Page 1 Page 2 Page 3 Page 4 Page 5 Page 6 Page 7 Page 8 Page 9 Page 10 Page 11 Page 12 Page 13 Page 14 Page 15 Page 16 Page 17 Page 18 Page 19 Page 20 Page 21 Page 22 Page 23 Page 24 Page 25 Page 26 Page 27 Page 28 Page 29 Page 30 Page 31 Page 32J U L Y / A U G U S T 2 0 1 6 22 POTATO GROWER A primary objective of the North Dakota State University (NDSU) potato breeding program is the breeding, selection, eval- uation, development, and release of chipping potato cultivars possessing cold-sweetening resistance, improved chip processing quality, with high yield potential and multiple resistance to important diseases, insect pests, and environmental stresses. Our efforts pro- vide opportunities to enhance economic and environmental sustainability for potato producers and the chip industry, and the potential for superior quality products for consumers. This report summarizes the NDSU Chip Processing Trial, hosted by Lloyd, Steve and Jamie Oberg, north of Hoople, North Dakota, in 2015. The replicated (4) trial was planted on May 21 using an assist-feed planter. Cultivar specific management practices typical of chip processing production fields in the northern Red River Valley were used; the Hoople trial is non-irrigated (an irrigated chip trial was grown at Hoverson Farms in 2015). Vines were flailed on September 11 and the trial was harvested on October 13 with a single-row Grimme harvester. Days to flailing were 113, while days to harvest were 145. Agronomic characteristics, yield and grade, and chip processing quality traits are summarized in Tables 1-3. Long- term storage evaluation of this material will be processed in mid to late June. Our most advanced chipping genotypes are pictured and described at the end of the article. We hope this summary will serve as a reference for potato producers, research and extension personnel, indus- try representatives, and consumers. Fourteen advancing selections were compared to nine commercially accept- able chip processing cultivars. The selec- tions represent a diverse set of germplasm with several wild Solanum species including S. phureja, chacoense, etubersum, berthaultii, represented in the pedigree of many. In addition to attrib- utes such as cold sweetening resistance, high specific gravity, Colorado potato beetle and insect resistance, resistance to viruses, late blight and water rots, this diverse material may result in selections with a decrease in the tuber size profile, often tuber set is increased, and some tubers may be flat, have deeper eyes or ends (both stolon and apical), and gener- ally be a bit rougher or lower yielding. Percentage stand ranged from 91 to 99; ND7818-1Y and Snowden both averaged 91% (Table 1). Vine sized ranged from small (2.0 for ND113060-1) to large (4.5- 4.8 for Snowden, ND102822CAB- 1ND113307C-3, Lamoka, Pike and Dakota Diamond to name a few). The mean vine maturity was 2.3 (a reflection of the breeding programs effort to iden- tify high yielding early maturing geno- types suited for our short growing sea- sons). The range was 1.0 (very early) for ND7818-1Y to 3.5 for Dakota Diamond. Stems per plant ranged from 1.4 to 2.5 with a mean of 2.0. Tuber numbers per plant averaged 8.0, with a range of 6.1 for ND102858CB-2 to 11.8 for ND8305- 1. Yield and grade for all entries is summa- rized in Table 2. Mean yield was 275 cwt./acre, with a range of 203 cwt./acre for ND113289C-1 to 345 cwt./acre for NDJL21C-1. The mean percentage A- sized tubers (4-10 ounce) was 54, with a range of 17 for ND113060-1 to 70 for Dakota Diamond. Percentage under- sized tubers (0-4 ounces) ranged from 16 for NDJL21C-1 to 83 for ND113060-1, with a mean of 36. NDJL21C-1, Dakota Crisp, Dakota Diamond, Dakota Pearl and Snowden exceeded 15% oversized (>10 oz.) tubers. There were few US No. 2s or culls; tubers were culled or dropped in grade primarily due to growth cracks, misshapen tubers, or greening. At grad- ing, little scab (common) was noted; ND8304-2, ND092018C-3 and Ivory Crisp had a trace. Tuber shape ranged from 1.6 to 2.3 (data not shown), where 1 is round, 3 is oblong, and 5 indicates long tuber shape. Most selections had round tuber shape (1-1.5), however NDJL21C-1 rated a 3.8 so may be more suited for enhancing French fry process- ing genotypes due to the more elongate shape. Skin color (data not presented) ranged from white to flaky (slight net- ting) for Atlantic, Snowden and ND102822CAB-1; ND7818-1Y is yellow. Flesh colors when cut for internal disor- ders were white, creamy and ND7818-1Y has medium yellow flesh. Mean hollow heart/brown center was 0%, thus not reported. Mean specific gravity, an important attribute and indirect measure of tuber dry matter, was 1.0971, with a range of 1.0881 for ND102822CAB-1 to 1.1076 for ND8305-1 (Table 3). Specific gravity in the Northern Plains tends to be quite high across market types. Our focus con- tinues to be identification of chip pro- cessing germplasm that will reliably and consistently process from long-term cold storage. As we grade, chip processing selections are sampled, and stored at 42oF and 38oF (5.5C and 3.3C) for eight weeks (Table 3); a second set is evaluated the following June (materials from this trial will be chipped during the third week of June). In response to industry needs and consumer demands, potato producers and industry personnel are seeking potato cultivars which process 2015 Development of Chip Processing Potato Cultivars with Long-Term Storage Capabilities and Cold Sweetening Resistance In Hoople, North Dakota by Dr. Asunta (Susie) Thompson, NDSU Potato Breeder