Chip color of the developing potato tuber

Chip color was unacceptable from tubers of Kennebec in an immature condition soon after the tubers were set. Dark colored chips were also obtained from tubers harvested late in the season when soil temperatures were 50 F or less. Two high quality experimental varieties, F5889 in particular, gave excellent chip color regardless of tuber maturity all season and until soil temperatures in fall declined to 40 F. The data indicate that acceptable chip color may be obtained at most stages of tuber development in varieties of high chipping quality. Therefore when selecting seedlings from hybrid plant populations, chip color determined from selections made soon after tuber initiation could be useful. In a supplementary study no marked variations in chip color were obtained from tubers located different distances from the mother plant.     

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.     

Ac novachip: a new potato cultivar with excellent chip quality after long storage and reconditioning

AC Novachip is a smooth, white-skinned potato cultivar with oval to oblong tubers and a maturity similar to Kennebec. It has excellent chip quality, especially after long storage and reconditioning. The boil and bake quality is similar to Kennebec; the specific gravity is higher than Kennebec but lower than Atlantic. AC Novachip has moderate resistance to common scab and PVY.     

Lamoka,a Variety with Excellent Chip Color Out of Cold Storage and Resistance to the Golden Cyst Nematode

Lamoka is a white-skinned, white-fleshed potato variety notable for excellent chip color from cold storage, good yield and specific gravity, and resistance to both common scab and race Ro1 of the golden cyst nematode (Globodera rostochiensis). It was selected from a cross made at Cornell University in 1998 between NY120 and NY115. The tubers are round-oblong and slightly flattened, with shallow eyes and relatively smooth skin. Chip color out of cold storage is better than ‘Snowden’. Marketable yield averaged 90% of Snowden across 95 trials in New York, Pennsylvania and Maine, while specific gravity averaged 0.003 less than Snowden. Lamoka was released by the New York Agricultural Experiment Station in 2011.     

Computerized video image analysis to quantify color of potato chips

Color analysis is a critical quality evaluation procedure in the potato processing industry. This research sought to determine whether potato chip color could be quantified by video image analysis. Russet Burbank and Shepody potatoes, stored at 8 and 5 C, were processed into 8 mm thick chips, which were fried for three time periods. Chip color was characterised by mean gray level values. Changes in video equipment operation and sample presentation were investigated to establish the most reproducible conditions for chip color measurements. The use of image analysis software to analyze mean gray level values from specific regions of the chip was demonstrated. Differences in chip color from potatoes stored at the two temperatures could be distinguished by mean gray level values. For potatoes that had been stored at 5 C, different chip frying times were distinguished on the basis of mean gray level. Chips of 1 mm thickness were prepared from 13 selections and 2 cultivars and color measured by mean gray level, Lvalue (Hunterlab D25L-2 colorimeter) and by Agtron value (Agtron M31A color meter, green mode). Good correlation was found between color assessed by mean gray level and color measured by the Agtron and Hunterlab. A repeatability study showed that image analysis color was not as repeatable as color measured by the two other techniques. Nevertheless, video image analysis appears to have potential as an objective assessor of chip color, and through software development, has specific advantages over other color assessment techniques.     

AC Maple Gold: A High-yielding Yellow-fleshed French Fry Cultivar

AC Maple Gold is a high-yielding oval/oblong, yellow-fleshed potato with an attractive appearance for the fresh market coupled with excellent french fry quality. The cultivar can be harvested early for french fry processing, but also maintains excellent fry quality during long-term storage. AC Maple Gold produces french fries with a uniform deep yellow color.     

Influence of potato composition on chip color quality

Potato constituents were monitored to evaluate their contribution to potato chip color. Five chipping potato varieties: Snowden, AC Ptarmigan, FL 1625, FL 1815 and ND2471-8 were evaluated. Ascorbic acid, sugars, phenolic acids, and amino acids were determined and quantified by High Performance Liquid Chromatography (HPLC) and the color of potato chips was measured by both CIELab Hunter-ColorQuest and Agtron instruments. Composition and chip color varied among the different varieties. AC Ptarmigan and ND2471-8 produced the darkest chip color (on average L*= 49.0, chroma=19.5, and hue angle= 62.9) compared with FL 1815 (L*= 58.4, chroma= 28.3 and hue angle= 75.7). Reducing sugar concentration did not completely explain or predict color quality when it was present in low concentrations (ca. < 60 mg/100g). Other reactants present in the potato slices played an important role in the final color quality of potato chips. Multiple correlation analysis showed negative association of ascorbic acid (r= -0.7), fructose (r= -0.7), a chlorogenic acid isomer (r= -0.7), glucose (r= -0.7) and glutamine (r= -0.5) with potato chip color. Sucrose, chlorogenic acid and asparagine were poor estimators of chip color quality.     

AC Stampede Russet: A high-yielding oblong russet cultivar for the french fry and fresh market industries

AC Stampede Russet has a maincrop maturity, and the tubers reach maximum size in western Canada in early to mid-September. The tubers are attractive with russet skin, shallow eyes, an oblong shape, and are very uniform in size. The cultivar is suitable for french fry or fresh market (count carton) production. It appears to perform best under irrigated conditions. The cultivar provides the industry with a russet-skinned, dual purpose russet cultivar with high yield, low defect levels, excellent fresh market appeal, and good storage quality for both the french fry and fresh market industries.     

Effect of infection byRhizoctonia solani on the quality of tubers for processing

The effect ofRhizoctonia solani infection on the yield and quality of tubers destined for processing was evaluated in a 10 × 2 factorial experiment. Inoculation of 10 cultivars withR. solani significantly decreased total and marketable yields and significantly increased the number of malformed and fissured tubers as well as the number of tubers with black scurf. Specific gravity was significantly decreased in 3 of the 4 years. Chip color at harvest was adversely affected in 2 of the 4 years and over the 4 years combined; whereas chip color three months after harvest was adversely affected in all 4 years.     

Monticello: A mid-season variety with good tuber appearance and chipping potential from mid-to long-term storage

Monticello (NY102), a new medium-maturing, roundwhite chipping variety was released in 2003 by the University of Maine and Cornell University. It is primarily intended for use in the chipping industry, especially from mid-to long-term storage. Its ability to chip from relatively long-term storage, low storage weight loss, and relatively long tuber dormancy should be particularly valuable. Tubers have shown a good ability to recondition and regain good chip color after periods of stress in storage. Monticello’s specific gravity typically averages only a few points lower than Atlantic, a variety that is widely used for out-of-field chipping in the eastern U.S. Chip color of Monticello has been very good from short-, mid-, and long-term storage. It has been grown successfully in commercial-scale tests in Maine since 1999 with combined seed and chipping production of more than 37 and 60 ha during 2001 and 2002, respectively. Research and commercial-scale trials in Maine have generally produced favorable yield and quality results relative to other storage chippers like Snowden. The tubers are bright and attractive with relatively few external defects. Tuber size tends to be fairly small and is ideal for chipping. Sensory panel tests have also shown that Monticello is good for boiling and baking. Although ideally suited for chipping, the fresh market may serve as a secondary market for this variety because of its typically good external appearance and cooking quality scores. Monticello has moderate to good common scab resistance and is resistant to golden nematode. It is moderately susceptible to blackspot bruise, powdery scab, and typical foliar diseases of potato. Although tubers can develop hollow heart and internal heat necrosis, Monticello is typically much less susceptible than Atlantic.     

Ac chaleur: a new early-maturing cultivar with excellent table quality

AC Chaleur is adapted as a second early cultivar in Eastern Canada. It has smooth, bright round-oval tubers with excellent table quality. When harvested at 70-80 days from planting, AC Chaleur tends to outyield Superior. This yield advantage decreases at later harvest times. AC Chaleur has resistance to PVYand moderate resistance to common scab.     

利用Affymetrix芯片分析DON诱导抗赤霉病小麦品种望水白的基因表达谱

中国小麦地方品种望水白不但高抗赤霉病,而且其籽粒中DON(脱氧雪腐镰刀菌烯醇,被认为是赤霉病的致病因子)含量也低.为了研究望水白低DON含量的分子机制,利用Affymetrix小麦基因芯片对望水白受DON诱导调控的基因进行高通量的检测,以DON诱导后12 h和24 h混合样品作为处理组,水处理做为对照.总共检测到差异表达的基因1 114个,其中上调表达的基因有949个,下调基因165个.在上调表达基因中,推断有功能的基因涉及转录因子、信号蛋白、着丝粒蛋白以及与病程相关的基因,如:腺苷三磷酸结合盒转运蛋白,谷胱甘酞转移酶、细胞色素P450酶、苯丙氨酸解氨酶、葡萄糖基转移酶以及抗病蛋白等.对上调表达中的部分基因进行RT-PCR分析,证实它们都受DON诱导上调表达,与芯片检测结果吻合.     

A portable monitor for the rapid assessment of processing quality of stored potato tubers

The present study assessed a commercially available, enzymatically based blood glucose monitor for the rapid determination of processing quality of tuber samples taken directly from storage. This monitor is based on reflectance photometry of a disposable test strip for a chromogen produced during the oxidation of glucose. The influence of storage conditions, harvest location, cultivar, reconditioning effects and the monitoring environment were examined for their effects on glucose levels and chip color. Glucose concentrations were determined by blood glucose monitor, high performance liquid chromatography (HPLC) or YSI biochemical analyzer. Crude tuber extracts did not adversely affect the determination of glucose by the blood glucose monitor and there was no evidence of any interaction between glucose concentration and extract in terms of test strip color development. The test strips demonstrated stable color retention for over an hour although values remained slightly higher after the initial potato extract test. Reaction of test strips to glucose was sensitive to initial temperature of the tuber extract with greatest accuracy exhibited in the 15–22 C range. Chip color was inversely correlated with tuber glucose content regardless of detection method, cultivar, growing site or storage temperature. The highly portable glucose monitor provided a rapid, accurate and quantitative profile of chip processing quality.     

Denali: A high dry matter potato with wide adaptation

Denali is a smooth, white-skinned potato bred and selected for high dry matter content early in tuber development at the Matanuska Research Farm. Its flavor is distinctive and pleasant as a baked potato. Chip quality has been excellent directly following harvest or from warm storage. In Michigan trials, Denali consistently has had the highest specific gravity and has been one of the highest yielders of approximately 20 varieties tested each year. Denali’s foliage has shown frost tolerance and heat resistance in tests conducted in Nebraska.     

Influence of potato specific gravity on yield and oil content of chips

Tubers from bulk samples of Norchip potatoes were separated into specific gravity groups by weighing each tuber in air and then in water. Forty-nine chipping samples were assembled according to specific gravity from the segregated tubers (1.060 to 1.110 specific gravity). Chip yield increased and chip oil content decreased linearly through a specific gravity of 1.110. The contribution of specific gravity to chip yield was demonstrated by expressing chip yeild on a zero percent oil basis. For all lots of Norchips tested, the specific gravity distribution was similar, and all standard deviations (s) were the same (0.0064). Using s, a table of tolerances was compiled for estimation of the appropriate sample size for routine specific gravity determinations.

     

Economic Impacts of Zebra Chip in Idaho,Oregon, and Washington

Zebra Chip disease vectored by the potato psyllid Bactericera cockerelli (?ulc) was first reported in Idaho and the Columbia Basin of Oregon and Washington in 2011. Since then growers have incurred significant costs for managing the disease. Thus, we conducted an expert opinion survey to estimate expenditure on insecticides dedicated to controlling potato psyllids in the largest potato producing regions of Idaho, Oregon, and Washington. Results highlight a total of about 9 million US dollars spent on active ingredients targeted at psyllid control. When application costs are added to the cost of insecticides, expenditures total about 11 million US dollars.     

Identification and Selection for Tuber Calcium,Internal Quality and Pitted Scab in Segregating ‘Atlantic’ x ‘Superior’ Reciprocal Tetraploid Populations

Developing chipping cultivars with improved tuber quality and disease resistance is a major interest for breeders and the potato industry. A popular chipping cultivar ‘Atlantic’, is desired for its high yield and gravity. However, this cultivar suffers from poor internal tuber quality and high scab susceptibility. On the contrary, cultivar ‘Superior’ is known to have excellent tuber internal quality and moderately scab resistance. In addition, this cultivar is known to have high tuber calcium as compared to ‘Atlantic’. The present study intended to generate populations that can be suitable for the genetic study of tuber calcium, internal quality, common scab, and other commercially important traits such as yield, specific gravity and chip quality at the tetraploid level. Two populations obtained by reciprocally crossing the cultivars ‘Atlantic’ and ‘Superior’ were evaluated during 2009 to 2012 at Hancock, Wisconsin. Significant genotype effects and moderately low to high broad-sense heritabilities were identified for all traits evaluated indicating that the observed phenotypic variation has an important genetic component. In addition, the parents differed significantly for all traits across trials, and most genotypes performed in between the two parents but some genotypes were more extreme than the parents. Furthermore, evidence of reciprocal effects was found for some traits. In addition to learning about the genetics of these important traits we were able to identify some genotypes that combined the commercially desired traits of the two cultivars.     

Dakchip: A white-skinned chipping cultivar

North Dakota State University announces the name of a new potato to be called Dakchip. Dakchip is a medium maturing cultivar with chip quality quite comparable to Norchip but better than Kennebec. This new cultivar has round to oblong white skinned tubers and has an excellent plant type and growth. Dakchip is comparable to Kennebec in yield but higher than Norchip. Dakchip has moderate resistance to late blight but is susceptible to most potato viruses and some races of scab.     

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.     

A procedure to correlate color measuring systems using potato chip samples

Measurement of potato chip color is extremely important to the potato processing industry. A procedure is described whereby finished chip samples were utilized for correlation of one spectrophotometric chip color measurement system with another. Calibration, standardization, sample preparation, randomization and prediction equation development procedures are described.