Simcoe: A new early-maturing,chipping potato variety

Simcoe, a round, white, early potato variety with excellent boiling, baking and chipping qualities, was released by the University of Guelph, Agriculture Canada and the Ontario Ministry of Agriculture and Food in 1981. Yield is comparable to that of Norchip while the chip color ratings and specific gravity are higher. Simcoe is resistant to mild mosaic and late blight, moderately resistant to common scab and moderately susceptible toRhizoctonia. It is susceptible to virus leafroll but resistant to net necrosis from current season infection.     

Somerset: A new chipping potato variety

The Somerset potato variety is a medium-maturing variety with attractive, round to oblong, white-skinned, white-fleshed tubers with shallow eyes. Its major use is expected to be as a chipping variety in areas where potatoes are stored for some length of time, since its sugar content is lower than most varieties during storage, and it can be chipped after six months in storage. Somerset does not show the net necrosis caused by potato leafroll virus, and is immune to race 0 of Phytophthora infestans (late blight). Somerset is also moderately resistant to infection by Alternaria solani (early blight), and is only moderately susceptible to Verticillium wilt. Somerset is more susceptible to both common and acid scab than Superior, but less susceptible than Kennebec and Katahdin. It also has shown susceptibility to skinning and shatter bruise, but does not have a strong blackspot bruise reaction.     

Amey: A multipurpose, russet-skinned potato cultivar for the Eastern United States

Amey is a late-maturing, russet-skinned, whitefleshed potato cultivar that yields more than Russet Burbank in most eastern United States potato production areas. Tubers of Amey are mostly oblong, occasionally long, with an evenly russetted skin. Tubers of Amey are smoother, more attractive, and have a much lower incidence of external defects than Russet Burbank. The specific gravity of Amey is equal to or greater than the specific gravity of Russet Burbank. French fries produced from Amey are lighter than or equal in color to those produced from Russet Burbank; however, tubers are frequently not long enough to satisfy the french fry industry. Baking and taste quality of Amey are excellent, and it has potential as a fresh market potato. Amey is resistant to race Rol of the golden nematode, powdery scab, and common scab. It is moderately susceptible to Verticillium wilt. It is susceptible to potato leafroll virus, late blight, and early blight.     

AC Ptarmigan: An early maturing potato cultivar with good chipping and fresh market quality

AC Ptarmigan is an early maturing, buff skin, cream flesh potato cultivar which has good, stable chip quality and can be processed directly from the field. The cultivar has uniform attractive tubers with shallow eyes. It is moderately resistant to common scab, early blight, potato virus Y and potato leafroll virus. It is susceptible to late blight and shows clear field symptoms when infected with bacterial ring rot.     

Krantz: A Russet cultivar for the irrigated sands

Krantz is an oblong to slightly blocky, russet-skinned potato cultivar with medium-late maturity and a vigorous vine. It is resistant to hollow heart, has high resistance to common scab and possesses high field resistance to late blight. It is moderately resistant toVerticillium wilt, susceptible to early blight, viruses S and X, and exhibits symptoms of bacterial ring rot. Krantz is adapted to the irrigated sands, but will growth crack in heavier soils.     

Conestoga: A new early potato cultivar with very good table and chipping qualities

Conestoga is an early, white-skinned potato with very vigorous early growth. It has very good boiling, baking and chipping qualities. Yield is comparable to that of Superior, with chip colour and specific gravity slightly higher than Norchip’s. Conestoga is moderately resistant to virus leafroll, net necrosis, early blight, and common scab and moderately susceptible to mild and rugose mosaic.     

Sentinel: An Early Yellow-Fleshed Potato Cultivar Suitable for Fresh Market and Chip Processing

Sentinel (FV8957-10) is a new yellow-fleshed potato cultivar that produces a high yield of attractive round to oval tubers at early harvest. Sentinel is suitable for fresh market use and chip processing. It was selected at the Lethbridge Research Centre of Agriculture and Agri-Food Canada, AB from a cross made at the Potato Research Centre of Agriculture and Agri-Food Canada, NB between breeding clones F72218 and F47024. Sentinel has erect medium-height vines and produces uniform tubers of medium-size with a light buff skin, light yellow flesh and shallow eyes. In multi-date-harvest trials, Sentinel produced similar or higher marketable yield compared to Atlantic and NorValley in southern Alberta. When harvested at 80 days after planting, Sentinel produced similar or greater yield than Superior and Conestoga at test sites across western Canada. Specific gravity of Sentinel was less than Atlantic and Conestoga but higher than NorValley and Superior, whereas chip colour was similar to Atlantic and lighter than NorValley or Superior. Sentinel showed little tendency to slough or to darken after cooking. It showed clear foliar and tuber symptoms when infected with bacterial ring rot. Sentinel is moderately susceptible to verticillium wilt, early blight, fusarium wilt and common scab and susceptible to late blight.     

Coastal Chip: A chipping potato variety resistant to heat stress

Coastal Chip is a medium-late maturing potato chipping variety suitable for production in locations along the east coast of the United States where heat stress reduces internal quality of tubers. It yields as well as the variety Atlantic but is not as susceptible to heat necrosis. The specific gravity of Coastal Chip averages approximately 0.010 less than Atlantic at locations subject to heat stress. In the seed producing areas of Maine it’s specific gravity averages approximately 0.005 less than that of Atlantic. Tubers are round, netted-skinned, and have moderately deep stem and bud ends. Chips from Coastal Chip are slightly lighter in color than those produced by Atlantic. In mid-Atlantic states where heat stress adversely affects chip color Coastal Chip processes into chips for a slightly longer period of time after harvest than does Atlantic. Glycoalkaloid content of Coastal Chip averaged 7.9 mg/100 g fresh tissue. Sunburned (green) tubers of Coastal Chip develop purple streaks that remain following processing. Hills must be properly covered to reduce losses. Coastal Chip is resistant to race A of the golden nematode (Globodera rostochiensis) and potato virus A. It is tolerant to Verticillium wilt, more susceptible to common scab and Rhizoctonia than Atlantic and susceptible to potato virus X.     

Islander: A golden nematode resistant potato variety for fresh market and chipping

The Islander potato variety is a medium maturing variety with oblong, shallow-eyed, white-skinned tubers. High dry matter and good chip color characterize this variety which is better adapted to Long Island, New York and New Jersey than to other northeastern areas. It is resistant to golden nematode and net necrosis; moderately resistant to common scab and early blight; and less susceptible than most varieties to acid scab and Rhizoctonia. The Islander is a product of the cross Chipbelle × Norchip.     

Mainestay: A high-yielding, round white potato variety for fresh market

The Mainestay potato variety is high-yielding and late-maturing producing attractive, round, white-skinned, white-fleshed tubers with medium-shallow eyes. Its major use is expected to be as a maincrop tablestock variety. Mainestay appearance ratings are similar to those of Katahdin, and greening in Mainestay tubers is less than in Kennebec. Most boil and bake qualities were rated equal to Katahdin in at least half of the tests, and Mainestay usually has a low incidence of internal defects. However, purple streak, heat necrosis, vascular discoloration, and heat sprouts have been seen on occasion. Mainestay tubers do not show the net necrosis caused by potato leafroll virus, and have shown very little hollow heart or blackspot bruising. Mainestay is susceptible to common scab and acid scab, but moderately resistant to verticillium wilt (Verticillium, albo-atrum andV. dahliae), early blight (Alternaria solani), rhizoctonia (Rhizoctonia solani), dry rot (Fusarium sambucinum), and pink rot (Phytophthora erythroseptica). It is moderately susceptible to the common race of late blight (Phytophthora infestans). Mainestay tubers are slow to mature after vine kill, and additional time is required prior to harvest in order to allow for proper periderm development and to reduce storage losses.     

St. Johns: A round white potato variety for fresh market

The St. Johns potato variety is high-yielding and late-maturing with attractive, round to oblong, white-skinned, white-fleshed tubers with mediumshallow eyes. Its major use is expected to be as a maincrop tablestock variety. Taste panels rated St. Johns better than or equal to Katahdin in texture, color, mealiness, and flavor. St. Johns tubers do not show the net necrosis caused by potato leafroll virus, and are resistant to golden nematode, corky ringspot, hollow heart, and blackspot bruising. St. Johns is also moderately resistant to greening, shatter bruise, verticillium wilt, early blight, common scab, the common race of late blight, leafroll,Fusarium sambucinum (dry rot) andErwinia carotovora (soft rot), although some breakdown has been reported in commercial storages. Symptoms of leafroll virus infection are somewhat difficult to detect.     

Prestile: A new round white potato variety

Prestile is a late maturing potato variety with attractive, round to oblong, white-skinned, white-fleshed tubers with shallow eyes. Its major use is expected to be for tablestock in areas where Katahdin and Ontario are now grown. Prestile tubers are slow to sprout in storage and do not show the net necrosis caused by potato leafroll virus, but are quite susceptible to heat necrosis. This variety is immune to potato virus X, and is moderately resistant to common scab (Streptomyces scabies), verticillium wilt (Verticillium albo-atrum), and early blight (Alternaria solani). Prestile is susceptible to skinning and shatter bruise, and is difficult to kill, particularly when heavily fertilized.     

Belrus: A new russet skin potato variety,combining high quality,pest resistance,and adaptation to the Northeastern United States and Florida

BelRus, a new russet potato variety, is medium late in maturity and adapted primarily for the Northeastern United States and northern Florida. Tubers are long, smooth and moderately flat with a heavy russet skin. Eyes are shallow and immediately adjacent skin is, for the most part, nonrussetted in the Northeastern U.S. Industry speaks of the BelRus there as the “white eyed russet.” BelRus is slightly higher in specific gravity than ‘Russet Burbank’, has a superior flavor when baked, and yields excellent french fries and flakes. Glycoalkaloid content of BelRus is quite low, being about 2 mg/100 g fresh tissue. BelRus is immune to virus A and tuber net necrosis; highly resistant to tuber heat necrosis, northern root knot nematode (Meloidogyne hapla), and the pinkeye bacterial disease; moderately resistant to scab, Verticillium wilt, leaf roll and potato virus Y. It is not resistant to either late blight or early blight, or viruses M, S, and X. Necrotic spotting of the foliage occurs following periods of high temperature and extended drought. BelRus has demonstrated high tolerance to bruising and storage rots incurred during harvest and handling. Shrinkage in bulk storage has been minimal. BelRus is recommended to be planted at about 25 cm (10 inches) in-the-row on 90 cm (36) rows with about 215 kg (180–200 lbs/acre), N₂/ha in-the-row.     

Defender: A high-yielding, processing potato cultivar with foliar and tuber resistance to late blight

The potato cultivar Defender is high-yielding, white-skinned, and notable for having foliar and tuber resistance to late blight infection caused byPhytophthora infestans (Mont.) de Bary. It was released in 2004 by the USDA-ARS and the agricultural experiment stations of Idaho, Oregon, and Washington. Defender is suitable for processing into french fries and other frozen potato products directly from the field or from storage. Defender also may be used for fresh markets in regions such as California, where cultivars with long tubers and white skin are traditionally grown. Resistances to late blight and other potato diseases make Defender an ideal candidate for organic potato production. Defender consistently produced greater total and U.S. No. 1 yields than ‘Russet Burbank’ in Idaho trials. In early harvest trials conducted in the western U.S., average total yields of Defender were 17% and 23% greater than yields for ‘Ranger Russet’ and ‘Shepody’, respectively. In full-season trials conducted in the western U.S., Defender averaged 10% and 15% higher yields than Ranger Russet and Russet Burbank, respectively. Specific gravity of Defender is consistently high, with values comparable to those of Ranger Russet; tuber ascorbic acid (Vitamin C) levels are also high. In addition to late blight, Defender also is resistant to tuber early blight (Alternaria solani, (Ellis & G. Martin), L.R. Jones & Grout), potato virus X, and net necrosis; it has moderate levels of resistance to Verticillium wilt (Verticillium dahliae, Kleb), pink rot, foliar early blight, corky ringspot, and Erwinia soft rot. Defender is susceptible to scab (common and powdery) and potato leafroll virus; it has moderate susceptibility to dry rot (Fusarium spp.) and potato virus Y. Susceptibilities to internal necrosis, tuber greening, and blackspot bruise also have been noted, but may be minimized through cultural and harvest practices.     

Quantitative analysis of host resistance,fungicide and weather effects on potato early and late blight using computer simulation models

Models which simulate the development of potato early blight, potato late blight and fungicide dynamics were used to analyze the effects of host resistance, fungicide and weather on individual and combined epidemics of these diseases. Fungicide and host resistance effects were based on (and accurately reflected) products and cultivars available to commercial potato growers in northeastern USA. Moderate resistance to early blight had a 2-3 fold greater effect than did moderate resistance to late blight in suppressing early and late blight, respectively. Analysis of simulation experiments indicated that replacement of an early blight susceptible cultivar with a cultivar moderately resistant to the disease would permit a reduction in the fungicide application frequency from once every week to once every two weeks without loss of disease suppression. Fungicide effect in suppressing late blight was 2-3 fold greater than in suppressing early blight. Variation in seasonal weather (typical of northeastern USA) influenced late blight development more strongly than it affected early blight development, and it affected epidemics of individual diseases more than combined epidemics.     

Yield Response of Potato (<Emphasis Type="Italic">Solanum tuberosum L</Emphasis>.) Genotypes to Late Blight Caused by <Emphasis Type="Italic">Phytophthora infestans</Emphasis> in Uganda

Potato (Solanum tuberosum L.) is a major food and cash crop, mainly grown by small-scale farmers in the highland regions of Uganda. Potato late blight is one of the major diseases limiting production with potential yield losses over 70%, making host resistance a strong element in integrated disease management. This study was carried out to screen and select high yielding potato genotypes with resistance to late blight in Uganda. Forty-eight genotypes, including advanced clones from the population B3C2 of the International Potato Centre, commercial and farmers’ varieties, were evaluated under two environments for two seasons. Trials were laid out in an 8?×?6 alpha lattice design with three replications. Genotypes showed significant differences in yield and resistance to blight. A higher disease severity was observed in Karengyere (56%). The average RAUDPC (= 100 max) across locations indicated that genotypes 395,077.12 and 392,657.8, with disease severity of 12% and 14%, respectively, were the most resistant. Genotypes Victoria (53%) and NKRN59.124 (48%) were the most susceptible. Mean tuber yield under late blight infection was19.8 t ha^?1. The best yielding genotype across sites was 395,112.32 (35.6 t ha^?1) while 394,905.8 (10.3 t ha^?1), yielded the lowest. The mean marketable tuber weight was 8.9 kg with genotypes 395,112.32 and 395,109.34 having the highest marketable weight of 16.5 kg and 15.6 kg respectively. Correlations between yield and yield related parameters were positive (p ≤?0.001), while those between RAUDPC were negative. The following genotypes, 395,112.32, 391,919.3, 393,220.54. 393,077.54, 396,038.107. 392,657.8, Kinigi, 395,014.17, NKRN59.58, NKRK19.17 and 395,011.2, were identified as promising parents for a late blight resistance breeding program. These exhibited high to medium resistance to late blight disease and high yields.     

Redsen: A new bright red-skinned potato cultivar

Redsen is a smooth, round, bright red-skinned potato cultivar with medium to high yield potential. It has resistance to race 0 of late blight (Phytophthora infestons) and is moderately resistant to some strains of silver scurf (Helminthosporium solanum) and common scab (Streptomyces scabies). The red color resists fading during storage and Redsen retains excellent marketability during storage.     

QTL Analysis of Late Blight Resistance in a Diploid Potato Family of Solanum spegazzinii × S. chacoense

Several quantitative trait loci (QTL) for resistance to late blight have been reported in diploid potatoes. The diploid wild potato species Solanum chacoense possesses a high degree of horizontal resistance to late blight. In the present study, we report on QTL mapping for late blight resistance in a diploid mapping population of 126 F₁ of Solanum spegazzinii (susceptible) × S. chacoense (resistant). The area under the disease progress curve (AUDPC) values for late blight resistance using the “whole plant in vitro assay” and the “detached leaf assay” on the mapping population displayed quantitative variation. Out of 64 AFLP primer-pairs combinations and SSR markers, a total of 209 significant AFLP loci were placed onto the 12 linkage group of potato covering a total map length of 6548.1 cM. QTL analysis based on the AUDPC dataset of the “whole plant in vitro assay” using the interval-mapping option identified two QTL (LOD?>?2.5) located on linkage groups IX and X, which explained 14.70 and 3.40% variation, respectively. The present study revealed the presence of potential new genetic loci in the diploid potato family contributing to quantitative resistance against late blight.     

Ivory Crisp: A potato variety with high tuber solids and cold chipping ability

Ivory Crisp was released in 2002 by the experiment stations of Idaho, Oregon, Washington, and North Dakota, and by the USDA/ARS. It resulted from a 1980 cross of ND292-1 and A77268-4. Ivory Crisp is suited for use in both the direct delivery and storage chipping markets. Ivory Crisp is a medium-maturing potato variety with round, white tubers and excellent chipping quality. It has medium to high yield potential, high tuber solids, resistance to most internal and external tuber defects, and the ability to chip from cold storage. In trials in Idaho, Oregon, and Washington, total and U.S. No. 1 tuber yield of Ivory Crisp was similar to Atlantic but lower than Chipeta. Yield of tubers in the size range 113–336 g for Ivory Crisp is higher than for either Atlantic or Chipeta. Ivory Crisp is resistant to growth cracks, secondary growth, hollow heart, and stem-end necrosis, but susceptible to shatter bruise. Tuber sugar content has consistently remained low following cold storage and near-acceptable chip color retained at 4.4 C. Ivory Crisp is susceptible or moderately susceptible to most common field diseases of potato. It is highly susceptible to common scab, powdery scab, and pink rot. Tubers of Ivory Crisp have dry matter content (22.4%) lower than those of Atlantic, but higher than those of Chipeta. Glycoalkaloid content of Ivory Crisp tubers is very low (4.3 mg 100 g^-1). An application for Plant Variety Protection has been filed for Ivory Crisp. Seed is available from potato seed growers in Idaho, North Dakota, and Canada. Small amounts of seed, for research purposes, can be obtained by contacting the corresponding author.     

Yukon Gold: A new yellow-fleshed,medium-early,high quality table and French-fry cultivar

Yukon Gold is a medium-early, yellow-fleshed potato cultivar with very good boiling, baking, and French-frying quality. It is not suitable for chips. In Ontario its yield is similar to Russet Burbank’s. Plants are susceptible to virus Y and slightly susceptible to virus leafroll but are resistant to mild mosaic. Tubers are moderately susceptible to common scab,Streptomyces scabies.