The effect of soil moisture and nitrogen on yield and quality of the Russet Burbank potato

A study was conducted to obtain more information on the effects of soil moisture and nitrogen on yield and quality of the Russet Burbank potato. Total yield of tubers increased with nitrogen rates as a result of more tubers per plant and larger tubers but the percent of malformed tubers also increased. Increased nitrogen rates decreased of dry matter of tubers and increased the total amino-nitrogen content of the tubers. Placing all of the nitrogen in bands on each side of the row produced more tubers having growth cracks, culls and reduced yield of No. 1’s when compared with broadcasting. Applying a moisture stress to potato plants during the early tuber set period increased the percentage of malformed tubers having pointed stem ends, bottlenecks and dumbbell shapes; although total yield and grade of tubers were not significantly affected. Irrigating when available soil moisture was 75 or 85 percent instead of 65 percent during the growing season did not affect total yield, grade or tuber quality at the five percent probability level.     

Soil oxygen and moisture in relation to Russet Burbank potato yield and quality

On a Declo loam, rooting density, final yield and quality of potatoes (Solarium tuberosum cv. Russet Burbank) showed no significant differences among conventional planting, ripping along the row, or forced aeration 30 cm below the top of the row. There were significant relationships between oxygen diffusion rate (ODR) and soil moisture tension (matric potential) at the 30 and 40 cm depths, but these relationships were not significantly different among treatments. In a complementary experiment, sprinkler irrigations at negative soil water matric potentials of 30–40 (wet), 40–50 (intermediate) and 50–60 kPa (dry,i.e., 0.5–0.6 bar tension) produced no differences in total yield. However, the wet treatment gave significantly more knobby and undersized tubers < 113 g (4 oz.) and a lower percentage of U.S. #1 tubers than the intermediate and dry treatments. Premium sized tubers > 284 g (10 oz.) were significantly higher in the dry than in the wet treatment. Fertilizer N was applied periodically during the season and petiole NO₃-N levels indicated adequate levels with no differences among treatments in either experiment. So much attention has been given to the effects of drought and high temperature stress on the quality of Idaho Russet Burbank potatoes, that some growers may now over-irrigate. Results of this research indicate that attention should also be directed to the effects of excess moisture on the size and quality of tubers.     

Blackspot of Russet Burbank potatoes and the carbon dioxide content of soil and tubers

These studies were designed to elucidate the influence of CO₂ on blackspot susceptibility of Russet Burbank potatoes. The influence of tuber CO₂ environment on blackspot was tested. Tubers from 1–4 and 6–8 inches deep in the soil were scored for blackspot and moisture samples were taken from their vicinity. Blackspot was worse in shallow tubers and in tubers from drier soil. Plowing under corn stover, covering the soil with plastic, and excessive irrigation failed to cause blackspot susceptible tubers. Diffusing CO₂ into the soil atmosphere under plastic sheets slightly increased the intensity of spot discoloration but the discoloration was atypical blackspot. Effects on blackspot by changing tuber gases was tested. Tubers whose gases had been evacuated and replaced by O₂, N₂, and CO₂ had lower blackspot scores than untreated tubers. Increasing the time tubers were soaked in water after gaseous evacuation reduced blackspot. Hydration consistently decreased tuber blackspot. In chemical studies, tubers were tested for blackspot and analyzed for CO₂ content. The relationship between tissue CO₂ and blackspot appeared to be inverse. Tuber CO₂ content was not influenced by time of day. Tuber blackspot scores immediately, 1, 3, and 7 hours after digging were the same, but tissue CO₂ content increased linearly with time after harvest.     

Association of viral,bacterial and fungal pathogens with vascular discoloration of Russet Burbank potato tubers

Russet Burbank potatoes from the 1979 and 1980 crop years, collected from Chicago, IL repack warehouses and retail markets, were sampled for vascular discoloration. The amount of discoloration varied among sampling months and states of origin and decreased from 7.7% in 1979 to 1.6% in 1980. Highest levels of vascular discoloration were detected in December and January samples. Vascular discolored and non-discolored (control) tubers were assayed for the presence of potato leafroll, potato virus X, and beet western yellows viruses by the enzyme-linked immunosorbent assay (ELISA). Tubers were also assayed for 2 subspecies ofErwinia carotovora and forVerticillium albo-atrum andV. dahliae. Potato leafroll virus was detected in 31 of 831 vascular discolored tubers.V. albo-atrum was detected in 1 of 180 discolored tubers. Beet western yellows virus was not detected in discolored or non-discolored tubers. Two subspecies ofE. carotovora and potato virus X were equally common in discolored and non-discolored tubers.     

Response of Russet Burbank potatoes to soil fumigation and nitrogen fertilizers

Two field studies were conducted to determine the effects of soil fumigation on the response of Russet Burbank potatoes (Solanum tuberosum L.) to NH₄-N or NH₄NO₃ fertilizers. In one study fumigation increased yields but N source had no effect. In the other study fumigation had no effect but NH₄-N provided higher yields than NH₄NO₃. Microbial studies indicated that although populations of nitrifying bacteria were initially altered by fumigation, nitrification rates were similar to those in non-fumigated soil. In a controlled environment study in which potatoes were grown in fumigated field soil, neither N source nor fumigation had any effect on growth or yield. These studies indicated that fumigation had no effect on the response of potatoes to NH₄-N or NH₄NO₃ fertilizers.     

Respiration studies on Russet Burbank potato tubers: Effects of storage temperature and chemical treatments

Tubers of Russet Burbank potatoes were stored at 36 F (2.2 C), 42 F (5.6 C), 45 F (7.2 C), 48 F (8:9 C), and 70 F (21.1 C) and respiration rates determined. Chemical treatments 4 with growth regulators were made and respiration rates determined on intact tubers. Tubers stored 42 F (5.6 C) and 45 F (7.2 C) generally respired less and at a more uniform rate than tubers stored at other temperatures. The respiration rate of CIPC and BA (20 ppm) treated tubers was less than the untreated tubers.     

Interactive effects of nitrogen and phosphorus on verticillium wilt of Russet Burbank potato

A three-year field study was conducted during 1984–1986 to determine the interactive effects of nitrogen and phosphorus fertilization on Verticillium wilt, and yield and quality of continuously-cropped Russet Burbank potato. The experiment was conducted on a calcareous, silt loam soil with low initial levels of NO₃-N (0.9 mg/kg), P (3.5 mg/kg), andVerticillium dahliae (9 cfu/g of soil). The experimental design consisted of a factorial combination of three N treatments (unfertilized check, preplant N or split N) and three P treatments (0,120, or 240 kg P/ha) applied to the same plots during the three-year study. Nitrogen was applied at 0 or 300 kg N/ha in 1984 and 0 or 240 kg N/ha in 1985 and 1986. By the spring of 1986, soil P concentrations for the 0,120, and 240 kg P/ha treatments had increased to 7, 25, and 50 mg/kg and no additional P was applied. In addition to suppressing Verticillium wilt by as much as 95%, N & P treatments also reduced the rate of increase of soilborne inoculum ofV. dahliae. After one season of cropping, the N treatment providing the most efficient N fertilization (300 kg N/ha, split-application) resulted in significantly (p=0.01) lowerV. dahliae counts in soil than the other N treatments. After two seasons of continuous cropping, applying 120 to 240 kg P/ha produced lower populations ofV. dahliae in soil compared to the treatment with no added P. Generally, as N and P treatments approached the highest levels, both wilt incidence andV. dahliae colonization values were reduced. There was a progressive reduction in total yield in nearly all treatments during each year of continuous cropping. Reduction of yield and increased Verticillium wilt incidence was generally greater with N or P deficient plants than with optimally fertilized plants. The highest total and U.S. No. 1 yields and least Verticillium wilt were obtained each year by applying split N and 240 kg P/ha. Results show that optimal N and P can minimize both Verticillium wilt and yield losses that normally occur with intensive potato cropping.     

Chlorogenic acid content of Russet Burbank potato in Alberta

Samples of Russet Burbank potatoes, collected from the major production areas in Alberta, were analysed for tuber chlorogenic acid content. Chlorogenic acid is known to be associated with the tendency for tuber tissue to darken after cooking. Results indicate a trend for chlorogenic acid content to decrease from Edmonton in the north to Vauxhall in the south. This may be associated with cooler temperatures and higher soil organic matter in the northerly locations     

The economics of Russet Burbank seed size and spacing

This study is an economic analysis of Russet Burbank seed size and spacing data. Using a representative processor contract, regression analysis was used to estimate the statistical relationship between seed size and spacing and total yield, yield of U.S. No. 1’s, yield of U.S. No. 2’s, yield of 284 gm. and larger tubers, and adjusted grower returns. Depending upon seed cost, the economic optimum seed size ranges from 31 gm. to 48 gm. at 15 cm. spacing. With seed spacing at 23 cm. optimum seed size ranges from 40 gm. to 51 gm. At 31 cm., the optimum size range is 45 gm. to 53 gm. Grower returns adjusted for seed and harvest costs are estimated to be greater at the wider spacing. The results of this analysis have been used to show how grower returns are reduced by variability in seed size and seed spacing. Under normal circumstances, reduced variability in both size and spacing could increase grower returns by $100 per hectare or more.     

Comparison of nitrogen and phosphorus requirements between PVX free and regular Russet Burbank potato seed stocks

A Potato Virus X (PVX) free seed stock resulted in higher total yield and U.S. No. 1 potatoes than regular seed stock which carried PVX. Petiole samples from PVX free seed stock were higher in 2% acetic acid extractable PO₄-P than those from regular seed at all rates of fertilizer phosphorus. A high positive correlation was found between petiole phosphate and yield at early tuber set. Increasing rates of nitrogen increased higher total and U.S. No. 1 yields of potatoes, but also slightly decreased specific gravity. The results of this study indicate that phosphorus fertilizer recommendations for growers using Russet Burbank seed low in PVX will necessarily be different from those made for growers planting ordinary seed.     

Influence of seed placement on Russet Burbank potato yield and grade

Potato seed pieces were hand planted with different spacings in the row and percentages of doubles to determine the effects on total yield and tuber size distribution. The objective was to determine acceptable performance levels for commercial potato planters. Average tuber size increased as the percentage of double seed pieces decreased or as the in-row spacing between single seed pieces increased. Yield of tubers smaller than 113 g was the most sensitive parameter and they increased as in-row spacing decreased and as the percentage of double seed pieces increased. Yield of tubers larger than 283 g increased as in-row spacing increased but only for the first year. Total yield was not affected by the change of in-row spacing or the percentage of doubles.     

Irrigation and soil temperature effects on Russet Burbank quality

Potato growers in the Pacific Northwest suffer large economic losses in seasons with above normal temperatures, due to excess reducing sugars in tubers, which cause dark-end French fries. Our objective was to study irrigation management effects on potato quality, particularly the factors causing dark-end French fries or sugar-end syndrome. Solid-set sprinkler irrigated plots were established on potatoes at Kimberly, Idaho during the 1987, 1988 and 1989 irrigation seasons, and at Parma, Idaho in 1987 and 1988. Irrigation treatments were high and low frequency (3/week and I/week) and two or three water application amounts referenced to estimated evapotranspiration (ET, ET+20%, and ET-20%). Neither frequency nor amount significantly affected yields. Irrigation frequency had more influence on potato quality than application amount. More frequent irrigation produced slightly higher quality tubers and lower incidence of dark-ends when fried. Soil temperature was inversely related to tuber grade quality and directly related to percentage of sugar-end tubers. Soil temperature was about 0.5 C lower under the high frequency than under the low frequency irrigation regime. On these silt loam soils, allowing available soil water to decline to 50 percent had no adverse affect on yield or quality.     

Respiration rates and sugar accumulation in normal and moisture stressed Russet Burbank potatoes

Studies were made on Russet Burbank tubers grown under normal and moisture stressed conditions. Stressing the tubers caused increased reducing sugar accumulation in the basal end during storage. Respiration rates of apical and basal portions of stressed and normal tubers were followed during the growing season and in storage. Although its sugar content was greater, the basal end of stressed tubers respired at a significally slower rate than apical ends from the same tubers. Normal basal and apical portions showed no statistical differences in respiration although the apical end respired at a slightly faster rate than the basal end. A positive linear correlation between sugar concentration and respiration rate of the apical portion was obtained. Differences were found in the abilities of apical and basal ends to alter respiration rates in response to changes in sugar concentration. The resprationof the apical end was the more sensitive to increased sugar concentration. The basal end of stressed tubers lost some of its ability to respond, probably because of increased physiological aging caused by the stress conditions.     

Influence of vine senescence and storage on wound healing of Russet Burbank tubers

Potato (Solanum tuberosum L. cv. Russet Burbank) tubers were harvested weekly over a 6 week period from non-water-stressed and water-stressed plants. Discs were cut from fresh tubers and from tubers stored for 10 days at 4°C to determine their wound healing ability as evaluated by disc resistance to water loss. Neither harvest date nor water status significantly influenced wound healing while storage significantly increased wound healing ability. Enhanced wound healing associated with storage was accompanied by reduced variability of disc resistance to water loss and increased levels of suberin as reflected by the diol and alcohol components. This work suggests that plant senescence and harvest date are not good indicators of the potential wound healing ability of tubers. Physiological evidence is presented to support the practice of short periods of storage following harvest to improve tuber wound healing ability and thereby reduce shipping and handling losses due to injury.     

Petiole analysis and the nitrogen fertilization of Russet Burbank potatoes

The effect of nitrogen rates on the yield of Russet Burbank potatoes was studied in field experiments in Idaho. Petioles were sampled at the 6-to-8 leaf stage and thereafter at two week intervals until mid August. Petiole nitrate concentrations were very high early but decreased rapidly as the season progressed and declined to a very low level as the plants matured. The nitrate content of the petioles reflected the amount of N applied to both locations. Nitrogen applications increased total yield and the quantity of the larger size tubers. A highly significant correlation was found between the early season petiole nitrate concentrations and total yield. Suggested ranges of petiole nitrate concentrations were developed as a guide to efficient N fertilization of Russet Burbank potatoes in Idaho.     

Influences of the Rhizoctonia disease on production of the Russet Burbank potato

Pentachloronitrobenzene (PCNB) treatment (20 lb/A – 22.4 kg/ha) showed significant reduction ofRhizoctonia (Rhizoctonia solani Kühn) symptoms on potato. The PCNB treatment increased the number of non-girdled stolons as compared to untreated plots by 50, 34, and 30% at respective seedpiece spacings of 6, 9, and 12 in (15, 23, and 30 cm). Numbers of non-girdled stolons in PCNB-treated plots at 9- and 12-in spacing did not differ significantly from those in untreated plots at 6-in spacing. Yield differences (either total or U.S. #1) among treatments were not observed, but size differences were evident. Closer spacing or PCNB treatment or both increased the number of small U.S. #1 potatoes and decreased the number of large U.S. #1 potatoes (over 7 oz. - 199 g). Although the number of smaller potatoes was increased by 27% with PCNB treatment, the percentage of malformed tubers was reduced by 50%. Tuber size was reduced as the number of non-girdled stolons was increased (P =.001). Results suggestthat Rhizoctonia control may benefit the fresh potato packer and seedgrower by potentially reducing seed requirement/acre, by increasing capacity for single-drop seed production, and by greater control over U.S. #1 size.     

Seasonal variation of root distribution of irrigated,field-grown Russet Burbank potato

Root density of irrigated, field-grown Russet Burbank potatoes grown on Plainfield loamy sand was determined periodically from soil core samples during the 1973 growing season. Total root length and weight also were measured. Under these growing conditions, the roots essentially were restricted to the plow layer in this soil, decreasing rapidly below this depth. The root density in the plow layer generally ranged from 2 to 6 cm of roots per cm³ of soil, with lower values at greater depths. The root density exceeded 6 cm/cm³ in only a few cores, with a maximum of 11 cm/cm³ obtained on one core in the 10 to 20 cm depth adjacent to the plant. Roots with diameter less than 0.2 mm accounted for about two-thirds of the total root length. A decrease in total root length and dry-weight per plant occurred at the end of the growing season, coincident with the usual decrease in foliage dry weight. The root density beneath the furrow was not significantly different from that within the plant row during most of the growing season.     

Some unique benefits with sudangrass for improved U.S. #1 yields and size of Russet Burbank potato

Three studies provided additional knowledge of beneficial effects of sudangrass for yield and quality increases of the Russet Burbank potato. Two of these studies showed significant increases of both U.S. #1 and smooth tubers > 280 g following green manures of sudangrass. These sudangrass (HS-33) effects did not differ from a sorghum-sudan hybrid (Trudan-8). When a sudangrass green manure was compared with a fallow treatment, results of the first study showed mean yield increases of 36% for U.S. #1 tubers > 280 g and yields of a second study by 34% for U.S. #1 tubers. This same sudangrass treatment outperformed green manures of either Austrian winter pea, barley, or sweet corn by increased U.S. #1 yields that ranged from 27% to 61%. By several lines of evidence, these benefits were found to extend beyond the effect of Verticillium suppression. Soil N was significantly increased following green manures of sudangrass, and these increases were in turn negatively correlated with wilt incidence and positively correlated with yields of both U.S. #1 tubers and tubers > 280 g. Additional benefits also included significant increases of tuber grade percentages for marketable tubers and of smooth tubers > 280 g. Benefits from sudangrass green manures beyond the effects of Verticillium suppression became further evident following a greenhouse study that involved field soil and sudangrass that had been grown in the same field. This study corroborated both field experiments by showing increased yields with green manures of sudangrass that approximated 5.5 t ha^-1 dry wt. As with the field studies, these yield benefits also extended beyond the effects of Verticillium suppression and were closely associated with significant increases ofFusarium equiseti, F. oxysporum, andF. solani. Throughout all studies, sudangrass green manures significantly increased microbial activities with increased populations ofFusarium spp. and increased concentrations in soil of mineralizable N, organic P, K, Mn, along with the percent soil organic matter -all factors that could have contributed to significant increases of yield and quality.