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1.
Nitrogen fertilization, irrigation, and cultivars affect tuber characteristics such as tuber size, specific gravity, and N concentration. Few studies, however, have investigated the interaction of irrigation and N fertilization on the tuber characteristics of potato cultivars, particularly in Atlantic Canada. The objective of this on-farm study, conducted at four sites in each of three years, 1995 to 1997, was to determine the effects of supplemental irrigation and six rates of N fertilization (0-250 kg N ha-1) on the number of tubers per plant, the average fresh tuber weight, tuber N concentration, nitrate (NO3-N) concentration, and specific gravity of the cultivars Shepody and Russet Burbank. Nitrogen fertilization increased the average fresh tuber weight, tuber N and N03-N concentrations, and decreased specific gravity. Effects of increasing N fertilization on tuber characteristics were often more pronounced for Shepody than for Russet Burbank, and for irrigated than for non-irrigated conditions. Shepody had greater average fresh tuber weight and tuber N concentration, lower specific gravity, and fewer tubers per plant than Russet Burbank. Supplemental irrigation increased the average fresh tuber weight and the number of tubers per plant, but it had a limited effect on specific gravity and tuber N and NO3-N concentrations. Tuber NO3-N con centration and specific gravity were strongly related to tuber N concentration, which in turn depended primarily on N fertilization. Incidents of lowest specific gravity and highest NO3-N concentration occurred with a relative yield close to or equal to 1.0. We conclude that the risks of low specific gravity and high tuber NO3-N concentration are greater when fertilization exceeds the N requirements to reach maximum tuber yield.  相似文献   

2.
Nitrogen and water deficiencies are known to affect potato yield, but much less is known of their effect on tuber growth and biomass partitioning. The objective of this on-farm study conducted at two sites in each of three years, 1995 to 1997, was to determine the effects of supplemental irrigation and N fertilization rates on tuber growth and biomass partitioning of the cultivars Shepody and Russet Burbank. The N fertilization rates were 0,100, and 250 kg N ha-1in 1995, and 0, 50,100, and 250 kg N ha?1 in 1996 and 1997. The highest bulking rate observed in our study (7.3 g fresh tubers m-2 °C-1) can be considered near the potential bulking rate in New Brunswick. The water deficit in the absence of supplemental irrigation reduced this potential bulking rate by as much as 40%, but this reduction was much less at five of six sites and negligible at two of six sites. Nitrogen deficiency reduced the bulking rate at two of six sites. This negative effect of N deficiency on bulking rate was greater with irrigation than without irrigation at two of six sites; the tuber bulking rate with irrigation was reduced by as much as 50% with no N applied at one site. Shepody had a greater bulking rate than Russet Burbank. The tuber bulking of Russet Burbank, however, started earlier and lasted longer than that of Shepody. Water and N deficiencies increased biomass partitioning to tubers and large roots. Shepody partitioned a greater proportion of its biomass to large roots and had a greater root biomass than Russet Burbank. Our results demonstrate the ability of potatoes to modify biomass partitioning when grown under water and/or N stresses. As a result of this compensation, the reduction in tuber yield due to limited N and water stresses is minimized.  相似文献   

3.
Plant-based diagnostic methods of nitrogen (N) nutrition such as petiole nitrate (NO3-N) concentration can be used to improve the efficiency of N utilization, and hence decrease the risks of N losses to the environment. Our first objective was to determine the effect of N fertilization and supplemental irrigation on the petiole NO3-N concentration during tuber growth of two potato cultivars, Russet Burbank and Shepody, widely grown for processing in Eastern Canada. Our second objective was to establish the critical petiole NO3-N concentration using the relationship between petiole NO3-N concentration and the N nutrition index (NNI), an index based on the N concentration of shoots and tubers. This on-farm study was conducted at two sites in each of three years, 1995 to 1997. The N fertilization rates ranged from 0 to 250 kg N ha?1 with three rates in 1995, six rates in 1996, and four rates in 1997. The NO3-N concentration of petioles from the most recently mature leaves was measured on three sampling dates in 1995 and four sampling dates in 1996 and 1997. The petiole NO3-N concentration generally decreased with time. At all sites and on all sampling dates, the petiole NO3-N concentration increased with increasing N fertilization and was significantly greater for Shepody than for Russet Burbank. Irrigation had no consistent effect on petiole NO3-N concentration. Petiole NO3-N concentration was related to NNI (0.29<R2<0.62). Critical petiole NO3-N concentrations required to reach a NNI of 1.0, indicating a situation where N is not limiting growth, were greater for Shepody than for Russet Burbank, and they decreased with time. Critical petiole NO3-N concentrations (Y) expressed as a function of the number of days after planting (X) are Y = 4.80 - 0.055X for Russet Burbank and Y = 5.03 - 0.054X for Shepody.  相似文献   

4.
Tuber initiation and development in irrigated and non-irrigated potatoes   总被引:1,自引:0,他引:1  
Tuber initiation and development are processes basic to potato production and are particularly critical in areas with short growing seasons. It is important to know how and to what extent management decisions affect these processes in order to maximize the yield of marketable tubers. A two-year field study, conducted in southcentral Alaska, examined top growth, tuber initiation, and tuber development in eight potato cultivars grown with and without irrigation. Plants of the cultivars Allagash Russet, Bake-King, Green Mountain, Kennebec, Lemhi Russet, Russet Burbank, Shepody, and Superior were harvested weekly throughout the growing season, and top dry weight, numbers of tubers, and individual tuber fresh weights were recorded. Top dry weight was reduced by moisture stress shortly after emergence in 1993, and about one month following emergence in 1994, when early-season soil moisture was greater. The weight of tubers was similarly affected within approximately 5 wk of emergence in 1993 and 6 weeks in 1994. Tuber weight at harvest was increased two-to three-fold by irrigation in all cultivars. The number of tubers each plant set was affected by irrigation in most, but not all, cultivars. Some varieties (Lemhi Russet in 1994, Allagash Russet both years) set more tubers than were maintained through the growing season. Tuber remnants found during sample collection indicated that tuber reabsorption had occurred. Irrigated Green Mountain had more than one tuber initiation period during the season, whereas other varieties such as Shepody maintained a relatively constant number of tubers following initial tuber set. Tuber size distribution at the end of the growing season showed that larger tubers were favored by irrigation.  相似文献   

5.
Russet Burbank and Shepody potatoes of different chemical maturities (i.e. varying sucrose concentrations) at harvest were preconditioned by holding at 15 C for various durations to lower the concentration of reducing sugars to levels acceptable for processing as french fries out of 8 C storage. In chemically immature tubers (i.e. those harvested with a high sucrose), sucrose declined after harvest and stabilized in storage regardless of the preconditioning period. However, there was a temporary small increase in sucrose after harvest in more chemically mature tubers. The concentrations of the reducing sugars glucose and fructose were low at harvest, usually < 1.0 mg g?1, but increased rapidly during the first 30 to 45 d of storage in tubers with more than 2.0 mg g?1 sucrose at harvest. Preconditioning for up to 70 d at 15 C either limited the increase in reducing sugars or lowered them more rapidly during storage than when preconditioned for only 14 d. Fresh weight loss of Russet Burbank and Shepody was greater in physically and chemically immature tubers compared to more mature tubers. Extended preconditioning of Russet Burbank and Shepody resulted in minimal additional weight loss.  相似文献   

6.
Abstract

Plant-based diagnosis is one of the most important methods to determine nitrogen (N) content of crops. Our objective was to establish the relationship between soil-plant analysis development (SPAD) values and N nutrition index (NNI) during the three developmental stages of rice and apply the SPAD meter as diagnostic tools for predicting grain yield response to N fertilization. We determined the SPAD values of four uppermost fully expanded leaves of two rice cultivars at six N fertilization levels at three growth stages and examined the relationship between SPAD values and NNI. The critical N concentration (Nc) was 5.31 W–0.5 in Xiushui63, and 5.38 W–0.49 in Hang43, where W is the total shoot biomass. The correlation between SPAD value and NNI varied with the leaf position, developmental stage, and variety. The lower leaf appeared to be more sensitive to the N level than the upper leaf in the response of biomass, and could be more suitable as a test sample for N status diagnosis, especially in the booting and heading stage. The dependence of grain yield on SPAD values of the fourth fully expanded leaf (L4) was significant at booting stage (R2L4 = 0.82** in 2011, R2L4 = 0.72** in 2012). Ratio of SPAD values of L4 to that in the N-saturated plot (RSPAD) (R2L4 = 0.92** in 2011, R2L4 = 0.77** in 2012) and NNI (R2 = 0.96** in 2011, R2 = 0.86** in 2012) at booting stage demonstrated a closer relationship with grain yield.  相似文献   

7.
8.
Irrigation and nitrogen management are two of the most important factors affecting production efficiency and environmental quality in potato cropping systems. Field studies were conducted in 1990 and 1991 to determine the interactive effects of irrigation amount and N timing on potato yield, quality and nitrate leaching potential. Sprinkler irrigation was applied at approximately 1.0, 1.2 or 1.4 times estimated evapotranspiration (ET) to Russet Burbank potatoes grown on a silt loam soil. Following tuber initiation, a total of 132 kg N/ha was applied through the irrigation system to N treatment subplots using either six weekly 22 kg N/ha applications or 3 biweekly 44 kg N/ha applications. Excessive irrigation reduced root zone and petiole NO3-N concentrations during substantial portions of the tuber bulking period. Biweekly 44 kg N/ha applications in 1991 produced higher and more consistent earlyseason root zone NO3-N concentrations in the 1.2 and 1.4 ET plots than did the weekly 22 kg N/ha applications. Late-season tuber dry weight, total plant dry weight and plant N uptake were not affected by irrigation rate or N timing. However, excessive irrigation reduced U.S. No. 1 yield and yield of tubers >284 g in both 1990 and 1991 and reduced total yield in 1990. Biweekly N applications produced higher U.S. No. 1 yields than weekly N applications at all irrigation levels. Excessive irrigation also reduced NO3-N remaining in the top 60 cm of soil at the end of the growing season. These results show that irrigating at optimal rates and applying split N at two week intervals on a silt loam soil can maximize Russet Burbank yield and quality while minimizing NO3-N losses.  相似文献   

9.
Nitrogen and water are important factors influencing potato production, and crop response to these two factors may vary with cultivars. The yield response of two potato cultivars (Russet Burbank and Shepody) to six rates of N fertilization (0-250 kg N ha-1) with and without supplemental irrigation was studied at four onfarm sites in each of three years, 1995 to 1997, in the upper St-John River Valley of New Brunswick, Canada. On average, irrigation increased total yield from 31.9t ha-1 without irrigation to 38.41 ha-1 with irrigation and marketable yield from 25.61 ha-1 without irrigation to 30.71 ha-1 with irrigation. Potato yields were increased by irrigation at nine out of the 12 sites, and the irrigation response was similar for both cultivars. Nitrogen fertilization significantly increased both total and marketable yields at all sites except one. The yield response to N fertilization was greater with irrigation. The N fertilization rate (Nmax) required to reach maximum total and marketable yield, however, was similar with and without irrigation. A large variation in Nmax was observed among sites. With irrigation Nmax varied between 158 and 233 kgN ha-1 for total yield, and between 151 and 250 kg N ha-1 for marketable yield. There was no interaction between N fertilization and potato cultivar for both total and marketable yields. The two cultivars had similar total yields (35 t ha-1). Shepody, however, had a greater marketable yield (28.9 t ha-1) than Russet Burbank (27.4 t ha-1). Our results indicate that the response to two of the most significant factors of potato production, irrigation and N fertilization, varies greatly with sites and climatic conditions, and that field specific recommendations are required for the optimum management of N and irrigation.  相似文献   

10.
Previous short-term trials (9-week duration) have shown that the fry colour of stored potatoes (Solanum tuberosum L.) can be negatively affected by simultaneous exposure to elevated CO2 plus a trace concentration of ethylene gas. In the present study, trials were conducted during each of two storage seasons (2008–2009 and 2009–2010), to examine the effects of long-term exposure to these two gases during the entire November to June storage season. In each year, 0 or 2 kPa CO2 and 0 or 0.5 μl l−1 ethylene were applied in a factorial design to tubers of four processing cultivars (Russet Burbank, Shepody, Innovator and Dakota Pearl). Processing colour of the tubers was evaluated at the start of each trial and at intervals of 4 weeks thereafter. In the three French fry cultivars (i.e. Russet Burbank, Shepody and Innovator), the fry colour of tubers exposed to CO2 + ethylene together was darker than the controls. In the chipping cultivar Dakota Pearl, the gas treatments had only a small effect on chip colour. Fry colour darkening due to an interaction of CO2 × ethylene × time was significant only in Innovator. Processing colour of all cultivars was darkened by these gases, but the magnitude and timing of the responses varied widely between gases, among cultivars and from the start to the end of the season.  相似文献   

11.
Micropropagation is a tissue culture technique adapted for the rapid multiplication of disease-free seed stocks. Procedures for propagating potatoes in the laboratory and acclimating plantlets in the greenhouse are available, but information on cultural practices for maximizing tuber yield of plantlets when transplanted to the field is lacking. Centennial Russet and Russet Burbank plantlets were transferred from culture jars to three sizes of transplant containers for establishment under greenhouse conditions before transplanting to the field. Length of field growing season was varied by using two transplant dates and two vine kill dates. Survival of field transplanted plantlets was above 95 percent in both 1983 and 1984. Cultural practices significantly affected the tuber yield of plantlets of both cultivars. Total yield and yield of tubers larger than 35 mm in diameter increased with increasing transplant container volume. Transplant container volume had no effect on the yield of tubers less than 35 mm in diameter. Highest total yields and tuber production per plantlet for both Centennial Russet and Russet Burbank were obtained from the longest growing season (early transplant date with late vine kill). Yield of Russet Burbank plantlets increased more in response to a longer growing season than did Centennial Russet.  相似文献   

12.
Fertilizer nitrogen (N) may be managed to increase crop production and profitability while reducing nitrate contamination of groundwater. A two-year field investigation was conducted to evaluate the effects of applied N on tuber yield and quality, dry matter production and N uptake of potato (Solanum tuberosum L. var. Russet Burbank) grown on irrigated sandy soils in Michigan. Nitrogen was applied as ammonium sulfate [(NH4)2SO4] at rates of 0, 56 and 112, kg N ha?1 in a single application at planting or 112 and 168 kg N ha?1 in split applications during the growing season. Total tuber yield generally increased with N applications up to 112 kg N ha?1. Only one of the three experimental sites showed an increase in marketable tuber yield when 112 kg N ha?1 was split evenly between planting and tuber initiation. Tuber specific gravity was not affected by N rate. Nitrogen rates of 112–168 kg N ha?1 maximized dry matter production and plant tissue N concentration at onset of maturity and harvest. Tuber N concentration at harvest ranged from 13–17 g kg?1 at two of the three locations. Values for the third experiment were 10–13 g N kg?1. Whole crop N uptake at onset of senescence ranged from 45 to 225 kg N ha?1 across all locations and treatments. An average of 67 percent of this N was found in tubers at harvest. Nitrogen fertilization exceeded N removal in harvested tubers by more than 50 kg N ha?1 only for the 168 kg N ha?1 treatment. These results indicate that acceptable tuber yield can be obtained with lower N rates than those currently used by most producers, with the potential for reducing net loss of N from the soil.  相似文献   

13.
Previous research suggests that field greening of potato tubers can be minimized by planting seedpieces at an appropriate depth along with sufficient hilling to minimize exposure to sunlight. The appropriate planting depth and hilling practices to minimize field tuber greening have not been determined for newer cultivars. Two separate studies, each conducted for three years, are reported here. The first measured the effect of seedpiece planting depth on the yield, quality, and field greening tuber yield of ‘Russet Burbank’, ‘Frontier Russet’, and ‘Shepody’ potatoes. Seedpieces were handplanted in pre-formed hills at 8, 15, or 23 cm measured from the top of the seedpiece to the top of the hill. Planting at 23 cm resulted in significantly lower total yield compared with the 8- and 15-cm depths for Russet Burbank and Frontier Russet, but planting depth did not affect total yield of Shepody. U.S. No. 1 yield of Russet Burbank was not affected by planting depth, but U.S. No. 1 yield of Frontier Russet was significantly less at the 23-cm depth. For Shepody, the 8-cm depth caused a significant reduction in U.S. No. 1 yield compared with the 15-cm depth. Field greening tuber yield of Russet Burbank was significantly less at the 23-cm planting depth compared to 8 cm. For Frontier Russet and Shepody, planting at 15 or 23 cm resulted in significantly less field tuber greening compared to the 8-cm depth. The second experiment examined the effects of planting depth and hilling practices on yield, quality, and field tuber greening of Russet Burbank and Gem Russet potatoes. Six planting depth and hilling treatment combinations were used. Seedpieces were planted at a depth of either 8 or 15 cm, then hilled to either 15 or 23 cm at emergence or after plants had formed a rosette of leaves approximately 10 cm in diameter (post-emergence hilling). At-emergence hilling treatments had no effect on total or U.S. No. 1 yields of Russet Burbank compared with the 15-cm planting depth, non-hilled control. However, all post-emergence hilling treatments significantly reduced Russet Burbank total and U.S. No. 1 yields. Planting Russet Burbank at 8 cm and hilling to 23 cm at emergence, or planting at 8 or 15 cm and hilling to 23 cm post-emergence reduced field tuber greening of Russet Burbank. The effects of planting depth and hilling on Gem Russet total and U.S. No. 1 yields were less definitive than for Russet Burbank, and no treatments significantly reduced field tuber greening yield compared with the control.  相似文献   

14.
Potato plants of Russet Burbank, Oromonte and Red McClure varieties were studied in the San Luis Valley of Colorado to determine their dry matter and nutrient accumulation. The following observations were made in the 1967 growing season.
  1. Growth patterns for the three varieties were similar, but average growth rate of Oromonte and Red McClure was higher than that of Russet Burbank.
  2. Top growth reached its peak in 61, 55, and 50 days after emergence for Russet Burbank, Oromonte and Red McClure, respectively.
  3. In the 3 weeks before killing forst, tuber growth equalled 50% of maximum tuber dry weight for Russet Burbank and about 61% for Oromonte and Red McClure.
  4. Total N uptake with a yield of 300 cwt per acre was about 127 lb for each variety, assuming a linear relationship between tuber yield and nitrogen uptake. The tubers contained about 71% of the total N uptake.
  5. Total P uptake with a yield of 300 cwt per acre was about 16 1b for each variety, assuming a linear relationship between tuber yield and P uptake. The tubers contained about 83% of total P uptake.
  6. Total K uptake with a yield of 300 cwt per acre was 132, 187, and 147 lb (not significantly different) for Russet Burbank, Oromonte and Red McClure, respectively, assuming a linear relationship between tuber yield and K uptake. The Russet Burbank tubers contained 63% of the total K uptake and Oromonte and Red McClure about 52%.
  7. Tuber dry matter per cent increased during the season until 2 weeks before a killing frost (65 to 69 days after emergence). At harvest, the dry matter approximated 21% for the varieties studied.
  相似文献   

15.
Many potatoes in the Northwest are grown on sandy soils with sprinkler irrigation. The low water holding capacity and restricted rooting often associated with coarse-textured soils create conditions where water stress injury is likely. Temporary water shortage due to irrigation system failure is a hazard on these soils. The Russet Burbank cultivar is often severely injured by such water stress. It is not known how the cultivars Nooksack and Lemhi respond to these conditions. A study was conducted to compare the responses of Russet Burbank, Nooksack, and Lemhi cultivars to interruptions in irrigation during tuber initiation or during bulking, and to gradually increasing water stress from declining water application rates during the last 8 to 10 weeks of the growing season. In most categories evaluated, Russet Burbank was most injured by water stress, especially in percent U.S. No. 1 tubers. Much of the decrease in U.S. No. 1 tubers was due to small size. Nooksack generally was the least affected by water stress while Lemhi was affected slightly more than Nooksack. Both Nooksack and Lemhi withstood periods of water stress and produced satisfactory yields and grades of tubers while Russet Burbank did not produce profitable levels of marketable tubers.  相似文献   

16.
The release of three new potato (Solarium tuberosum L.) cultivars, Bannock Russet, Gem Russet, and Summit Russet, with unique plant growth characteristics, necessitates the development of appropriate N fertilizer recommendations. These three new cultivars, along with the standard cultivar, Russet Burbank, were treated with four N rates (0, 100, 200, and 300 kg N ha?1) using two different application timing procedures (“early,” with two-thirds N applied preplant, and “late,” with one-third applied preplant). Measurements included total and U.S. No. 1 yields, petiole NO3-N concentrations, and net returns derived from economic analysis using a processing-based contract. Each of the four cultivars showed a unique response to N application treatments. Bannock Russet achieved maximum yield and net returns with relatively small amounts of N fertilizer. It also showed no response to N application timing and had moderate NO3-N sufficiency concentrations early in the season, that decreased markedly late in the season. Gem Russet N requirement for maximum yield was similar to that of Russet Burbank, but required a higher amount of N for maximum net returns. Gem Russet also showed no response to application timing and had NO3-N sufficiency concentrations similar to or slightly higher than those of Russet Burbank. Summit Russet showed a strong trend for improved N use-efficiency when most of the N was applied early. On the other hand, analysis of net returns revealed a trend for greater profitability for Summit Russet when the majority of N was applied during tuber bulking. Petiole NO3-N sufficiency concentrations for Summit Russet were generally higher than those for the other three cultivars. In comparison with some earlier studies with Russet Burbank, this research suggested lower optimal N rates and petiole NO3-N sufficiency concentrations.  相似文献   

17.
The effect of low storage temperature (4 to 8 C) and maleic hydrazide (MH) treatment on sprouting, sucrose and reducing sugar (glucose and fructose) concentrations in tubers, and fry color-sugar relationships of Shepody were determined and compared to Russet Burbank. Sprouting of Shepody was delayed by 3 to 15 weeks when the temperature was lowered from 8 to 6 or 5 C, respectively. Shepody accumulated more sugars at all storage temperatures than Russet Burbank. The reducing sugars accumulated in Shepody at 5 and 6 C could be lowered to levels acceptable for processing for about 24 weeks after harvest by reconditioning at 18 C for at least two weeks. MH increased glucose in Shepody stored at 5 C compared to untreated tubers. Excessive sprouting (> 10 cm sprout length) of nonsprout inhibited Shepody occured late in storage with four weeks reconditioning. Although not statistically significant, MH tended to cause darker fry color per unit of reducing sugar in Shepody compared to tubers from untreated plants. Storage of Shepody tubers not treated with MH could be extended a few weeks by temperatures < 8 C only if there is precise control over temperature, sugars are closely monitored, and reconditioning is rapid to minimize sprouting.  相似文献   

18.
Freshly-cut seed pieces of the potato cultivars Ranger Russet and Shepody were dipped in 0, 0.5, 1 or 2 mg/1 Gibberellic Acid (GA3) prior to planting. GA3 treatments increased stem and tuber numbers per hill of both cultivars and shifted tuber size profile toward the production of more seed-sized (up to 226 g) tubers and fewer large (greater than 340 g) tubers. The effect of GA3 on reducing average tuber size was similar for the two cultivars. Total tuber yields were not affected. A 2 mg GA3/1 seed piece dip decreased the yield of US#1 tubers in Ranger Russet primarily due to a significant increase in yield of tubers less than 226 g. Also, yields of culls were greater after a 1 mg GA3/1 seed piece treatment, suggesting Ranger Russet is sensitive to this concentration of GA3. One and 2 mg GA3/1 seed piece dips to Shepody increased yields of tubers less than 113 g by 93% and reduced the yield of tubers greater than 340 g by 25% to 50%. GA3 at 1 to 2 mg/1 may be useful in the production of seed potatoes with the cultivar Shepody which tends to produce many large tubers.  相似文献   

19.
The study examined the efficacy of 1-methylcyclopropene (1-MCP), an anti-ethylene compound, as a preventative treatment for ethylene-induced fry color darkening in potato (Solanum tuberosum L.) tubers, without reducing the effectiveness of ethylene as a tuber sprouting control agent. The experiment was conducted for two years with ‘Shepody’ and ‘Russet Burbank.’ Tubers of each cultivar from four separate growers received one of the following treatments: Air (control), Air + 1-MCP (1 (μL.L-1 for 48 h), isopropyl N (3-chlorophenyl) carbamate (chloropropham; CIPC; 1% a.i. [v/v]); continuous ethylene (4 μL.L-1) in air; continuous ethylene pre-treated with 1-MCP once; continuous ethylene pre-treated with 1-MCP and repeated monthly; and continuous ethylene pre-treated with 1-MCP and repeated bi-monthly. Treatment started after suberization and cooling to 9 C, and samples were evaluated at 3-wk (year 1) or 4-wk (years 2 and 3) intervals thereafter until April (Shepody) or June (Russet Burbank). Sprout growth (sprout fresh weight per tuber), fry color (Agtron reflectance units), tuber weight loss, incidence of disease infection and internal disorders were evaluated. Weight loss, tuber infection, and the occurrence of disorders were not affected by any of the treatments. Sprout growth was controlled by the continuous ethylene supply in both cultivars, and single or multiple additions of 1-MCP to the ethylene treatment did not affect the ethylene control of sprouting. As expected, ethylene treatment alone enhanced fry color darkening in both cultivars. In Russet Burbank tubers, fry color was not darkened in any of the ethylene + 1-MCP (once, monthly, or bimonthly) treatments. In Shepody, fry color was not darkened in the ethylene + 1-MCP monthly or bimonthly treatments, but started darkening 4 wk after exposure in the single ethylene + 1-MCP treatment. It is concluded that 1-MCP can be used to control fry color darkening induced by ethylene without blocking ethylene control of tuber sprouting. However, the number of 1-MCP applications required may vary with the cultivar, e.g., one application was sufficient in Russet Burbank but not in Shepody.  相似文献   

20.
Alta Russet (Russet Nugget × Ranger Russet) is an early-maturing cultivar, with high yield and excellent processing quality (fry color and dry matter) coupled with a tuber size and shape profile ideal for the manufacture of wedge-cut french fries. In the western Canadian regional trials harvested 110 days after planting, the yield of the new cultivar was similar and the specific gravity superior to that of Russet Burbank. In multi-harvest date trials conducted under irrigated conditions in southern Alberta (Canada) the yield of Alta Russet was superior to Russet Burbank and Shepody and similar to Ranger Russet (Amisk) when harvested at 95 and 110 days after planting. The tuber specific gravity of the new cultivar was superior to Russet Burbank, Shepody, and Ranger Russet (Amisk) at 95 days after planting. At 110 days after planting tuber specific gravity was similar to Ranger Russet (Amisk), but superior to Russet Burbank and Shepody. Fry color was generally superior to Russet Burbank in the western Canadian regional trials and in the multi-harvest trials was generally similar to Russet Burbank, Shepody, and Ranger Russet (Amisk). Alta Russet produces excellent fry color out of long-term storage at 8 C and acceptable color at 6 C. External and internal defects occurred at very low levels in all trials. Alta Russet is resistant to common scab and Verticillium wilt, moderately resistant to early blight and Fusarium wilt and susceptible to Fusarium dry rot and late blight. The new cultivar shows clear symptoms when infected with bacterial ring rot.  相似文献   

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