ALHAMRA,STEMSTER, SKIRZA: Three new cultivars from Caithness,Scotland

A new private potato breeding company was established in Caithness, Scotland in 1983. In August 1986 the first three potato varieties from ‘Caithness Potato Breeders Ltd.’ were accepted onto the United Kingdom National List of Potato Varieties. These three cultivars—ALHAMRA (maincrop), STEMSTER (maincrop), SKIRZA (second early), are all red-skinned and result from a cross between ‘Desiree’ and ‘Maris Piper’. All three cultivars have demonstrated high yield potential, ‘Stemster’ particularly so, and all are resistant to one pathotype of the golden (potato cyst) nematode, unlike ‘Desiree’ their red-skinned parent.     

Dakota rose: A bright red tablestock potato cultivar that retains its skin color in storage

‘Dakota Rose’ is a medium-maturing, white-fleshed, red-skinned cultivar that retains its bright red color in storage. Tubers have very smooth skin with an oblong shape. Yields are equivalent, or superior, to ‘Red Norland’, but lower than ‘Red Pontiac’, a late-maturing cultivar. Dakota Rose produces a high percentage of U.S. No. 1 tubers and few oversized tubers. Sensory evaluation scores for baked, boiled, and microwaved potatoes are similar to Red Norland and Red Pontiac, standard red tablestock cultivars. The specific gravity averaged about 1.067 across irrigated and non-irrigated sites, a typical value for a red tablestock cultivar. Adequate skin set for handling has often been difficult to achieve; application of nitrogen early in the growing season, coupled with chemical vinekill 3 weeks prior to harvest aids in minimizing the problem. Dakota Rose was released by the North Dakota Agricultural Experiment Station on 17 November 2000.     

Influence of Growth Regulators on Plant Growth, Yield, and Skin Color of Specialty Potatoes

2,4-D has been used since the 1950’s to enhance color in red-skinned potatoes, but there is little research on the potential use of other plant growth regulators to improve tuber skin color in the wide range of specialty potatoes now available on the market. Field trials conducted at Parma, ID in 2009 and 2010 evaluated the effect of foliar applications of 2,4-D, NAA, and LPE on plant height, foliar injury, tuber yield, size distribution, and skin color of six specialty potato cultivars. Skin color was rated visually and via HunterLab colorimeter at harvest, and again after storage (132 days in 2009 and 93 days in 2010) at 4 °C and 95 % R.H. 2,4-D caused slight foliar injury and reduced tuber size in all cultivars. It also increased visual skin color rating in the red-skinned cultivars ‘Red LaSoda’ and ‘TerraRosa’ at harvest and after storage, and influenced incidence of pink coloration around the eyes of ‘Yukon Gem’ tubers, but did not affect color of blue/purple-skinned cultivars. NAA and LPE did not consistently influence plant growth, yield, tuber size or visual skin color in any cultivar. Colorimetric evaluations mostly agreed with the visual ratings, and indicated that storage significantly altered skin color in all cultivars, regardless of growth regulator treatment.     

Alasclear: A high quality scab resistant potato

Alasclear was released from the breeding program at Palmer to provide Alaskan potato growers with a variety as resistant to potato scab as Ontario and of much better quality than that variety. Alasclear has a clear skin and is very acceptable at harvest for chip manufacture. Ninety days from planting it accumulated high dry matter as indicated by 1.089 specific gravity. It continues to increase to 1.102 specific gravity over a period of 120 days.     

AC Peregrine Red: A High-yielding Red-skinned Fresh Market Cultivar

AC Peregrine Red is a maincrop cultivar that produces very uniform attractive tubers with a deep red skin color. Marketable yields and skin color retention in storage are superior to Norland in Canadian and some U.S.A. locations. The cultivar provides the fresh market industry with a high-yielding red-skinned potato, with good storage capacity and resistance to fusarium dry rot.     

Winema: An Early Maturing, Red- Skinned Cultivar for Fresh Market

Winema, an early maturing, red-skinned cultivar for fresh market use, was jointly released in 2000 by the Agricultural Experiment Stations of Oregon, North Dakota, California, Idaho, and Washington. Winema was evaluated in irrigated trials in Oregon and California from 1990 to 2000 and in the Western Regional Trial in 1995,1997, and 1998. Winema has produced lower total yields than Dark Red Norland and Red LaSoda at most locations, but similar or higher marketable yields and significantly fewer culls. In 20 location-years of replicated Oregon and California trials, Winema produced 108% and 99% of marketable yields of tubers under 280 g compared with Red LaSoda and Dark Red Norland, respectively. Similarly, in 23 location-years of The Western Regional Trial in 6 western states, Winema produced 109% and 92% of marketable yields of tubers under 280 g compared with Red LaSoda and Dark Red Norland, respectively. Winema tubers are smooth-skinned with shallow eyes. Winema’s bright red color does not fade appreciably in storage. Winema is susceptible to potato virus Y (PVY). Foliar symptoms of PVY are difficult to detect visually.     

Mazama: An Early Maturing, Bright Red-Skinned Cultivar For Fresh Market

Mazama, an early maturing red-skinned cultivar for fresh market use, was jointly released in 2000 by the Agricultural Experiment Stations of Oregon, North Dakota, California, Idaho, and Washington. Mazama was tested in irrigated trials in Oregon from 1990 to 2000 and in the Western Regional Trial in 1994, 1995, and 1997. Mazama produces lower total yields than Dark Red Norland and Red LaSoda, but similar marketable yields with a high percentage of small, high-value tubers and significantly fewer culls. In 22 location-years of replicated Oregon and California trials, Mazama produced 40% and 26% higher marketable yields of U.S. #1s under 280 g than Red LaSoda and Dark Red Norland, respectively. In three years of replicated trials in six western states, Mazama produced 115% and 102% of marketable yields of U.S. #1s under 280 g compared with Red LaSoda and Dark Red Norland, respectively. Mazama tubers are smooth skinned and shallow eyed. Mazama’s bright red color does not fade in storage. Mazama is less susceptible to potato virus Y than Dark Red Norland or Red LaSoda.     

Modoc: A potato variety with bright red skin and early maturity for fresh market

Modoc is an early maturing, red-skinned, whitefleshed potato cultivar for fresh market use. The Agricultural Experiment Stations of Oregon, North Dakota, California, Idaho, and Washington jointly released Modoc in 2003. Modoc was derived from a 1989 cross of ND1196-2R and ND2225-1R performed at North Dakota State University. Modoc retains bright skin color in storage and is suited for marketing directly from the field or storage. It produces slightly lower total yield than Red LaSoda or Dark Red Norland, but higher marketable yield and more desirable tuber size and shape. Modoc tubers seldom exhibit growth cracks, secondary growth, hollow heart or other external or internal defects. Dry matter content of Modoc tubers is similar to Dark Red Norland and Red LaSoda (18.9% compared to 18.8% and 17.7%, respectively). Culinary quality of Modoc was rated equal to Dark Red Norland and Red LaSoda for boiling and microwaving preparation methods. Modoc tubers are similar to standard varieties in sugar, vitamin C, and glycoalkaloid (4.5 mg/100 g) concentration. Modoc foliage clearly expresses PVY symptoms and has not demonstrated high susceptibility to viral or fungal diseases during a decade of seed production and evaluation.     

Dakota Jewel: An attractive, new, bright red-skinned, fresh market potato cultivar with improved storage characteristics

‘Dakota Jewel’ is a medium- to late-maturing potato (Solanum tuberosum L.) cultivar; however, tuber maturity is early. Tubers are smooth, round to oblong in shape, with bright red skin and white flesh. Dakota Jewel is suitable for the fresh tablestock market, both directly from the field and following storage. Yield potential is medium, with total yield, U.S. No. 1s and percentage U.S. No. 1s of Dakota Jewel equal to those of Red Norland; size distribution is similar. Dakota Jewel sizes early, retains its color in storage, and has strong dormancy. It is susceptible to hollow heart. A mean specific gravity of 1.077 across non-irrigated and irrigated sites in North Dakota is much higher than Red Norland and Red Pontiac, standard red tablestock cultivars. Sensory evaluation scores of baked, boiled, and microwaved tubers are similar to Red Norland and Red Pontiac. Dakota Jewel was released by the North Dakota Agricultural Experiment Station on 26 March 2004.     

The Influence of Plant Growth Regulators and Inflorescence Removal on Plant Growth,Yield, and Skin Color of Red LaSoda Tubers

Foliar applications of the synthetic auxin compound 2,4-dichlorophenoxyacetic acid (2,4-D) have been used to enhance skin color of red potato cultivars for many years. Relatively, little is known about the mode of action of this compound, but it has been proposed that 2,4-D stimulates ethylene production and enhances the activity of enzymes involved in anthocyanin biosynthesis. The objective of this study was to compare several other plant growth regulators to 2,4-D for their effect on plant growth, tuber yield, and skin color of the light red-skinned cultivar “Red Lasoda.” Trials were conducted in 2010 and 2011 to evaluate the effects of foliar applications of the ethylene-stimulating growth regulator ethephon, the ethylene-inhibitor 1-methylcyclopropene (1-MCP), and 2,4-D. Manual inflorescence removal was also included as a treatment to determine the influence of anthocyanin sink competition between tubers and flowers on tuber skin color. Ethephon application caused floral abscission in treated plants and reduced plant height compared to other treatments and the non-treated control. While 2,4-D caused foliar injury and ethephon slightly increased the yield of <56 g tubers, neither growth regulator affected total and marketable yield. Both ethephon and 2,4-D increased tuber skin color at harvest compared to the non-treated control. In contrast, 1-MCP and inflorescence removal had no effect on yield, tuber size, and skin color. The results indicate that ethephon and 2,4-D foliar applications have similar effects on skin color and appearance, supporting the hypothesis that 2,4-D works by stimulating ethylene production within the plant.     

Nordonna: A red-skinned potato cultivar with wide adaptability

NorDonna is a mid-season, red-skinned, white-fleshed cultivar that yields a large percentage of U.S. No. 1 tubers in diverse growing areas under both dryland and irrigated conditions. It tends to have a darker red skin and a lower incidence of hollow heart when compared to other red cultivars. Intended for tablestock use, NorDonna has baking, boiling, and microwaving properties comparable to Red Pontiac or Red Norland. The North Dakota Agricultural Experiment Station released NorDonna on April 28, 1995.     

Investigations into the mode of resistance of potato tubers toFusarium roseum ‘Sambucinum’

In a histological study comparing tuber resistance of potato clone B7200-33 and susceptible variety “Russet Burbank” toFusarium roseum ‘Sambucinum’, the formation of suberin and wound periderm was found to be an important resistance mechanism. In B7200-33 tubers a continuous suberin layer was formed whereas in ‘Russet Burbank’ tubers the suberin was formed in clumps so that the pathogen easily could invade the tissue between the clumps but not through a continuous layer. Wound periderm also was formed at a more rapid rate in B7200-33 than in ‘Russet Burbank’ tubers thereby “walling off” the pathogen and reducing decay.     

Populations of aphids on named varieties of Irish potatoes

Populations of the green peach aphid,Myzus persicae (Sulzer), and the potato aphid,Macrosiphum euphorbiae (Thomas), were observed on 27 named varieties of Irish potatoes in the Yakima Valley of Washington intermittently from 1947 through 1968. The Epicure, Great Scot, and B5141-6 varieties produced relatively fewer green peach aphids than other varieties tested; Bliss Triumph and Red Pontiac produced relatively fewer potato aphids. Except for Doebay Red, the red-skinned varieties, Bliss Triumph, Red McLure, Norland, and Earnly Rose, were extremely to moderately productive of the green peach aphid. No correlation was apparent between abundance of aphids and the specific gravity or yield of tubers.     

Assessment of PCR-based simple sequence repeats to fingerprint North American potato cultivars

Seven primer pairs flanking di- and tri-nucleotide repeat sequences, identified from previously sequenced regions of the potato genome, were examined for their potential use in DNA-fingerprinting of thirty-nineSolanum tuberosum subsp. tuberosum cultivars (released between 1861 and 1988) and one diploidS. phureja breeding line. Of the simple sequence repeats (SSRs), the primers for six SSRs amplified DNA sequences within the potato genome between cultivars for a total of 14 bands. The polymerase chain reaction (PCR)based amplification products generated from each primer pair consisted of 1 to 2 bands per cultivar but band variation among cultivars demonstrated up to 4 bands per SSR. A similarity matrix generated from five SSRs was able to distinguish 24 of the 40 cultivars. However, when the potato cultivars were grouped by tuber type (round white-skinned, long white-skinned, russetskinned, red-skinned, and yellow flesh) only five pairs of cultivars remained indistinguishable: Atlantic/Katahdin, Belchip/Wauseon, Red LaSoda/Bliss Triumph, Red Pontiac/Norland, and Burbank/Spunta. Although SSRs did not generate unique fingerprints for all of the North American genotypes examined, the potential to discriminate most cultivars should increase as additional SSRs are identified in potato.     

Drip as Alternative Irrigation Method for Potato in Florida Sandy Soils

Seepage irrigation is the most common irrigation system for potato production in Florida, which relies on control of the water table to irrigate the crop. A 2-year trial was established to evaluate the feasibility of drip irrigation as an alternative to seepage for potato production. The performance of ‘Atlantic’, ‘Fabula’, and ‘Red LaSoda’ varieties were evaluated by comparing two drip tape installation depths, surface (SUR) and subsurface (SUB) with seepage (SEP). The overall potato total yield was 25.3; 19.2 and 29.9 Mg ha^?1 for SUR, SUB and SEP, respectively. The SUR and SEP treatments yielded similarly for ‘Fabula’ in both years and ‘Atlantic’ in 2011. The ‘Red LaSoda’ consistently obtained lower yields under both drip treatments compared to SEP. Conversely, drip irrigation promoted significant reduction of the incidence of tuber physiological disorders such as brown center, hollow heart, and internal heat necrosis.     

Marcy: A chipping variety with resistance to common scab and the golden nematode

‘Marcy’ is a white-skinned, white-fleshed potato cultivar notable for its high yield, good chip color, and resistance to common scab and race Ro1 of the golden cyst nematode. It was selected from a cross made at Cornell University in 1990 between ‘Atlantic’ and Q155-3. Full-season marketable yields of Marcy have averaged 15% to 20% greater than Atlantic in 83 trials across New York, Maine, and Pennsylvania. Specific gravity of Marcy has averaged 0.008 less than Atlantic. Chip color out of 7 C storage in New York has been similar to ‘Pike’, but not as light as ‘Snowden’. Marcy tubers have an attractive oval shape, shallow eyes, and highly textured skin. Marcy was jointly released by the New York and Pennsylvania Agricultural Experiment Stations in 2002.     

Skin set evaluation by skin shear measurements

Skin set of tubers, an indication of maturity, is a major reason for desiccating potato vines (Solanum tuberosum L.). A hand-held torque meter was evaluated for measuring tuber skin resistence to shearing as a measure of skin set. To demonstrate practical use of the torque meter to growers, shear resistance must be related to tuber skinning. ‘Atlantic’ and ‘Snowden’ potato tubers were individually measured for skin shear resistance followed by skinning. A linear relationship between skin shear resistance and tuber skinning was observed. The regression equations were Torque (mN*m) = 354 - (1.4 * Percent Skinning) for Atlantic in 1995 and Torque (mN*m) = 404 - (2.2 * Percent Skinning) for Snowden in 1996. The objective measuring of shear resistance was directly related to the more subjective measuring of tuber skinning with an R-square of 0.83. In 1995, harvested Atlantic tubers from desiccated plants were measured for skinning and resistance to torque. Skinning decreased and torque resistance increased during the 3-wk period after the initial desiccation treatment. However, skinning remained unacceptable at one and two weeks after desiccation regardless of treatment. Three weeks after desiccation, tubers from diquat-treated plots showed acceptable skin set levels and a torque resistance over 325 mN*m, which the model indicated would give acceptable skin set. Unacceptable skinning and a low torque resistance, less than 310 mN*m, remained a problem with vine flailing. Data indicated that resistance to torque exerted by the torque meter was an accurate measurement of skin set for harvested tubers. However, model regressions for the two round-white chipping cultivars, Atlantic and Snowden, differed. The torque meter can be used in the field or office. A major difficulty was maintaining a constant pressure on the tuber skin while applying the torque.     

Bannock russet: A dual-purpose, russet potato cultivar with high U. S. No. 1 yield and multiple disease resistances

Bannock Russet, a late-maturing, long russet potato cultivar, was released in 1999 by the USDA-ARS and the experiment stations of Idaho, Oregon, and Washington. It is suitable for processing into french fries and other frozen products. Its attractive russeted skin and excellent culinary qualities also make it suitable for fresh market. Bannock Russet, in comparisons with Russet Burbank, has consistently produced greater U.S. No. 1 yields in trials conducted throughout southern Idaho. In other western trial sites, total yields of Bannock Russet have been comparable to or smaller than that of Russet Burbank, but its percentage of undersize and cull potatoes is consistently less. Bannock Russet is resistant to potato virus Y (PVY), Verticillium wilt, common scab, and leafroll net necrosis. It also has moderate resistance to early blight (foliar and tuber) andErwinia soft rot. With respect to other potato diseases/disorders, Bannock Russet’s level of susceptibility is similar to that of Russet Burbank; the exception being shatter bruise, with Bannock Russet displaying a greater susceptibility. Cultural management guidelines have been developed to minimize shatter bruise in Bannock Russet. Bannock Russet’s multiple disease resistances coupled with its low nitrogen requirement, make it a low-input cultivar that could significantly reduce growers’ production costs.     

Butte: A long Russet potato variety with excellent dehydrating quality

‘BUTTE’, a new long russet potato variety, was released by the Agricultural Research Service, U. S. Department of Agriculture and the Idaho, Oregon, and Washington Agricultural Experiment Stations in April, 1977. Its tubers are similar to those of ‘Russet Burbank’ but BUTTE offers several advantages to growers and processors. BUTTE has averaged 7% more total yield and 25% more U.S. No. 1’s than Russet Burbank over 51 location-years of testing across southern Idaho, eastern Oregon, and in the Columbia Basin. Its specific gravity in these trials averaged .004 higher than that of Russet Burbank. Dehydrating quality of BUTTE is superior to that of Russet Burbank and the product has longer shelf life. BUTTE french fries well although it accumulates slightly more sugars in storage than does Russet Burbank. Its vitamin C content has averaged 58% higher and protein content 20% higher than that of Russet Burbank. BUTTE is hypersensitive to virus X and resistant to net necrosis. Other disease reactions are similar to those of Russet Burbank.     

南方根结线虫侵染对不同砧木嫁接冬瓜生长的影响

为了明确南方根结线虫对不同南瓜砧木嫁接冬瓜苗生长发育的影响,以期为冬瓜生产筛选抗根结线虫砧木品种,促进产业可持续发展。本文采用人工接种南方根结线虫,研究比较了‘海砧1号’、‘海砧2号’和‘银龙黄籽’3种南瓜砧木的冬瓜嫁接苗及冬瓜自根苗的抗性水平及植株生物量的差异。结果表明：不同南瓜砧木冬瓜嫁接苗和自根苗的病情指数、根结指数、卵粒指数和繁殖指数均随着生育期延长而不断升高,抗性水平发生不同程度变化;以‘海砧2号’为砧木的嫁接苗在全生育期均表现为抗病,以‘海砧1号’和‘银龙黄籽’为砧木的嫁接苗表现为高感,‘清远黑皮冬瓜’自根苗表现为感病。在茎叶鲜重和单果鲜重方面,生长中后期以‘海砧2号’为砧木的嫁接苗显著高于以‘海砧1号’和‘银龙黄籽’为砧木的嫁接苗以及‘清远黑皮冬瓜’自根苗,但与未接种的‘清远黑皮冬瓜’自根苗无显著差异。研究结果证实,南方根结线虫明显抑制了感病砧木冬瓜嫁接苗的生长和产量,对抗病砧木嫁接苗无明显影响。