Yield and relationships among tuber size,sucrose and chip color in six potato cultivars on various harvest dates

Cultivars were harvested biweekly for yield, weekly for sucrose determinations, and stored for chipping. At the last harvest Crystal was highest in total and marketable yield. Specific gravity was higher in Lemhi, Russet Burbank, and Norchip than in Kennebec, Crystal and Dakchip. Storage tests showed Norchip had superior chipping color to other cultivars. Dakchip had better color after short rather than after long-term storage, while the opposite was true for Kennebec and Russet Burbank. Lemhi and Crystal were marginal in color throughout storage. Sucrose (mg sucrose/g fresh tuber) expressed as a sucrose rating (SR) ranged from 1.2 to 11.9 among the various cultivars and harvest dates. Correlation between SR’s and tuber size within cultivars ranged from ?.91 to ?.97. Variability in sucrose content of immature tubers explained 70% of the variability in chip color among cultivars after storage from four to six months. Sucrose levels may be used to predict relative chipping quality of various cultivars after moderate to long-term storage if measured during early tuber development when differences in sucrose concentration are greatest among cultivars.     

Differences in sugars,chip color,specific gravity and yield of selected potato cultivars grown in michigan

Six cultivars, Atlantic, Eramosa, Kanona, Norchip, Onaway and Saginaw Gold and four selections, MS 700-70, MS 700-83 (Spartan Pearl), MS 716-15 and W-855 (Snowden), were analyzed for sucrose, glucose, chip color, specific gravity and yield at 98 and 138 days in 1988 and 1989, t evaluate their performance to Michigan growing conditions. The average yield of these cultivars at the two harvests for 1988 and 1989 was 46.9 and 54.7 t/ha and 43.1 and 52.3 t/ha, respectively. Eramosa and Onaway were the earliest maturing varieties with low specific gravity, high glucose content and processed into dark colored chips. The glucose and sucrose contents of the remaining eight cultivars at each harvest date were low and produced acceptable chips. The specific gravity of Atlantic, MS 700-70, MS 716-15 and W-855 was in the range of 1.079–1.088 and for Norchip, Kanona and Saginaw Gold the range was 1.071–1.076. The date of harvest, variety and year of production had significant effect (p > 0.01) on yield. The specific gravity, glucose content and chip color were significantly influenced by variety and year of production. The correlation between chip colorvs glucose (r= -0.842, p = 0.000) and harvest datevs yield (r= -0.572, p = 0.000) was also significant.     

Relationship of harvest sucrose content to processing maturity and storage life of potatoes

Potatoes capable of reaching low sucrose levels prior to harvest demonstrate superior processing maturity for chipping directly from intermediate temperature storage (11.7C, 53F). Forty-nine of fifty-three potato clones with a harvest sucrose rating (SR= mg sucrose/g tuber) between 1.0 and 2.8 chipped long term from storage (7.0 to 11.0 months). Eleven of twelve clones with an SR greater than 2.8 accumulated reducing sugars at a rapid rate and showed short term storage potential (0.5 to 5.3 months). A correlation coefficient of -0.845 was obtained by comparing the harvest SR value to the log₁₀ of storage life with all clones sampled over two growing and storage seasons. A standard sucrose rating (SR) procedure is described to rapidly detect annual variation in processing potato maturity to aid in determining proper post-harvest storage and utilization practices.     

Specific gravity,potato chip color and tuber mineral content as affected by soil moisture and harvest dates

In 1966 and 1967 the chipping quality of three potato varieties was studied using three moisture regumes, two nitrogen levels, and three harvest dates. Specific gravity and chip color of potatoes freshly harvested and of those stored 10 days, along with chip color differences between the two periods, were tested. Of the three varieties tested — Anoka, Kennebec, Irish Cobbler — Anoka§ specific gravity was least depressed by soil-moisture stress and its chip color least affected by time of chipping; all tubers, however, chipped darker after being stored. High soil temperatures were associated with low specific gravities and dark chips. In 1966 irrigation tended to lower soil temperature, resulting in lighter chip color for potatoes harvested from irrigated than from nonirrigated plots; also color was lighter at the first than at the later harvests. In 1967, when air temperatures were consistently lower and rainfall nearly adequate, chip color was lighter for potatoes harvester later in the season. Nitrogen levels did not influence chip color. Moisture regimes and varieties influenced mineral content of tubers more consistently for the two years than did harvest dates or nitrogen levels. Specific gravity did not correlate significantly with chip color.     

Production of perennial ryegrass cultivars of different maturity types when grown as pure swards and in certain combinations

A field investigation was carried out over 3 years to determine if there was a synergistic effect on total or seasonal yield when cultivars of perennial ryegrass were grown in combination. The three cultivars used were Stormont Zephyr, Hora and Perma, representing respectively early, medium late and late maturing groups. Each cultivar was grown as a pure stand and also as a 50:50 mixture with each of the other two cultivars. Each of these swards was maintained under two rates of nitrogen fertilization (300 and 600 kg per ha per annum) and under two harvesting treatments (4 and 8 harvests per annum). Mixture yield did not exceed significantly the pure sward yieid of the highest yielding component. Occasional yield improvements were detected for the mixtures averaged as a group over monocultures averaged as a group. There was a tendency, especially under frequent cutting, for the yield response to nitrogen to be greater from mixed than from pure swards.     

Introgression of cold (4 C) chipping from 2x (2 endosperm balance number) potato species into 4x(4EBN) cultivated potato using sexual polyploidization

Cold-chipping cultivars could reduce microbial spoilage and chemical use due to cold storage of chipping potatoes. Sexual polyploidization breeding schemes that introgress cold chipping from diploid potato species may develop improved cultivars at an accelerated rate. The research objectives were (1) to determine the breeding behavior of cold chipping introgressed from 2× 2 Endosperm Balance Number (EBN) potato species into 4×(4EBN) progeny using sexual polyploidization, and (2) to determine if differences exist between 2n gametes and n tetrasomic gametes for transmission of cold chipping. Experimental families of 4×(4EBN) progeny were synthesized using sexual polyploidization (2× × 4× and 4× × 2×) and 4× × 4× matings using cold-chippingS. phureja and cultivated potato -wild species (C -W) hybrid parents. Control families from 4× × 4× matings using as parents current industry leading germplasm were also made. Progeny were field grown and evaluated for chip color (1 light-10 dark, ≤4.0 is industry acceptable) after 3 and 6 months storage at 4 C. A larger percentage of progeny from experimental families had acceptable chip color compared to control families, likely due to introgression of cold-chipping alleles from diploid potato species. Out of experimental families, the best chip color means, highest phenotypic variance, and greatest percentage of acceptable chipping progeny resulted in 2× × 4× and 4× × 2× matings. The ability of 2n gametes to transmit dominant alleles to high frequencies of 4× progeny may contribute to the superiority of 4× -2× crosses. Breeding schemes that use sexual polyploidization in conjunction with early generation selection should rapidly develop 4× cold-chipping germplasm.     

Tuber yield, storability, and quality of Michigan cultivars in response to nitrogen management and seedpiece spacing

Information is required on nitrogen (N) fertility and seedpiece management for new cultivars and advanced breeding lines. Interactions amongst N fertilizer rate, genotype, and seedpiece spacing are complex, and can affect tuber yield, quality, and storability as well as N fertilizer efficiency. A field study was carried out in 2001 and 2002 at MSU Montcalm Research Farm in central Michigan. Tuber yields and post-harvest quality characteristics were evaluated for five potato genotypes (MSG227-2, MSE192-8Rus, Jacqueline Lee, Liberator, and Snowden) in response to a factorial combination of three N levels (200 kg N ha^-1, 300 kg N ha^-1-, and 400 kg N ha^-1) and two seedpiece spacings, narrow (0.20 m or 0.25 m) and wide (0.33 m or 0.38 m). Narrow seedpiece spacing consistently produced the highest U.S. No. 1 yields in all genotypes tested (37 and 34 t ha^-1, narrow vs wide spacing, respectively). There was a tradeoff between seedpiece spacing and N level in 2001 as tuber yields were enhanced by higher N levels at wide seedpiece spacing, but not at narrow spacing. In 2002, tuber yield was not enhanced, but petiole nitrate-N and tuber-N increased as N fertilization increased. Genotype was the major factor that influenced tuber quality characteristics at harvest and for stored tubers (e.g., specific gravity, internal defects, bruising, chip color rating, sucrose, and glucose). Spacing had minimal effects, whereas higher levels of N slightly reduced specific gravity both years, reduced internal defects in 2001 and enhanced sucrose at harvest in 2002. The cultivars tested demonstrated excellent storage characteristics for different N fertility levels and seedpiece spacing combinations. Overall, the recommended N fertilizer level for moderately long-duration potato cultivars in Michigan (200 kg N ha^-1) and a narrow seedpiece spacing optimized yield and tuber quality performance while conserving N fertilizer.     

Effect of plant population and harvest timing on yield and chipping quality of Atlantic and Norchip potatoes at two Iowa locations

The effect of plant population and harvest timing on potato yield and chipping quality was studied at two Iowa locations during 1986, 1987, and 1988. Evaluations were conducted in eastern Iowa near Muscatine and in western Iowa at Whiting. The cultivars Atlantic and Norchip were planted at in-row spacings of 15, 31, and 46 cm and were harvested approximately 12, 14, and 16 weeks after planting. Delaying harvest until 14 or 16 weeks after planting resulted in greater yields and better specific gravities for both cultivars. At Muscatine, chip color was not significantly affected by harvest date, but at Whiting, each successive harvest produced lighter-colored chips. Greater seed piece populations increased both Atlantic arid Norchip yields. Greater planting populations also caused a small increase in specific gravity. Seed spacing did not significantly affect chip color. In comparison with Norchip, Atlantic produced tubers with higher specific gravities throughout the season and greater total yields on the final harvest date. Atlantic did, however, show susceptibility to hollow heart. The incidence of hollow heart was reduced by close seed spacing.     

TerraRossa: A Mid-Season Specialty Potato with Red Flesh and Skin and Resistance to Common Scab and Golden Cyst Nematode

TerraRossa (POR01PG20–12) is a mid-season specialty potato, released by Oregon State University, and is a product of the Northwest Potato Variety (Tri-State) Development Program. This cultivar is unique among commercially available potato cultivars in that plants produce small- to medium-sized smooth, oblong- to long-shaped tubers with red skin and red flesh. Total tuber yields of TerraRossa are similar to Dark Red Norland and less than Red La Soda. Average tuber size (136 g) is less than both of the comparison cultivars, reflecting inherent differences in tuber size distribution. TerraRossa tubers have total antioxidant levels higher than traditional white fresh varieties and comparable to the All Blue purple potato, known for its high antioxidant levels. Sensory evaluations of TerraRossa tubers indicated that it has good culinary attributes following boiling, baking, and microwaving. Potato chips made from TerraRossa tubers retained their unique red color, which represents a novelty in the chipping industry. TerraRossa could be a good candidate for the organic sector due to its tolerance to common scab (Streptomyces scabies) and tuber late blight (Phytophthora infestans) and its resistance to golden cyst nematode (Globodera rostochiensis). Due to its high yields, high chipping quality, good culinary properties, high antioxidant content and disease resistance, TerraRossa is a good candidate for opening new specialty type markets, adding diversity to the marketplace.     

White Pearl—A chipping potato variety with high level of resistance to cold sweetening

White Pearl is a chipping cultivar with high level of resistance to cold sweetening. The cold-chipping capacity of White Pearl is better than the current chipping cultivars, including Atlantic, Snowden and NorValley. White Pearl has low glucose content and good chip color when processed directly after a 7-month storage period at 3.3 to 5.5 C. White Pearl tubers are similar to Snowden with a round oval shape, light netting, shallow eyes, white flesh, small to medium size, uniform shape, and are practically free of external and internal defects. The yield and specific gravity of White Pearl are medium. White Pearl is similar to Snowden in susceptibility to early blight, pink rot and soft rot, but it is slightly more resistant to common scab. White Pearl vines are susceptible to late blight, but can be managed effectively with fungicides. White Pearl is more sensitive to blackspot bruise than Atlantic or Snowden at 7.2 C, but is more resistant at higher temperatures. White Pearl is sensitive to metribuzin (Sencor), but not rimsulfuron (Matrix) or sulfentrazone (Spartan).     

Identification of potato (solarium tuberosum L.) haploid x wild species hybrids with the capacity to cold-chip

Cold sweetening, the accumulation of reducing sugars in potatoes stored at low temperatures, results in dark chips unacceptable to the consumer. Developing potato cultivars that can chip directly from cooler temperatures (i.e., 3 to 4 C) requires the identification and use of new germplasm with cold-chipping resistance. Individuals from 16 haploid x wild species hybrid families were grown at two sites and their harvested tubers stored at 3 C for 15 wk. Following storage, individuals were evaluated for cold-chipping ability by (1) direct chipping, and (2) reconditioning for 2 wk at 18 C prior to chipping. At both sites, approximately 1% of progeny had good chip color (<2.0 rating using the Snack Food Association scale). Germplasm representing haploid x wild species hybrid families was evaluated for cold-chipping ability following storage of tubers at 3 C for 15 wk, and after storage at 18 C for 2 wk. The two cold-chipping clones identified with chip color means <2.0 were AH 66-1 and H 28-6, hybrids derived fromS. raphanifolium accessions 296126 and 310998, respectively.S. raphanifolium PI 296126 was exceptional in that chip color means of its progeny were 2.5 and 2.7 at McLeod (North Dakota) and Crookston (Minnesota), respectively. All clones with chip color means <2.6 involvedS. raphanifolium PIs 296126, 310998, and 458384 in their parentage. Following reconditioning, the number of progeny in the good and medium chipping categories improved from direct chipping with 14.1% of the progeny at McLeod and 3.8% at Crookston in the good chipping category.S. raphanifolium PIs 210048 and 310998 together accounted for 100% and 50% of the clones with chip scores <2.0 at McLeod and Crookston, respectively. Clones ranking high for chip color following direct chipping generally chipped well following reconditioning.     

Effect of planting and harvest dates,location in the hill and tuber size on sugar content of Kennebec potatoes

A study was made with the Kennebec cultivar on the effect of planting and harvest times, location of tubers in the hill and tuber size on fructose, glucose and sucrose in tubers at harvest. The location of tubers in the hill did not affect fructose or glucose and had only a small effect on sucrose found in the tubers. Small tubers were higher in all three sugars than large tubers, and tubers from plants seeded later were higher in glucose and sucrose than tubers from plants seeded early. The early plantings at all harvests outyielded the late plantings. This together with the higher quality (lower sugars) support the recommendation that Kennebec potatoes to be used for processing should be planted early.     

Growth responses,cooking quality determinations,and leaf nutrient concentrations of potatoes as related to exchangeable calcium,magnesium, and potassium in the soil

Field experiments were conducted during 1977 and 1978 to determine the relationship between percent exchangeable Ca, Mg, and K in the soil, and yield, quality, and leaf concentration of 11 elements for several potato cultivars. The highest yields were obtained in soil containing a combination of 5% Mg and 5% K of the cation exchange capacity. All cultivars grew equally well in the high Ca field as in the low Ca field. Potato scab was no problem. Potassium treatment levels had a consistent effect on yield, specific gravity, and chip color. Specific gravity decreased and chip color improved as the K treatment levels increased from 2 to 8% of the CEC. Leaf elemental concentrations showed few consistent effects as a result of the Mg and K soil treatments.     

Genetic components of chip color evaluated after harvest,cold storage and reconditioning

For the consumer, color is the most important factor in judging about the quality of the potato chips. A partial diallel analysis of eight parents with processing attributes was conducted over two years to evaluate the importance and inheritance of chip color stability after potatoes have been stored at cold temperatures. Chipping color evaluation was made soon after harvest, after three months storage at cold temperature (6–7°C), and after reconditioning (22–24°C) from cold temperature storage on progenies and controlled genotypes. Principle component analysis showed merit in the extraction of an “overall chipping ability” component and a “chipping stability” component which explained 75% and 12% of the original variability, respectively. Significant GCA and SCA effects were found for both components and for each of the original variables. The inheritance of overall chipping ability was largely due to GCA effects. Genetic interactions were more important for chipping stability than for overall chipping ability. Chipping stability of the progenies could not be predicted based on the parents’ performance. It is recommended that screening for overall chipping ability be performed before screening for chipping stability in a potato breeding program.     

Changes in juice quality and sugarcane yield with recurrent selection for sucrose

Sugarcane (Saccharum spp. hybrids) breeding programs in Louisiana have made improving sucrose content a top priority because a short growing season limits cane yield. Using a recurrent selection strategy, the cultivars with the highest sucrose content are crossed, and a new generation of cultivars is selected from the progeny. This study was designed to determine how selection primarily for sucrose content has modified physiological characters, and impacted sucrose content and yield. Five cultivars were randomly selected from each of seven generations of recurrent selection in Louisiana and planted in two experiments. The plant and first stubble crops were harvested late in the harvest season from each experiment. Cane yield and juice quality were determined. Cultivars from the last three generations were superior to cultivars from the first three generations for Brix % cane, sucrose % cane, purity, theoretically recoverable sugar (TRS), cane yield and sugar yield. Fiber % cane was not different among the generations. Selection primarily for sucrose has increased Brix % cane from 14% to 16%, sucrose % cane from 12% to 14%, purity from 82.5% to 87.3%, and TRS from 98 to 122 kg Mg⁻¹. A plateau in juice quality and sucrose yield in the last three generations may indicate that: (1) Louisiana's short growing season may restrict sucrose accumulation; (2) the genetic potential for late season juice quality has been reached with currently available germplasm; or (3) the inclusion of lower juice quality Saccharum spontaneum germplasm into the breeding program in order to increase disease tolerance, cold tolerance, and ratooning ability has diluted the effect of recurrent selection for sucrose.     

The influence of glycoalkaloids,chlorogenic acid and sugars on the susceptibility of potato tubers to wireworm

Summary Field experiments with four potato cultivars showed that there were significant differences in susceptibility to attack by wireworm,Agriotes obscurus. The two most susceptible cultivars had the lowest total glycoalkaloid (TGA) contents. Laboratory experiments with wireworms feeding on tuber slices demonstrated that regions characterized by a low sugar and a high glycoalkaloid concentration were avoided as feeding sites. Bio-assays with glycoalkaloids also showed that paper discs treated with a mixture of solanine and chaconine were avoided by wireworms. According to a forward stepwise regression analysis based on data from four cultivars and six regions of the tuber. TGA was the key factor in predicting larval feeding, accounting for 65% of the total variation. Differences in reducing sugar levels (fructose + glucose) explained an additional 13% of the variation. Differences in chlorogenic acid and sucrose levels added very little to the accuracy of the prediction.     

Recurrent selection for sucrose content has altered growth and sugar accumulation in sugarcane

Sucrose content is one of the main factors sugarcane (Saccharum spp. hybrids) breeders use in selecting new cultivars. To determine how growth and sugar content have been altered by six cycles of recurrent selection for sucrose, five cultivars from the first generation (released from 1924 to 1933) were compared with five cultivars from the seventh generation (released from 2003 to 2007). In July of 2006 and 2007, we flagged 20 stalks per plot and marked the top internode that was just beginning to elongate. We then sampled one stalk per plot at weekly to biweekly intervals for 12 weeks. We measured stalk length and internode number, and the length, fresh weight, dry weight, water content, and sugar content of the marked internode. Stalks from the Generation 7 cultivars were taller, and had more internodes than those from Generation 1 cultivars. The marked internodes of Generation 7 and Generation 1 cultivars had similar elongation rates during early development, but elongation ended earlier in Generation 7 cultivars so that internodes of Generation 7 cultivars were shorter when fully elongated than those of Generation 1 cultivars. These shorter internodes had lower fresh weights, but similar dry weights as the longer Generation 1 internodes. Water content also decreased faster in Generation 7 than Generation 1 internodes. Generation 7 internodes had more total sugar and more sucrose throughout development. Generation 7 internodes also maintained a higher sucrose:total sugar ratio until the end of the sampling period. We conclude that recurrent selection for sucrose content in sugarcane has altered the allocation of photosynthate from growth to storage within the internode. This is possibly due to a change in the regulation of sucrose metabolism within the internode.     

两种生长调节剂对大豆叶片昼夜同化物生理代谢及产量的影响

为探究两种不同类型植物生长调节剂对大豆叶片昼夜同化物生理代谢的影响,以两个大豆品种合丰50和垦丰16为试验材料,于始花期叶面喷施烯效唑(S₃₃₀₇)和2-N,N-二乙氨基乙基己酸酯(DTA-6),在鼓粒期的一昼夜内依次选取9∶30、17∶30、21∶30和5∶30(次日)4个时间点,测定功能叶片中蔗糖含量、淀粉含量、淀粉转化率、蔗糖代谢关键酶活性,并于成熟期测产。结果表明:S₃₃₀₇和DTA-6处理均能促进两品种叶片蔗糖和淀粉在白天的积累和夜间的降解,且S₃₃₀₇对两品种叶片蔗糖的调控效果优于DTA-6,DTA-6调控两品种叶片淀粉的作用效果优于S₃₃₀₇。在不同时间点S₃₃₀₇和DTA-6处理均能够提高两品种叶片夜间蔗糖和淀粉转运率。S₃₃₀₇和DTA-6处理能够提高两品种叶片蔗糖合酶和蔗糖磷酸合酶活性,且均在17∶30达最大值;S₃₃₀₇和DTA-6在整个昼夜变化中提高两品种蔗糖转化酶的活性。S₃₃₀₇和DTA-6能够有效调控两品种的单株荚数和单株粒数,提高产量,S₃₃₀₇和DTA-6处理后合丰50产量与对照相比分别增加17.76%和37.67%,垦丰16产量与对照相比分别增加11.34%和32.49%。综上所述,S₃₃₀₇和DTA-6处理均能通过促进叶片昼夜同化物代谢,提高合丰50和垦丰16大豆品种产量。     

The effects of clover variety, cutting interval and nitrogen application on herbage yields, proportions and heights in perennial ryegrass-white clover swards

Six varieties of white clover, each grown with perennial ryegrass, four intervals between cuts and two levels of applied nitrogen in all combinations, were compared in a field experiment during the first 27 months after sowing.
Increasing the interval between harvests from 3 or 4 to 8–12 weeks increased the yield of white clover and generally did not reduce the proportion of clover in total herbage. Increasing the interval between harvests reduced the number of grass tillers but increased grass yield and the size of grass leaves and increased grass height more than clover height; it also increased the proportion of petiole relative to leaflet in the clover. Differences between varieties in response to interval between harvests were small but supported the view that medium large-leaved varieties can with advantage be defoliated rather less frequently than small-leaved ones. The adverse effect of applied N on clover appeared almost equally great with all four intervals between harvests and further research on this topic is suggested. Applied N increased grass height more than clover height and increased the number of grass tillers, the size of grass leaves and grass yield. The medium large-leaved varieties seemed more tolerant of applied N than the smaller varieties.     

The effect of companion perennial ryegrass cultivars on red clover productivity when timing of the first cut is varied

Replicated plots of Hungaropoly red clover were sown on a sterilized area in May 1975 alone (seed rate 11 kg ha^-1) or with one of six cultivars of perennial ryegrass (seed rate 3·5 kg ha^-1) viz. Cropper and S24 (early heading), Barlenna and Hora (medium heading) and Melle and Perma (late heading). In 1976 and 1977 primary growth was cut at one of four dates ranging from mid-May to mid-June and thereafter plots were harvested twice each year.
Varying the time of first cut did not have a significant effect on total dry matter (DM) yield in either year despite differences in means of cutting treatments on annual red clover yields of the order of 6–9%.
In some companion grass treatments total DM yield in 1976 was increased and total red clover yield and percentage red clover contribution were reduced relative to swards sown only with red clover. In 1977 a similar but non-significant trend was found. Swards containing early ryegrasses had higher total herbage DM yields but lower red clover yields and contents than all other swards at the first harvest in both years.
Delay in date of taking the first harvest in 1976 reduced DM digestibility in the first cut and increased it in the second in both years.
It is suggested that by cutting early and increasing the number of harvests from three to four per year, differences in the content of red clover between the first and second cut might be reduced, and it is concluded that more benefit is derived from red clover when medium or late heading ryegrasses are used as companion grasses.