Progress Report to the Maine Potato Board Research Subcommittee

January 12, 2006

 

Project Title:

 

            New Potato Variety Evaluation (Challenge Grant Program and Grower Trials)

            2006 Growing Season

 

Investigators:

 

Gregory A. Porter and Paul C. Ocaya; Dept. of Plant, Soil & Environmental Sciences.

 

Executive Summary:

 

            This project uses small-plot trials to select potato breeding lines with commercial potential for Maine growers and then facilitates commercial-scale grower trials of these promising lines.  The grower trials provide important information on successful management practices and experiences growing, storing, and marketing the new varieties.  This project, along with Challenge grants provided by the Maine Department of Agriculture, helps support the potato variety development efforts of commercial potato growers in Maine.  During 2006, small-plot variety trials were conducted at three locations in Maine (Exeter, central Maine; Presque Isle, central Aroostook; St. Agatha, northern Aroostook).  These trials were used to screen 170 new potato breeding lines of which only a few will be selected for commercial-scale evaluation. 

 

During 2006, commercial-scale trials of one russeted fresh market and french fry processing clone (Blazer Russet), three chippers (Beacon Chipper, Dakota Pearl, AF2211-9), one fresh market round-white clone (AF1758-7), two reds (NDTX731-1R and NY129), and one purple-skinned, yellow-fleshed specialty clone (B1816-5) were conducted as part of the new potato variety challenge grant program.  We allocated a total of $10,500 in Challenge grants (funding provided by the Maine Department of Agriculture) directly to growers in support of these commercial tests.  The grants went to 12 different growers (14 individual trials) and represented 53 acres of production.  All growers have submitted a detailed report of management practices, yield, quality, and pest incidence.  Each of the growers has been interviewed via phone or will be after the potatoes are moved from storage.  

 

The grower trials of Beacon Chipper, Dakota Pearl, and AF2211-9 generally gave positive results for chipping.  Based on the commercial trial results and our small-plot research, I am particularly impressed with Beacon Chipper.  AF2211-9 was high yielding in northern Maine during 2006, but performed poorly in Central Maine trials.  It had scab problems at all three locations.  AF1758-7, a fresh market round white with good disease resistance, has done well in 5 of 6 commercial-scale trials conducted over the years.  It did well in two commercial trials in 2006, but had rot problems in a 1-acre commercial trial.  B1816-5, a purple-skinned, yellow-fleshed, specialty variety will be named in 2007.  It did reasonably well in three small commercial trials during 2006 and should provide small-scale growers with unique marketing opportunities.  NDTX731-1R is a high yielding red with a nice, bright skin and good external and internal tuber quality.  It has done well in commercial-scale trials in 2005 and 2006.  It does develop skin netting under wet soil conditions and there is some concern that this will result in inconsistent appearance for the red-skinned fresh market.  NY129, another high yielding red with a low incidence of external defects, did not do so well in its 2006 commercial-scale trial.  It was a bit too late, did not yield as well as expected, and also developed some skin netting.

 

Project Objectives:

 

            1.         To test new potato selections on commercial farms at three different locations in Maine.

 

            2.         To provide technical support for growers conducting commercial-scale tests of new varieties (in support of new variety development and challenge grants provided to growers).

 

Grant Received:

 

            $7,864

 

Accomplishments to Date:

 

     Small-plot Trials on Commercial Farms.  Small-plot variety trials were conducted in central Maine (Exeter, Crane Farms, 37 lines and varieties) and northern Aroostook County (St. Agatha, Labrie Farms, 84 lines and varieties).  This work compliments trials conducted at Aroostook Research Farm in Presque Isle. The central Maine trial is focused largely on selection for chipping use.  The St. Agatha site is a selection site for russets, french fry processing types, reds, and round-whites. It provides a great trial for common and powdery scab resistance and susceptibility.  A summary of promising lines is present below and a detailed report from these small-plot variety trials is available upon request.   The data are used in combination with data from Aroostook Research Farm and other trials around the eastern United States.  The small-plot data are used to help the Maine, USDA-ARS, and New York breeding programs make decisions about lines that are worthy of entry into regional and commercial trials.  The results are also used in variety descriptions and management profiles.

 

            Selections that performed particularly well in the regional and advanced trials in 2006 and recent years were:

 

Chipping

Beacon Chipper    slightly netted skin, round to oblong tubers, medium maturity, good yield and specific gravity, moderate tuber size, moderate scab resistant, good chip color, promising

AF2291-10             smooth to slightly netted skin, round to oblong tubers, medium-late maturity, high specific gravity, moderate to good yields, large tuber size, generally good appearance but can be prone to off shapes, scab resistant, good chip color, moderate resistance to shatter bruise, susceptibility to blackspot bruise is similar to Snowden,  promising

AF2497-2               late, round to oblong, scab resistant, smooth skin, appearance is fair to good, moderate gravity, good chip color, yields are OK so far, needs further testing.

B0766-3                  medium maturity, round to oblong, slightly netted skin, moderate scab resistance, appearance is good, moderate to large tubers, moderate gravity, yields typically 90 to 95% of Atlantic, very good chip color, hollow heart susceptibility similar to Atlantic, promising, needs commercial testing.

B1992-106              netted skin, round to oblong tubers, medium to medium-late vine maturity, moderate to good yields, high specific gravity, fair appearance, good chip color in 2006, but yields weren’t as good under very wet conditions in 2006 as they had been in 2005, needs further testing.         

NY139                    medium to medium-late, round to oblong, scab resistant, slightly netted to smooth skin, appearance is good, moderate to large tubers, good gravity, good chip color, may be resistant to shatter bruise, promising.

 

Fresh market whites

AF2291-10             potential dual-purpose, see chipping section, promising

AF2376-5               pretty, smooth skin, pale yellow flesh, late maturity, moderate to high yields, moderate tuber size, high specific gravity, resistant to shatter bruise

AF2497-2               see above

AF2574-1               late, oblong to round, netted to slight net, scab resistance, large tubers, fair appearance, good yields, moderate specific gravity, needs further testing.

NY126                    moderately smooth skin, pale yellow flesh, oblong to round tubers, medium to medium-late maturity, very good yields, moderate specific gravity, very good boiled and baked, resistant to blackspot, good scab resistance, relatively few pickouts, very promising, needs commercial testing.

 

Russets or Long Whites

GemStar Rus.        (A9014-2) medium russeted skin, long tubers, medium-late maturity, fair to good appearance, can process for fries, possible dual-purpose, resistant to blackspot, good boiled and baked quality, hollow heart susceptibility can be a problem, reportedly does not express foliar PVY symptoms.

AF2413-4               netted to light russet, decent appearance, oblong to long tubers, medium-early to medium maturity, moderate gravity and yields, can process,  needs further testing.

W2683-2Rus         see below

 

French Fry Processing

GemStar Rus.        see above

AF2413-4               see above

AF2426-1               netted, large tubers, long tuber type, scab resistant, medium to medium-late, can yield well, not pretty enough for fresh use, fry color is OK, but specific gravity may not be high enough

W2683-2Rus         late maturing russet, appearance is fair to good, scab resistant, moderate specific gravity, acceptable yields, variable size, good fry color, needs further testing.

 

Specialty

AF2376-5               pale yellow flesh, see above

AF2393-7               nice red skin, pretty, smooth to slightly netted, round to oblong, small tubers, pale yellow flesh, few external defects, early maturity, yields like Dark Red Norland

B0984-1                  red skin, nice color, moderately smooth to slightly netted skin, white flesh, round to oblong, moderate to high gravity, mid-season to late maturity, pretty, moderate tuber size, might work if a market wanted a high specific gravity red

B1816-5                  purple with yellow flesh, medium purple skin color, slightly netted to moderately smooth skin, round to oblong, moderate gravity, early to medium maturity, fair to good appearance, small tuber size, low to moderate yields, susceptibility to skinning may be a problem, promising for speciality market and is being released in 2006/2007.

B2152-17                nice red skin, slight net, medium maturity, yellow flesh, round, small tubers, few external defects, yields like Dark Red Norland, needs further testing.

B2327-2                  nice red skin, pretty, smooth skin, medium maturity, white flesh, round, small tubers, few external defects, yields like Dark Red Norland, needs further testing.

NDTX731-1R        red skin, nice color, skin can range from smooth to slightly netted to netted, medium to medium-late maturity, very good yields, moderate to large tubers, low to moderate gravity, very pretty, white flesh, few pick outs, acceptable boil and bake scores, ready for commercial testing, promising

 

 

     2006 Challenge Grants and Commercial Trials.  In addition to the support provided by the Maine Potato Board, the Maine Department of Agriculture provided $10,500 to support challenge grants directly to growers.   Commercial-scale trials of one french fry processing clone (Blazer Russet), three chippers (Beacon Chipper, Dakota Pearl, AF2211-9), one fresh market round-white clone (AF1758-7), two reds (NDTX731-1R and NY129), and one purple-skinned, yellow-fleshed specialty fresh market clone (B1816-5) were conducted as part of the new potato variety challenge grant program.  We allocated a total of $10,500 in Challenge grants (funding provided by the Maine Department of Agriculture) directly to growers in support of these commercial tests.  The grants went to 12 different growers (14 individual trials) and represented 53 acres of production.  

 

All growers have submitted a detailed report of management practices, yield, quality, and pest incidence.  Each of the growers has been interviewed via phone or will be after the potatoes are moved from storage.  Later in the storage season, I will check with some of the growers to learn about their additional storing and marketing experiences with the new varieties.   Table 1 summarizes the status of each line in the 2006 program.   A brief summary of 2006 grower reports is presented in Table 2.

 

           

 

Table 1.           Current status of experimental potato lines in the 2006 New Potato Variety Challenge Grant Program.

 

Beacon Chipper   Unknown parentage, slightly netted skin, round to oblong tubers, medium maturity, good yield, moderate to high specific gravity, moderate tuber size, moderate scab resistance, good chip color from the field and storage.  A promising chipping variety for Maine based on 2006 small-plot trials, commercial testing conducted in Maine during 2006, and commercial tests conducted before it was named.  It has been entered in the Eastern Regional Potato Variety trials for 2007. A recent release from Michigan and Maine.

 

Blazer Russet      A cross between A7816-4 and NorKing Russet.  A fresh market and processing russet from the Pacific Northwest.  It reportedly has good resistance to common scab and more resistance to fusarium and PVY than Russet Burbank.  Western research suggests greater susceptibility to tuber early blight and foliar late blight than Russet Burbank.  It was tested in one commercial trial during 2006 with good results, but the variety needs a full-season test for fresh or processing market to judged its potential.  In two Maine small-plot trials during 2006, it had yields that were competitive with Russet Burbank, comparable specific gravity, small to medium tuber size, acceptable fry color, and good external quality.  Appearance was better than Russet Burbank, but not as good as Russet Norkotah.  Hollow heart problems were observed in one of the trials.   

 

Dakota Pearl        A chipping selection from North Dakota State University.  Tubers are round, smooth, and shallow-eyed with a white skin.  Yield and gravity are typically moderate.  Vine maturity is early to medium-early.  It chips well from storage.  Yields are reportedly inconsistent.   Good results in a large-scale, 2006 commercial trial.  Pretty appearance and good chip color.

 

AF1758-7              A fresh market, round white from the University of Maine.  It has round tubers, white smooth to netted skin, and good external appearance.  It is resistant to net necrosis, golden nematode, verticillium wilt, early blight, corky ring spot, common scab, blackspot bruise, and hollow heart.     US#1 yields in small plot trials have been much better than Katahdin.  It has a low incidence of external defects at northern site, but does not perform well in the southern coastal areas of the East.  It is low specific gravity variety, short tuber dormancy, susceptibility to shatter bruise, and very susceptible to foliar applications of metribuzin herbicide.  It has performed well in five commercial scale trials for seed and fresh market (two in 2006, one in 2005, and two in prior years).  It had rot problems in one 2006 1 acre commercial-scale trial for seed production. 

 

AF2211-9              A storage chipper from the University of Maine.  It has high specific gravity and good chip color from storage.  It has moderate yields, good tuber size, and resistance to net necrosis.  External defects (sunburn, scab) have caused problems in Maine small-plot trials.  Hollow heart has been a problem in other eastern locations.  It chipped and yielded well in two Maine commercial trials during 2006; however, scab problems were noted in both tests. 

 

B1816-5                                This specialty potato has a nice purple skin, yellow flesh, and is excellent boiled, roasted, or fried.   It is a specialty potato variety from the USDA-ARS in Beltsville that should create some unique marketing opportunities for small-scale production.  Three commercial tests were conducted during 2006 and these growers are still assessing the potential for developing a market for this variety which will be named in 2007.  Tubers are small, oblong, and usually attractive; however, growers can expect some off shapes, skin netting, and skin discoloration.  It is medium maturing with US#1 yields similar to Dark Red Norland.  Specific gravity is moderate (considerably higher than Dark Red Norland).  Tuber maturity is critical to prevent skinning and shatter bruise problems.

 

NDTX731-1R       Bright red skin, fresh market, medium to medium-late maturity, high yields, very good external appearance, low specific gravity, white flesh, and round tubers.   It has a low incidence of external defects.   It is resistant to common scab and has moderate resistance to powdery scab.  It has had acceptable boil and bake scores.  NDTX731-1R has had really good yields throughout the eastern region and it seems to have some tolerance to internal heat necrosis in those areas where this defect is a problem.  It was grown in commercial-scale trials in Maine during 2005 and 2006 and had high yields, good appearance, and packed well.  Because it has some skin netting under wet soil conditions there is some concern that the appearance won’t be consistently acceptable for fresh market.  It still appears to be worth continued evaluation for commercial use.

 

NY129                   Moderate to bright red skin, fresh market, medium-late to late maturity, high yields, good external appearance, white flesh, and round tubers.   It has a low incidence of external defects.   Skin netting can be a problem.  It is resistant to common scab and has had really good yields throughout the eastern region.  It was grown in its first commercial-scale trial in Maine during 2006, yields were not that high and tuber size was small.  The grower felt that it was a bit too late and that skin netting could be a problem, but it was successfully packed for fresh market.

 

 

     Variety Description and Management Profiles.  Variety descriptions and management profiles are being developed for the successful varieties in the 2006 program and for several promising breeding lines (see attached example for NDTX731-1R).  These profiles are developed based on breeding program data, small-plot yield trials, management experiments, and commercial experience.    The variety descriptions will be made available on a website and a list of available profiles will be made available to growers and the UM Cooperative Extension.  Hard copies of variety profiles will be sent to growers upon request.  

 

Future Plans :

 

            We hope to continue this program during the 2007 growing season with: 1) small-plot variety research trials conducted in Exeter, St. Agatha, and Presque Isle; 2) commercial challenge grants for the most promising lines identified from research trials.  Our goal is to support approximately 14 commercial trials during 2007 at $750 each.  We will again request support for the grower grants ($10,500) from the Maine Department of Agriculture.  The number of grants will be reduced proportionately depending on the level of grant support received and the number of commercial trials conducted.            We will continue to improve the focus of this program and to limit the commercial-scale tests to only the most promising lines based on research results.


Table 2.            Summary of Commercial Trial Results for the 2006 Challenge Grant Program.  Storage Reports from Growers are Pending.

 

Beacon Chipper (a storage chipper; good results, one commercial trial, 3 acres grower recommends 8 inch spacing, samples are being evaluated for chip quality)

 

                test #1                    chipping/seed                       Good emergence (90% stand), good late vigor

                                                3 acres                                    280 cwt/A, moderate size, good set, shallow eyes, appearance like Superior.  Good chipping prospect, samples placed in storage for chip color evaluation.

No external defect problems.  Late blight was present in this trial and in the surrounding area.

 

                                                                                                Planted: May 15 (seed cut and treated same day)

                                                                                                6.7-inch seedpiece spacing

                                                                                                130-130-160 fertilizer at planting

                                                                                                Harvested: September 13 (vinekilled at 92 days after planting)

Some stored at 38F for seed; some sent to chipping storages.

               

Blazer Russet (fresh market and processing russet; one commercial trial, good results, but the variety needs a full-season test for fresh or processing market to judged its potential)

 

                test #2                    russet/seed                           Good early growth (90+% stand), good late vigor

                                                1 acre                                     260 cwt/A, medium dark russeted skin, small, nice shape and appearance.  No problems observed except that grower noted that it was killed early for seed and that it needs a longer season

 

                                                                                                Planted: May 25 (cut and suberized 10 days before planting)

                                                                                                9-inch seedpiece spacing

                                                                                                113-170-170 plus 0-0-90 before cultivation

                                                                                                Harvested: September 11 (vinekill 88 days after planting)

Stored in wooden boxes at 38F seed.

               

Dakota Pearl (storage chipper; good results, one commercial trial, 40 acres, grower indicates that was pretty enough that it could be used for fresh market) 

 

                test #3                    chipping                                                Good emergence (85% stand), good late vigor

                                                40 acres                                  268 cwt/A, good tuber size and appearance, good chip color and gravity.  Some sunburn, rot, growth cracks, and other external defects. 

 

                                                                                                Planted: June 18 (seed cut and treated same day)

                                                                                                9-inch seedpiece spacing

                                                                                                130-130-130 fertilizer at planting (46 lbs N at cultivation)

                                                                                                Harvested: October 4 (vinekilled at 82 days after planting)

Stored in bins at 50F for chipping.

 

AF1758-7 (fresh market round white; good results in two commercial trials, 3 acres, and poor results in one commercial trial, 1 acre)

 

                test #4                    table                                       Good emergence (95% stand), good late vigor

                                                2 acres                                    360 cwt/A, good tuber size and appearance, only a few external defects, some black scurf caused appearance problems.  Marketed in 5 lb poly bags with good success.

 

                                                                                                Planted: April 22 (planted whole 1.5 to 2.25” seed)

                                                                                                9-inch seedpiece spacing

                                                                                                154-154-176 fertilizer at planting (plus 0-0-150 broadcast)

                                                                                                Harvested: September 19 (vinekilled at 114 days after planting)

Packed and shipped at harvest; not stored.

 

                test #5                    seed/table                              Good early growth (78% stand), better late vigor than Monona

                                                1 acre                                      bright round tubers, medium size, very few external defects. 

 

                                                                                                Planted: May 12 (fresh cut with seed treatment) 

                                                                                                8-inch seedpiece spacing

                                                                                                180-130-180 at planting

                                                                                                Harvested: September 13 (vinekilled at 98 days after planting)

Stored in a bin for use as seed.

 

                test #6                    seed/table                              Good early growth (85+% stand), good late vigor

                                                1 acre                                      180 cwt/A, good appearance and tuber size, a few external defects, severe rot problems, possibly pink rot. 

 

                                                                                                Planted: May 13 (hand cut and suberized) 

                                                                                                9.5-inch seedpiece spacing

                                                                                                168-168-168 at planting

                                                                                                Harvested: September 13 (vinekilled at 97 days after planting)

Stored in a pallet boxes for use as seed.

 

AF2211-9 (storage chipper; generally good results in both commercial trials except for concerns about scab)

 

                test #7                    chipping                                                Good emergence (90% stand), good late vigor

2 acres                                    295 cwt/A, moderate size, bright, nice shape, powdery scab problems observed, no other external defects.   Chipped from the field at harvest with good results.  One pass hilling was used prior to emergence.  Grower reported that the yields were good considering the weather.  He would try it again on a field that did not have a powdery scab history. 

 

                                                                                                Planted: May 13 (seed cut and treated same day)

                                                                                                7.5-inch seedpiece spacing

                                                                                                150-130-180 fertilizer at planting

                                                                                                Harvested: September 12 (vinekilled at 99 days after planting)

Chipped from field, no storage results.

 

                test #8                    chipping                                                Good emergence and stand, weak late vigor due to corn borer.

2 acres                                    280 cwt/A, good size and appearance, few external defects.  Grower indicated that some scab was present, but that most everything that he grew had scab this year.  The grower also felt that it was more susceptible to corn borer than his other varieties, but out-yielded them despite this.  He noted that some blackspot problems were observed in a load that sat for a few days prior to delivery. 

 

                                                                                                Planted: May 25 (seed cut and treated same day)

                                                                                                8-inch seedpiece spacing

                                                                                                168-168-192 fertilizer at planting

                                                                                                Harvested: September 6 (dug green, 104 DAP)

Chipped from field, no storage results.

 

 

B1816-5 (specialty fresh market, purple skin and yellow flesh; great for boiling and frying, generally good results in three commercial trials, but success depends on market reception to purple-skinned variety; growers liked the appearance but noted that tuber size is small.  Some skinning problems and silver scurf problems were observed)

 

                test #9                    fresh market                          Good emergence (95% stand), good late vigor

<1 acre                                   12:1 increase, small to medium size, very good appearance, very few external defects, no storage problems to date.  Small tuber size was the only concern noted.  Grower notes that it is very pretty, great for frying and boiling.  Market reception to this unusual potato remains to be determined. 

 

                                                                                                Planted: May 28 (seed was cut, no seed treatment)

                                                                                                10-inch seedpiece spacing

                                                                                                organic production system

                                                                                                Harvested: September 22 (no vinekill)

Stored in barrels, old potato storage.

 

                test #10                  fresh market                          Good emergence (90% stand), good late vigor

<1 acre                                   fair yield, small to medium size, good appearance, very few external defects, but noted moderate skinning even though vines were dead.  Small tuber size is a problem, but it has nice purple skin color.  Consumers who try it seem to like it. 

 

                                                                                                Planted: May 1 (seed was cut by hand and treated)

                                                                                                9-inch seedpiece spacing

                                                                                                120-180-180 at planting

                                                                                                Harvested: not reported (vinekill approx 115 DAP)

Storage not reported.

 

test #11                  fresh market                          Good emergence (100% stand), good late vigor

<1 acre                                   small to medium size, good appearance, but problems noted from skinning, silver scurf, and rot due to late blight.  Grower notes that it adds marketing opportunities due to purple-skin and yellow flesh.  Market beside Yukon Gold as “Bluegold”.

 

                                                                                                Planted: May 8 (seed was cut, no seed treatment)

                                                                                                10 to 12 inch seedpiece spacing

                                                                                                organic production system

                                                                                                Harvested: October 1 (no vinekill)

Stored in bags in a cellar.

 

NDTX731-1R (red skin, white-fleshed fresh market selection; it did well in both commercial tests, very good skin color, skin netting can be a problem under some conditions)

 

                test #12                  fresh, red skin                       Very good early vigor (90+% stand), good late vigor,

                                                <1 acre                                   366 cwt/A, nice round appearance and bright color, some skin netting, medium sized, low external defects incidence.

Packed for fresh market, the only concern noted was that the skin netting detracted from appearance.

 

                                                                                                Planted May 28 (fresh cut and treated)

                                                                                                8.5-inch seedpiece spacing

144-66-125 at planting plus 2 GPA foliar UAN                               

Harvested: September 19 (92 days planting to vinekill)

Stored in boxes, suberized 55F for two weeks then cooled.


                test #13                  seed, red skin                        Very good early vigor (100% stand), good late vigor,

                                                <1 acre                                   90:1 return from minitubers, nice round appearance, darker red than Dark Red Norland, medium-large sized, low external defects incidence, some skinning, stolons were present at harvest.   Grower plans to hold down fertilizer rate in the future.

 

                                                                                                Planted May 13 (minitubers)

                                                                                                12-inch minituber spacing

113-170-170 at planting (0-0-90 before cultivation)

Harvested: September 11 (91 days planting to vinekill)

Stored in boxes.

.

 

NY129 (red skin, white-fleshed fresh market selection; it did well in both commercial tests, very good skin color, skin netting can be a problem under some conditions)

 

                test #14                  fresh, red skin                       Good early vigor (90+% stand), very good late vigor,

                                                <1 acre                                   272 cwt/A, good appearance and color, some skin netting, small tubers, low external defects incidence.

Packed for fresh market, the concerns noted were late maturity, skinning, and skin netting which detracted from appearance.

 

                                                                                                Planted May 28 (fresh cut and treated)

                                                                                                8.5-inch seedpiece spacing

144-66-125 at planting plus 2 GPA foliar UAN                               

Harvested: September 19 (92 days planting to vinekill)

Stored in boxes, suberized 55F for two weeks then cooled.


NDTX731-1R -- Potato Variety Profile1

The University of Maine Potato Variety Development Project

Draft date: January 11, 2005; updated January 12, 2007

                                                                                               

Parentage:      ND169-10R x ND9476-5R

Breeder:         Texas A & M Potato Breeding Program; College Station, TX

Release Date: n/a

 

Description:    Medium to Medium-late maturing, red-skinned fresh market line

 

Plant Characteristics:

            Type                       moderately large-sized tops (slightly smaller than Chieftain)

                Maturity:               medium to medium-late (similar to slightly earlier than Chieftain)

                Flowers                  purple

 

Tuber Characteristics:

            Shape                     mostly round, attractive shape

                Eyes                       shallow

                Skin                        bright red, typically a slight net, can be moderately smooth 

                Flesh                      white

 

Resistances/Susceptibilies:

                Common scab                       good resistance

                Powdery scab                       moderate resistance

Susceptible to early blight, late blight, and other diseases tested to date.  Intermediate blackspot bruise susceptiblity. 

 

Maine Small-plot Trial Results (Presque Isle and St. Agatha):

            U.S.#1 Yields                        96% of Chieftain (average for 12 site-years, 2003-2006)

                                                                124% of Dark Red Norland (average for 8 site-years, 2003-2006)

                Appearance                          external appearance better than Chieftain or Dark Red Norland

                Specific gravity                    averaged 1.066, 0.001 less than Dark Red Norland and 0.005 less than Chieftain

                Tuber size                              moderate to large, usually larger than Dark Red Norland and slightly smaller than Chieftain

                External defects                    low incidence, a few misshapen, growth cracked, and sunburned tubers

4.7% over 12 site-years (Dark Red Norland averaged 7.4%)

                Hollow heart                         1.25% versus 0% for Chieftain and 1.25% for Dark Red Norland

                Chip color                              not acceptable for chipping

                Cooking tests                       acceptable for boiling and baking; this is a low specific gravity potato

 

Regional NE1014 Small-plot Trials (Canada to Florida)2:

            U.S.#1 Yields                        108% of Chieftain (average for 36 site-years, 2003-2005)

                Appearance                          external appearance better than Chieftain or Dark Red Norland

                                                                Slight netting on skin can be a problem

                Specific gravity                    averaged 0.005 less than Chieftain

                Tuber size                              moderate, usually similar to or slightly smaller than Chieftain

                External defects                    usually low incidence, a few misshapen, growth cracked, and sunburned tubers

36 site-years: 5.8% versus 7.0% for Chieftain and 5.5% for Dark Red Norland

                Hollow heart                         0.8% versus 1.0% for Chieftain and 0.8% for Dark Red Norland

                Internal necrosis                  1.5% versus 13.4% for Chieftain and 0.8% for Dark Red Norland

                Chip color                              not acceptable for chipping

                Cooking tests                       Acceptable boiled and baked.  This is a low specific gravity potato.

Dormancy and Small-scale storage tests3:

                        Maine tests:        Moderate dormancy, slightly shorter than Chieftain

                                                Weight loss 5-mo. @38F:   6.0% (Chieftain, 4.6%, Dark Red Norland, 5.9%)

                                                Weight loss 5-mo. @50F:   18.2% (Chieftain, 18.7%; Dark Red Norland, 35.6%)

 

Maine Challenge Grant Results:

                        Good results in a small fresh market trials during 2005 and 2006; however, netting can detract from the fresh market appearance of this clone when wet soil conditions occur.

                       

Management Suggestions:

            Fertilizer:                Suggest low to moderate nitrogen rates, approximately 120 to 150 lbs/A, but may adjust depending on soil conditions and crop rotation.  The lower end of this range will likely help in short-season growing regions.  Avoid excessive fertilizer so that normal maturation and skin set can occur prior to harvest.

                Spacing:                 7-8 " seed and table

                Other:                     Allow plenty of time between vinekill and harvest to allow proper skin set.

 

1Results presented reflect current information available at the time of printing and is based on both research results and commercial trials.  The information will need to be updated as more trials are conducted.  For more information see the release publication (if  noted above), contact the originating breeding program, or contact Greg Porter, 5722 Deering Hall, Room #114, University of Maine, Orono, ME 04469 (207-581-2943).

 

2Growing conditions vary widely around the eastern region and performance in a particular area may be different from the average results.  See the annual trial reports or contact Greg Porter, 5722 Deering Hall, Room #114, University of Maine, Orono, ME 04469 (207-581-2943) for more information about performance at a specific location.

 

3Storage screenings indicate relative differences among varieties and do not guarantee “storage capability” under commercial conditions.  Commercial “storage capability” will depend on growing conditions, harvesting and handling practices, pest management, storage size and management, etc.  The reported weight-loss values were generated from tubers that did not receive any sprout inhibitors.