NC STATE University

North Carolina

Potato Variety Trial and Breeding Report

2003

Web Address: http://www.ces.ncsu.edu/plymouth/hort/potato/index.html

I. OBJECTIVES:

Our research is conducted in collaboration with the USDA Cooperative States Research Extension and Education Service (CSREES) NE1014 Multi-state Potato Variety Development and Evaluation Project. The overall objective of the NE1014 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 adapted potato varieties that are suitable for use by 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 2003, we planted 8,364 single-hill plots derived from true potato seed obtained from USDA-ARS and NCSU crosses and made 236 selections. We also planted 202 four-hill plots from the University of Maine and the USDA, 167 six-hill plots from last years single-hill selections in NC, 48 12-hill plots from the University of Maine and Cornell University, and 63 20-hill plots from the USDA and the University of Maine were also planted. In addition, a total of 197 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 in this report, and in Tables 1-9. 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 2003, the USDA clones with the most potential as chippers were: Harley Blackwell, and B0766-3. In all cases, yields were good and chip scores were 3 or better. The clone Harley Blackwell, formerly known as B0564-8, was released by the USDA-ARS this year. 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. Harley Blackwell is primarily intended for chipping, but its shallow eyes, relatively 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. It does not suffer from internal heat necrosis (IHN), a common problem of Atlantic in the mid-Atlantic and SE US.

The table-stock clones from the USDA with the most potential were: B1806-8 a round, yellow-fleshed potato; B1758-4 a red-skinned, white-fleshed clone; and B1816-5 a purple-skinned, yellow-fleshed clone. In terms of internal defects B1806-8 and B1758-4 have expressed hollow heart, brown center and some soft rot but overall incidence has been less than 10%. However, it must be noted that these defects did show up this year in higher percentages. B1816-5 has been consistently free of major defects, and we believe that this clone has good potential as a specialty-type potato. We will continue testing it with the NCSU Specialty Crops Program and on-farm in 2004.

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 (recently released as Marcy), NY126, and NY129 performed well. Marcy (NY112) is an especially attractive, netted, chip-stock potato with good yield. However, it has suffered from susceptibility to IHN making it potentially unsuitable for NC. 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 similar to Chieftain.

Two clones from Michigan of note are: MSI005-20Y and Michigan Purple. MSI005-20Y is an attractive light yellow flesh, white skin potato with few internal defects though its yields were off. Michigan Purple is a high yielding purple skin, white flesh potato. We consistently rate this clone with a low appearance score but this is largely due to excessive skinning and its high susceptibility to scab. Growers (organic and conventional) who take special precautions to minimize skinning and do not have scab problems, and/or home gardeners who hand harvest potatoes might be the appropriate market for this unique potato in NC as it is flavorful, and itÕs smooth light purple skin and white flesh are very attractive.

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.)

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

COOPERATING COUNTY EXTENSION SPECIALISTS¹ AND EXTENSION ASSOCIATES²:

Tom Campbell¹, Elizabeth City, Pasquotank Co.

Bill Jester², Kinston, Greene, Lenoir, and Wayne CoÕs.

Richard Rhodes¹, 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 CooperÕs, while 13 and 24 clones, respectively, were evaluated at the Tull Hill and James BrotherÕs 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 BrotherÕs 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-1014 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 to Wise Foods in Berwick, PA for chip samples 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)

Our season started wet in most sites and our typically cool temperatures put us about a week behind at planting. The cold moist soils resulted in poor stands in several locations. Throughout the growing season and into harvest the season remained wet with mean temperatures remaining very close to the historical 30-year averages. Despite these conditions over all trials soft rot was not a major problem. Among other observations, we have noticed over the last two years that fire ants are tunneling into some of our potatoes. With their slow progression North, this may become a pest of concern in the future.

A. Yield Trials

1. On-Farm Trials

Cooper Variety Trial (Tables 1a and 1b)

Atlantic, our standard, had a marketable yield of 296 cwt/A and three clones had significantly greater marketable yields: B2135-163 (347 cwt/A); Marcy (357 cwt/A); and NY126 (381 cwt/A). Three clones (B0766-3, NY126 and Snowden) had a chip score rating of 2 or better at both the TRS and Wise. One clone, Harley Blackwell (B0564-8) received an overall appearance score of 8. B1829-5 and Marcy also had good appearance scores. All clones had an IHN rating of 8 or better, which is not severe. Atlantic had 10% incidence of IHN and B1970-1 had 8%. All but four clones (B2029-1, MSH095-4, Snowden, and Superior) had some incidence of hollow heart. Those with greater than 10 percent were: Atlantic (28%); B1240-1 (23%); B0766-3 (18%); B2135-163 (13%); and MSF373-8 (13%). The primary external defects observed in the trial were misshapes, soft rot, and sunscald.

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

James BrotherÕs Variety Trial (Tables 2a and 2b) Atlantic had a marketable yield of 217 cwt/A. Two clones, Harley Blackwell (248 cwt/A) and Marcy (258 cwt/A), had significantly greater marketable yields than Atlantic. Three clones chipped with a score of 2 at both the TRS and Wise: Atlantic; Harley Blackwell; and B0766-3. In terms of overall appearance three clones received an 8: Harley Blackwell; Marcy; and NY129. Clones with an overall appearance score of 7 were: B2163-163; NorDonna; and Superior. Only one clone, Superior (20%), had an IHN incidence greater than 10% and none had an average IHN rating greater than 8. Culls were primarily due to misshapes, sunscald, and growth cracks.

Tull Hill Farms Red Variety Trial (Tables 3a and 3b)

Chieftain, our red standard, had a marketable yield of 339 cwt/A. None of the other clones in the trial exceeded the standard though many had statistically similar yields. The only clone with an overall appearance score of 8 was NY129, a round red from Cornell University. Clones with overall appearance scores of 7 were: B1758-4; B1952-2; and NorDonna. NorDonna, while being attractive, still has severe problems with secondary growth as is evidenced by the fact that roughly 25% of its total yield was culled for this condition. The only clone with percent IHN levels greater than 10% was Chieftain (25%), but the IHN severity rating was not exceptionally serious at 7.8. Clones with 10% incidence of brown center or greater were: B1758-4 (23%); Cherry Red (18%); and La Rouge (13%). The most common external defects were soft rot, misshapes, skin blemishes attributed to Rhizoctonia, and silver scurf.

2. Research Station Yield Trials

Round White Trial. (Tables 4a and 4b)

Of the twenty-eight clones in this trial, four had marketable yields greater than Atlantic, which yielded 181 cwt/A. None of the four (AF1424-7(195 cwt/A); B1808-6 (190 cwt/A); Marcy(194 cwt/A); and Yukon Gold (187 cwt/A)) were, however, significantly greater. Several clones in this trial had high gravities for NC. The highest was Atlantic (1.091), others were: AF2363-11 (1.088); AF2291-10 (1.087); and AF2242-10 (1.083). In terms of chipping, six clones (AF1455-20, AF2351-2, Atlantic, B0766-3, B2135-163, and Marcy) had a score of 1. Six clones (Harley Blackwell, B0766-3, B1806-8, MSI005-20Y, Marcy, and Yukon Gold) received an overall appearance rating score of 7 and one clone B2163-163 received a score of 8. Clones with 10% or more incidence of IHN were: AF2326-1 (15%); Atlantic (20%); and MSJ461-1 (25%). AF2326-1had the most severe average IHN severity rating was at 7.3. Three clones (Atlantic (28%), B2135-163 (18%), and Marcy (10%)) had 10% or greater incidence of hollow heart. Incidence of soft rot (10% or greater) was noted in six clones: AF2206-9 (10%); AF2242-10 (33%); Atlantic (10%); Harley Blackwell (10%); B0766-3 (13%); and B1806-8 (10%). Common defects were misshapes, soft rot, sunscald, growth cracks, and skin blemishes attributed to Rhizoctonia.

NE-1014 White Trial. (Tables 5a and 5b)

Of the twenty-four clones in this trial none had marketable yields significantly greater than Atlantic (200 cwt/A). However, NY125 (208 cwt/A) and Snowden (216 cwt/A) equaled Atlantic. Six clones received a chip rating of 1 (exceptionally bright): AF1938-3; AF2207-4; AF2222-2; Atlantic; B1806-8; and NY126. One clone, NY125 was rated an 8 for overall appearance and five clones (AF2222-2, B1240-1, Ivory Crisp, Katahdin, and NY126) were rated a 7. Only AF2115-1 had 10% incidence of IHN. Clones with 10% or greater incidence of hollow heart were: AF1753-16 (13%); AF2222-2 (18%); Atlantic (10%); ATX84706-2Ru (10%); and B1806-8 (20%). Ten percent or greater incidence of soft rot was noted in AF1455-20 (10%) and AF2215-1 (18%). Culls were commonly misshapes, sunscald, growth cracks, and skin blemishes attributed to Rhizoctonia.

NE-1014 Red Trial. (Tables 6a and 6b)

The standard, Chieftain, had a marketable yield of 168 cwt/A. Seven of the 12 clones in the trial had higher marketable yields than Chieftain but were not statistically different. NY129 was the only clone to have an overall appearance rating of 7. Overall, internal defects were slight and only one clone, B1758-4, had incidence of soft rot at 10%. Culls were due mostly to silver scurf, misshapes, growth cracks, and skin blemishes attributed to Rhizoctonia.

Unreplicated Trial. (Tables 7a and 7b)

Sixty-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 high disease resistance will be evaluated in following years in replicated trials.

B. Breeding and Early Generation Selection Efforts

1. NCSU/USDA-ARS Early Generation Project. (8a and 8b and 9a and 9b)

This project, conducted in cooperation with Dr. Kathleen Haynes, USDA-ARS and funded in part by the USDA-CSREES, is an on-going experiment focused on: 1) developing improved potato breeding and selection methods for the eastern US; and 2) developing improved varieties more suitable to the range of climates and photoperiods found in the Mid-Atlantic and Southeastern U.S. In 2003, 31 clones remaining from two potato populations composed of multiple parents, and subjected to three years of selection in ME and NC during a four year period, were evaluated for the second time in replicated trials in Virginia, North Carolina and for the first time in New Jersey. The data for the two NC trials are summarized in Tables 8 and 9. The data from NC, NJ and VA will be summarized and presented elsewhere at the conclusion of the study in 2004. No clones in these populations are producing significantly higher yields than Atlantic, though several have produced equal yields. Several also have SG values approaching that of Atlantic with chip scores that are better. Two clones, B2133-18 (SG 1.081) and B2133-75 (SG 1.073), with marketable yields at 86% and 75% of Atlantic were given overall appearance scores of 8 and 9, respectively. Both of these clones received chip scores of 2 and both had lower IHN levels compared to Atlantic. Following this yearÕs study, the clones will be open for broader evaluation by other collaborators in 2004 if so desired.

USDA EG 20-Hills

Our third year selections are made on 20-hill plots. After this stage, the clones are placed in multi-state yield trials as described above. This year, 34 clones were planted and we selected seven in NC, and seven in ME with two clones being selected in NC and ME for a total of twelve clones remaining. Of the seven selected in NC six were selected in NC in 2002 and of those four were selected in NC during the 2001 single-hill harvest. Of those selected in ME six were selected in ME last year and three were also selected in ME from the 2001 single hills. B2273-75 was selected in both locations this season as well as at the six-hill level in 2002.

USDA 4-Hill Plots

This trial is an extension of our collaborative breeding efforts with the USDA-ARS. First year selections were made on single hills in 2002 in ME, and a single large tuber is then sent to us and cut into four seed pieces. This year 118 clones were screened and 19 were selected.

2. NCSU/Univ. of Maine and Cornell Early Generation Selection Projects

UM EG 4-Hill, 12-Hill and 20-Hill Plots Our collaboration with the University of Maine (UM) and Cornell University (CU) also supported by the USDA-CSREES, 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 and mirrors that of the UDSA four-hill trial. For 2003, 84 UM four-hill plots were sent to NC from ME and planted, and we selected two for further evaluation. Out of the ten 12-hill plots and twelve 20-hill plots sent from ME, one each was selected. These will be evaluated next year at the 12- and 20-hill plot level, and in our unreplicated trial, respectively.

From CU, we screened 38 clones in 12-hill plots and selected seven. These will be evaluated in 2004 as 20-hill plots. Typically a four-hill plot is also established but due to the exceptionally dry conditions last year in NY seed was not available.

3. NCSU Potato Variety Development Efforts

In 2002, we decided to initiate a small project to determine if the breeding program could maintain itÕs own breederÕs seed in eastern NC from year to year so we retained all first-year selections made in NC during July 2002 (167 clones in total) and planted them as six-hill plots in 2003. Eighteen clones were selected from this population and they will be planted as 20-hill plots in 2004. Results seem favorable to date as all clones tested for PVX, PVY, PVS, and PLRV have been negative. From the 8,364 single hills planted in 2003, 236 selections were made. They will be planted as six-hill plots in 2004.

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. Seed for the trials was provided by: Dr. Dave Douches, Michigan State University; Dr. Kathleen Haynes, USDA/ARS, Beltsville, MD; Dr. Walter De Jong Cornell University; Dr. Zenaida Ganga, University of Maine, University of Maine. Also a special thanks goes to Mr. Todd Bradley and the staff at Maine Farmers Exchange, Presque Isle, ME 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, the USDA-CSREES and the USDA-ARS. Their continuing support is much appreciated.