber skin set, and other management practices are obtained from field experiments conducted in replicated trials (Essah, 2008). New cultivars are much more successful when release is accompanied by cultivar specific management guidelines. This information relates growth habit and other plant characteristics to nutrient and other plant management strategies for yield and quality goals, which are agronomically sound, economically advantageous, and environmentally responsible. Some cultivar traits such as tuber dormancy can be modified through seed management to the advantage of the grower of a cultivar (Essah et al. 2008). When management guidelines are tailored to individual cultivars, it leads to the successful, sustainable, and economic production of the cultivars, which result in the optimization of their genetic potential, while minimizing economic inputs and environmental impact. In this project, the management profile of each potato cultivar will be summarized in a user friendly language and distributed as fact sheets to the potato industry. These fact sheets can be updated as required. The specific objectives of this project are; 1. Develop optimum nitrogen management guidelines for the production of new and existing potato cultivars. 2. Develop optimum in-row seed spacing for optimum tuber yield, tuber size distribution, and tuber quality of new and existing potato cultivars. 3. Define appropriate vine kill timing for optimum tuber yield, tuber size distribution, and tuber quality of new potato cultivars. 4. Define optimum irrigation water rate for optimum production of new and existing potato cultivars. 5. Evaluate the effect of cut and single drop seed, seed size, and seed reconditioning on tuber performance of new potato cultivars. 6. Evaluate tuber yield, tuber size distribution, and quality of advanced potato selections in grower farms.
Approach: Studies will be conducted to develop optimum N application rate, in-season N application timing, pre-plant N application rate, and pre-plant placement of fertilizers. N application rate will aim at establishing available N (applied, plus soil and irrigation water N) requirements for new and existing potato cultivars. Nitrogen application treatments will include five application rates of 67, 134, 201, and 268 kg N/ha, and a control, where no N will be applied. In-season Nitrogen Application Timing studies will be conducted to evaluate the effect of early, mid, and late application of in-season N on tuber yield, tuber size distribution, quality, and tuber skin set. In-season N application will start after tuber formation. Treatments will include, application of all the in-season N requirement soon after tuber formation, application of half of the in-season N requirement soon after tuber formation, and the remaining half applied 14 days later, application of a third of the required in-season N soon after tuber formation, a third applied 14 days later, and the remaining third applied 28 days after tuber formation. Pre-plant N rate treatments will include 67, 90, and 112 kg N/ha, and a control where no N will be applied pre-plant, but all the N requirements will be applied in-season. Fertilizer Placement and Nutrient Use Efficiency: Treatments will include, band of fertilizer 5 cm below the seed piece, band of fertilizer 5 cm to the side of the seed piece, a band of fertilizer above (broadcast) and to the side of the seed piece. The response of tuber yield, tuber size distribution, and tuber quality to in-row seed spacing will be studied. In-row seed spacing treatment will include 25, 30, 35, and 40 cm. Vine kill timing treatments will include killing potato vines at 90, 100, 110, and 120 days after planting. A study will be conducted to aim at establishing the minimum amount of irrigation water needed for the optimum production of individual potato cultivars. Treatments will include irrigating the potato cultivars as dictated by, the full ET, 80% ET, and 60% ET. Different seed management practices will be developed to modify the genetic traits of individual cultivars that are difficult to grow. Seed management treatments will include, cut seed vrs. single drop seed, seed size and seed reconditioning. On-farm evaluation of advanced potato selections from the Colorado State University potato breeding program will be continued to evaluate yield, yield stability, and tuber quality of the new clones. All data will be subjected to analysis of variance for each variable using SAS (SAS Inst. 1999). Results obtained from this study will be summarized as fact sheets for the potato industry. Workshops will be conducted to make growers aware of the best management guidelines. Results will be presented at potato meetings to growers and consultants. To evaluate the success of this project, surveys will be sent out to determine how many growers are using recommended management practices. Yield and quality of potato tubers will be assessed throughout Colorado by conducting meetings with growers in question and answer sessions.
Keywords: Potato cultivar, nitrogen management, seed spacing, irrigation water management, physiological disorders,vine kill, in-season N management, pre-plant N management, nitrogen rate, available nitrogen, on-farm evaluation, cut seed, whole seed, reconditioning, seed size, fertilizer placement, cultivar management profile.