NC STATE University

North Carolina

Potato Variety Trial and Breeding Report

2002

G. C. Yencho and M. E. Clough
Department of Horticultural Science
North Carolina State University
Vernon G. James Research and Extension Center
207 Research Station Road
Plymouth, NC 27962
Tel: 252-793-4428 ext. 147
Fax 252-793-5142
Email: Craig_Yencho@ncsu.edu
Web Address: http://www.ces.ncsu.edu/plymouth/hort/potato/

I. OBJECTIVES:

Our research is conducted in collaboration with the USDA Cooperative States Research Extension and Education Service (CSREES) NE-184 Multi-state Potato Variety Development and Evaluation Project. The overall objective of the NE-184 Project is to develop high yielding, disease and insect resistant, table- and chip-stock potato varieties for potato growers in the eastern US. The objective of the NC State University variety development and breeding program is to evaluate germplasm, and select and develop better adapted potato varieties that are suitable for use by the North Carolina growers, and the southeastern US potato industry in general.

II. PROJECT SUMMARY

Our program focuses on two areas: the development of new potato germplasm and varieties through collaborative early-generation breeding and selection projects with the USDA-ARS, Cornell University and the University of Maine; and the evaluation of preliminary and advanced breeding clones for adaptation to NC from a wide range of potato breeding programs in the US and Canada. In 2002, we planted 7411 single-hill plots, 828 four hill plots, 183 six hill plots, 12 12-hill plots and 28 20-hill plots for the breeding program. While, a total of 164 preliminary and advanced clones were evaluated in replicated yield trials either on-farm, or at the Tidewater Research Station (NCDA&CS)/Vernon G. James Research and Extension Center, (NCSU) in Plymouth, NC. The results of the yield trials are summarized later this report, and in Tables 1-10.Each table has two parts, the first (a) being devoted to yield information, specific gravity measurements, and chip color scores, and the second (b) providing potato plant and tuber quality characteristics. This report can also be viewed and downloaded at our website http://www.ces.ncsu.edu/plymouth/hort/potato/index.html.

In 2002, the USDA clones with the most potential as chippers were: B0564-8, B0766-3, and B1240-1. In all cases, yields were good and chip scores were 2 or 3.The clone B0564-8 is scheduled for release by the USDA-ARS in 2003 as the variety Harley Blackwell.It is an attractive, round-white potato with a medium net skin and an average specific gravity in NC of 1.073 compared to 1.076 for Atlantic. B0564-8 is primarily intended for chipping, but its attractive appearance and lower gravity compared to Atlantic may also make it suitable for table-stock purposes.In NC, it has produced marketable yields 108% of Atlantic, but it does not suffer from internal heat necrosis (IHN), a common problem of Atlantic in the mid-Atlantic regions.

The table-stock clones from the USDA with the most potential were: B1752-5 a round, yellow-fleshed potato; B1758-4 a red-skinned, white-fleshed clone; and B1816-5 a purple-skinned, yellow-fleshed clone. All three had minimal incidence of internal defects. The reds need further testing. We believe B1816-5 has good potential as a specialty-type potato, and we will be testing it with the NCSU Specialty Crops Program and on-farm in 2003.

Clones from the University of Maine showing the most promise were: AF1424-7 and AF1569-2. In most trials the marketable yields for these were good, there were few internal defects, and chip scores for were either 2 or 3.

From Cornell University NY112, NY126, and NY129 performed well. NY112 is an especially attractive, netted, chip-stock potato with good yields, however, it has suffered from susceptibility to IHN making it unsuitable for North Carolina. NY126 and NY129 have promise as table-stock varieties and we will continue intensive evaluations of these clones.NY126 is an attractive, round to oblong, pale yellow-fleshed potato with yields close to Atlantic. NY129 is a round, red-skinned, white-fleshed potato with few internal defects and yields close to Chieftain.

Nordonna is an attractive round, red-skinned, white-fleshed potato from North Dakota that has performed well in many of our yield trials with an average marketable yield of 207 cwt/A.However, we have seen a fair amount of secondary growth in this clone over the last two years and thismay limit its overall acceptance in NC.

Two clones from Michigan that yielded and chipped well were: MSH031-5 and MSH095-4, each having comparable gravity and yield to Atlantic and low incidence of any internaldefects.

Vivaldi, a medium to large yellow-fleshed oblong table-stock potato from HZPC, was very attractive, and had low incidence of internal defects and yields comparable to Atlantic. This clone is very attractive in NC and will be tested further.

III. RESEARCH STATION AND ON-FARM COOPERATOR LOCATIONS:

Tidewater Research Station (NCDA&CS)/Vernon G. James Research and Extension Center, (NCSU), Plymouth, NC (Washington Co.)

Cooper Farms, Gumneck, NC (Tyrrell Co.)

James Brothers Farms, Weeksville, NC (Pasquotank Co.)

McCotter Farms, Vandemere, NC (Pamlico Co.)

Tull Hill Farms, Kinston, NC (Lenoir Co.)

COOPERATING COUNTY EXTENSION SPECIALISTS:

Tom Campbell, Elizabeth City, Pasquotank Co.

Bill Jester, Kinston, Greene, Lenoir, and Wayne Co's.

Fred May, Bayboro, Pamlico Co.

Richard Rhodes, Columbia, Tyrrell Co.

IV. PROCEDURES:

SITE, SOIL TYPE, PLANTING AND HARVEST DATES

EXPERIMENTAL DESIGN: All yield trials were planted in a randomized complete block design with 4 replications except the preliminary evaluation trial, which had only one replication per clone. Sixteen clones were evaluated at Cooper's and McCotter's, while 12 and 22 clones, respectively, were evaluated at the Tull Hill and James Brother's on-farm trials.Plots consisted of one row with 28 hills spaced 9 inches apart. Spacing between rows was 38 inches at all sites, with the exception of the James Brother's Trial, which was on a 40 inch row spacing.Weed and pest control practices for on-farm trials were in accordance with those practiced by the cooperators (Appendix 1).

The on-farm trials were dug using a single-row digger and hand harvested.The research station trials were harvested using a two-row harvester modified to dig one row at a time.All grower trials were graded using a portable Lockwood Grader which sorts to two grades: A+B's ³ 1 7/8"; and C's < 1 7/8".The TRS/VGJREC trials were graded to five classes: 1's < 1 7/8"; 2's > 1 7/8 to 2 1/2"; 3's > 2 1/2 to 3 1/4"; 4's > 3 1/4 to 4"; 5's > 4". Culls were removed and weighed separately in all trials.Each clone was evaluated for tuber quality and appearance during grading using standardized NE-184 rating codes. A description of the rating codes is provided in Appendix 2.

After grading and weighing, 40 marketable tubers (10 tubers/replication) were randomly sampled from each entry. The tubers were cut and scored for the presence of hollow heart, heat necrosis and any other internal defects. A second sub-sample of marketable tubers from each replication was taken and bulked by entry for specific gravity readings and chipping tests.Specific gravity was determined using the weight-in-air/weight-in-water method.Chip evaluations were conducted at the TRS/VGJREC and Wise Foods, Berwick, PA.

Chip evaluations were conducted by Wise Foods and at the TRS/VGJREC for all on farm trials, and at the TRS/VGJREC for all research station trials.Chipping at the TRS/VGJREC was done at least once within 48 hrs of harvest. To transport the potatoes for chip samples at Wise Foods in Berwick, PA the potatoes (5 tubers per sample) were placed in a plastic mesh bag and loaded on the back of a truck en-route to Wise.In most cases, chip evaluations were conducted within 72-96 hrs of digging.

V. RESULTS:

Environmental Summary (Appendix 3)

Eastern NC's potato season was highly variable this year.Our season started wet putting us behind at planting, especially on the research station. Thereafter, temperatures fluctuated between hot and cool, while remaining extremely dry at most sites, until the very last week of the season when several heavy rains occurred resulting in much lower yields than normal. Yields at the research station were considerably lower compared to previous years due to thelate planting and subsequent drought.

The hot dry weather during the first 1.5 months of the season is thought to have contributed to an outbreak of Tomato Spotted Wilt Virus (TSWV).To the best of our knowledge this it is the first time that TSWV has occurred so widely on potatoes in NC.The virus has a very wide host range including weedy and cultivated species and is vectored by thrips.Table 11 summarizes % TSWV incidence recorded per clone in our replicated yield trials while Table 12 summarizes mean % TSWV incidence by variety trial. Table (b) for each trial also provides data on % incidence of TSWV by clone.Clearly, Atlantic is on of the more susceptible varieties.

A. Yield Trials

1. On-Farm Trials

Cooper Variety Trial (Tables 1a and 1b)

Atlantic, our standard, had a marketable yield of 201 cwt/A and though no other clone had a significantly greater marketable yield, NY112 bested the standard at 247 cwt/A.Eight clones had a chip score rating of 2 at both the TRS and Wise. These were: AF1938-3; Atlantic; B0564-9; B0564-8; B0766-3; MSH031-5; MSH095-4; and Snowden.Two clones, B0564-8 and B0564-9, received overall appearance scores of 8. Others that scored high were: AF1938-3; Atlantic; B1752-5; and NY112.All clones with IHN had a rating of 8, which is not severe. Atlantic had 10% incidence of IHN and B1752-5 had 7%.Brown center was observed in several clones.The two with the highest incidence were: Suncrisp (32%) and Superior (17%). The primary defects in the trial were misshapes, and sunscalds.

James Brother's Variety Trial (Tables 2a and 2b)

Atlantic had a marketable yield of 236 cwt/A. Snowden had a significantly greater marketable yield of 325 cwt/A.None of the clones chipped better than good (<3). In terms of appearance the only clone to receive an 8 was NY127.Others with a 7 were: AF1569-2; B1758-4; NY126; Vivaldi; and Yukon Gold. Four Clones having an IHN incidence greater than 10% were: AF1470-6 (12%); AF1565-12 (17%); AF1569-2 (22%); and Atlantic (17%). But, none had an average IHN rating greater than 8. Hollow heart was observed in AF1569-12 at 10%, while vascular ring defects were observed in AF1569-12 (15%), B1240-1 (15%), Fabula (20%), and MSH095-4 (22%). Culls were primarily due to chain tubers, secondary growth and sunscald.

McCotter Variety Trial (Tables 3a and 3b)

This trial was severely impacted by TSWV and the site was very dry most of the season.The marketable yield of Atlantic in this trial was 195 cwt/A. Snowden had the highest marketable yield at 232 cwt/A.Gravities in this trial were generally higher than most of our other trials due to the drought.Atlantic had a gravity of 1.082, NY125 had a gravity of 1.083 and Yukon Gold had the highest gravity at 1.084.Only one clone, B0564-8, chipped better than a 3 at both the TRS and Wise. B0766-3 was rated the most attractive with an appearance score of 7.Overall, IHN incidence was low and no clones were rated less than 8. Defects were primarily misshapes, secondary growth and sunscald.

Tull Hill Farms Red Variety Trial (Tables 4a and 4b)

Chieftain, our red standard, had a marketable yield of 246 cwt/A.None of the other clones inthe trial exceeded the standard. There were however, three clones with statistically similar yields: B1816-5 (230 cwt/A); Cherry Red (200 cwt/A); and NY129 (228 cwt/A). Clones with overall appearance scores of 7 or greater were: B1816-5, a purple-skinned, yellow-fleshed clone, and NY129.Clones with percent IHN levels greater than 10% were: Chieftain (35%); Ida Rose (15%); and Symfonia (22%). Clones with 10% incidence of brown center or greater were: B1758-3 (10%); B1758-4 (12%); ND3196-1R (27%); and Symfonia (22%).The most common defects were soft rot, misshapes and silver scurf.

2. Research Station Yield Trials

Round White Trial 1. (Tables 5a and 5b)

Of the twenty-two clones in this trial, ten had marketable yields greater than Atlantic, which yielded only 145 cwt/A.However, only two clones: B0564-9 (179 cwt/A) and Snowden (219 cwt/A) had significantly higher marketable yields.The clones with the highest gravities in this trial were: AF1424-7 (1.081) and AF2217-3 (1.083).In terms of chipping, ten clones had scores of 2 and one clone, Snowden, had a score of 1. Four clones, B0564-8, B0766-3, NY126, and Yukon Gold, received an overall appearance rating score of 7. Clones with 10% or more incidence of IHN were: AF2215-3 (15%); Atlantic (40%); and Yukon Gold (10%). The most severe IHN rating was a 7 for Atlantic.Atlantic also had 17% brown center.Soft rot was noted internally in all but three clones and seven clones had incidence of 10% or more.These were: AF1565-12 (12%); AF1569-2 (27%); AF1763-2 (10%); B0564-8 (12%); B0766-3 (10%); B1752-5 (12%); and Fabula (10%).Common defects were misshapes, soft rot, sunscald, and Rhizoctonia.

Round White Trial 2. (Tables 6a and 6b)

Atlantic had a marketable yield of 116 cwt/A in this trial.Five clones, AF222-3 (168 cwt/A), AF2269-8 (168 cwt/A), B2024-10 (153 cwt/A), NY112 (180 cwt/A), and Snowden (202 cwt/A), had significantly higher yields. Five clones (AF2207-4, AF2222-2, AF2269-8, B2001-197, and NY125) had a chip rating of 2.Four clones (AF2269-8, B2024-10, NY112, and NYU47-21) were rated as a 7 for overall appearance.Two clones, Atlantic (27%) and B2024-10 (12.5%), had greater than 10% IHN incidence.The heat necrosis severity ratings for these two clones were 6 and 5 respectively while all other IHN ratings were 8 or 9.Two clones with a 10% or greater incidence of brown center were: Atlantic (10%) and NYU47-21 (17%).Culls were mostly for misshapes, sunscald, and soft rot.

NE-184 White Trial. (Tables 7a and 7b)

Of the twenty-four clones in this trial none had marketable yields greater than Atlantic. However, five equaled that of Atlantic (ATX84706-2Ru (170 cwt/), B1240-1 (176 cwt/A), Kennebec (177 cwt/A), Superior (174 cwt/A), and W1313 (170 cwt/A).One clone, Snowden, received a chip rating of 1 and eight other clones had a rating of 2 (AF1455-20, AF1470-6, ARS-W96-40006-1, ARS-W96-4654-1, B1240-1, B1425-9, W1242, and W1313).Two clones (AF1470-6 and Yukon Gold) were rated a 7 for overall appearance. Three clones had 10% or greater incidence of IHN.These were: ARS-W96-4654-1 (40% at a rating of 7); Katahdin (10% at a rating of 8); and Russet Burbank (73% at a rating of 6).Two clones Gem Russet (20%) and Superior (15%) had 10% or greater incidence of brown center.Ten percent or greater incidence of soft rot was noted in AF1569-2 and ARS-W96-40022-5.Culls were commonly misshapes, sunscald, soft rot, and Rhizoctonia.

NE-184 Red Trial. (Tables 8a and 8b)

The standard, Chieftain, had a marketable yield of 229 cwt/A.Only one clone, Roselys, had a higher marketable yield than Chieftain but it was not statistically different and it was not particularly attractive. NorDonna and NY129 had on overall appearance ratings of 7.Five clones (B1758-3, Brise du Nord, Chieftain, Ida Rose, and Symfonia had greater than 10% incidence of IHN.Culls were due mostly to misshapes, growth cracks, and Rhizoctonia.

Unreplicated Trial (Tables 9a and 9b)

Fifty-four clones were evaluated in this trial along with the standards Atlantic, Snowden and Superior. Each 28-hill plot was unreplicated. Clones with promising attributes such as high yield, high specific gravity, exceptional appearance and/or highdisease resistance will be evaluated in following years in replicated trials.

B. Breeding and Early Generation Selection Efforts

1. NCSU/USDA-ARS Early Generation Project. (10a and 10b)

This project, conducted in cooperation with Dr. Kathleen Haynes, USDA-ARS, is an on-going effort focused on developing improved varieties more suitable to the range of climates and photoperiods found in the Mid-Atlantic and Southeastern U.S.In 2002, 15 clones remaining from three years of selection for yield and appearance in Maine and North Carolina during the last three years were evaluated for the first time in replicated trials in Virginia and North Carolina.The results obtained in these trials are preliminary and all of the clones are scheduled for reevaluation in 2003

USDA EG 6-Hills

In 2002, 187 6-hill plots were planted with 17 being selected in NC, and 20 selected in ME.Three selections overlapped in both sites for a total of 34 selections.Of the 17 selections made in North Carolina, 11 were selected in NC during the 2001 single-hill harvest, and one of those was selected in both ME and NC. Of the 20 selected in Maine, 13 were selected in ME the previous year with only one being selected in both sites during the 2001 growing season.

USDA EG 20-Hills

Our third year selections were made on 20-hill plots. After this stage, the clones are placed in multi-state yield trials as described above. This year, 27 clones were planted and we selected eight in NC, and three in ME.During this cycle of selection there was no overlap so a total of eleven clones remain.Of the eight selected in NC only four were selected in NC in 2001 and of those only one was selected in NC during the 2000 single-Hill harvest. Of those selected in Maine one was selected in ME last year and it was also selected in Maine from the 2000 single hills.

2. NCSU/Univ. of Maine Early Generation Project

UM EG 4-Hills

Our collaboration with the University of Maine (UM) is similar to the USDA-ARS Early Generation project in that it is a in an attempt to develop more adapted clones for the mid-Atlantic and Southeastern regions of the US.It differs in that the UM sends us a single large tuber of each of their first-year, single-hill selections that we cut into four pieces and plant as four-hill. UM retains then retains all of the selections that we make assuming that the are not too ugly. For 2002, we planted 287 four-hill plots and selected twenty-four.These selections will be reviewed next year in 12 hill plots.

UM EG 12-Hills and 20-Hills

Two out of twelve 12-Hill plots were selected , and no 20-hill plots were advanced this year.

3. NCSU/Cornell Univ. Early Generation Project

Cornell EG 4 Hills

This project follows the same format as the UM EG project.This year we screened 541 clones in 4 Hill plots and selected 68.These will be evaluated in 2003 as 12-hill plots.

V. ACKNOWLEDGMENTS

This work could not be conducted without the assistance of the growers, county extension agents and NCDA&CS TRS staff. We are grateful for their continued support and assistance. Wise Foods, Berwick, PA is also gratefully acknowledged for conducting chip tests.HZPC Americas Corp provided an unrestricted gift for variety evaluation, which benefited the project.Seed for the trials were provided by: Dr. Dave Douches, Michigan State University; Dr. Kathleen Haynes, USDA/ARS, Beltsville, MD; Dr. Susie Thompson, North Dakota State University; Dr. Walter De Jong Cornell University; Dr. Greg Porter, University of Maine; Ms. Nena Huston and Mr. Garland Grounds, University of Maine; and from HZPC Americas Corp. Also a special thanks goes to Agway Seed Potato Department for their efforts to procure small amounts of seed for shipment to NC. This project is funded in part by The North Carolina Potato Growers Association and the USDA CSREES. Their continuing support is much appreciated.