Potato (Solanum tuberosum) production generally requires added nitrogen (N), which is costly and potentially environmentally damaging. One path to limiting N application is breeding N efficient potatoes. Effective use of nitrogen, across crops, is typically characterized in terms of yield. However, tuber quality characteristics affect potato marketability, especially for red fresh market potatoes. While optimal N rates maximize yield, the genotype-specific effect of N on tuber quality traits is unclear. In order to highlight quality traits effected by N, identify germplasm with lower N requirements, and determine optimal N rates for red-skinned clones, we conducted a variable N rate experiment over two years in Minnesota. Eight red fresh market genotypes were grown in RCB factorial design with five nitrogen application rates ranging from 0 to 81.6 kg/ha. Best linear unbiased estimates were calculated for yield, skin color, skin set, and tuber shape. The models for yield and quality traits included significant genotype by N rate interaction effects, suggesting that there is variation in the way clones respond to N. Established varieties were more responsive to added N than breeding lines. Similarly, established varieties tended to produce more oblong tubers under higher N conditions, while the breeding lines remained round. Color traits also responded to N in a genotype-specific way, while the interaction effect for other traits depended on unmeasured environmental factors. No clone exhibited increased yield above the 54.4 kg/ha rate. Our results suggest that the 81.6 kg/ha rate produced less favorable phenotypes for all traits.
Bibliographical noteFunding Information:
Funding: This project was funded by the USDA National Institute of Food and Agriculture award number 2016-34141-25707.
This project was funded by the USDA National Institute of Food and Agriculture award number 2016-34141-25707.Acknowledgments: We are grateful for the support of Minnesota?s potato growers. In particular, Sandi Aarestad at Valley Tissue Culture at Halstad MN provided us with the seed for the commercial varieties in this experiment. Additionally, Peter and Paul Imle of Pine Lake Wild Rice at Gonvik MN, provided the seed for the three Minnesota breeding lines which they had been preserving on their farm during times of uncertainty in the breeding program. At the University of Minnesota, we appreciate Ron Faber?s dedicated and exemplary management of our field sites. We would also like to thank the many people involved in maintaining and phenotyping the plants in the experiment: Husain Agha, Katelyn Filbrandt, Jessica Huege, Colin Jones, Thomas McGehee, Laura Schulz, and Heather Tuttle. Finally, we appreciate Paul McGuirk?s editing and formatting efforts and the recommendations of two anonymous reviewers.
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- Skin quality
- Tuber shape