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1.
A study was carried out with potato (Solanum tuberosum; cv. Atlantic) during 2001 and 2002 to determine the effect of soil salinity on internal tuber browning. The effect of varying levels of soil salinity on proline content, polyphenol oxidase enzyme activity, and chlorogenic acid content in potato leaves and tubers was examined. NaCl treatments (2.1, 4.25, 6.38, 8.5 g NaCl L?1) were applied to the pots, the first 46 days after planting, and four additional treatments were applied, each about 7 days apart. Increasing NaCl concentrations resulted in an increase in browning of tuber tissue and proline content in the tubers. Chlorogenic acid content in the leaves increased up to 6.4 g NaCl L?1, but then decreased at 8.5 g NaCl L?1 and in tubers tended to be maximal at the highest saline concentration tested (8.5 g NaCl L?1). Increasing NaCl concentration resulted in a reduction in yield per plant and average tuber weight, and also increased tuber number. There were major differences in the impact of salinity over the 2-year period, which was probably due to the impact of the growing media; a low organic matter (about 1% OM) silty loam soil and a high organic content (about 90% OM) Muck soil were used in 2001 and 2002, respectively. Tuber browning increased linearly with salinity in 2002, but only markedly increased at 8.5 g NaCl L?1 in 2001. Sodium and chloride ion concentration was always greater (about two times) at equivalent application rates in the 2002 trial. The high organic matter content soil retained sodium and chloride ions more effectively than the silty loam soil and enhanced the impact of increased salinity concentration on physiological properties of potato plants and particularly on tuber tissue browning and proline accumulation.  相似文献   

2.
Summary The effect of fungicides and the antagonistic fungusTrichoderma harzianum (Th) on the potato leak pathogenPythium aphanidermatum (Pa) was investigated in vitro. Rot was reduced by 73% to 89% when tubers inoculated withPa were treated by immersion in solutions (0.5% w/v) of the fungicides Ridomil MZ58. Dithane M45. Manebe 80 and Tachigaren 360. Complete protection was achieved by dusting inoculated tubers with Ridomil MZ58 diluted in kaolin at a final concentration of 0.1% (w/w). The biological treatments of dipping inoculated tubers in a conidial water suspension ofTh at 108 conidia/ml or of dusting with a mixture of a barley culture ofTh and kaolin to a final concentration of 2×109 conidia/g were as effective as the chemical treatments. Control was still effective when inoculated tubers were treated with Ridomil MZ58. Tachigaren 360 or the conidial suspension ofTh after 24h incubation at 25°C.  相似文献   

3.
《Field Crops Research》2002,74(1):81-91
Despite the economic importance of tobacco, there is limited field study on the quantitative response of growth and yield to increasing soil salinity. The effects of irrigation with saline water on yield components of field-grown tobacco (Nicotiana tabacum L.) “Burley” type plants were studied over two growing seasons. Growth, dry matter partitioning and gas exchange were measured either in rainfed or fully irrigated plants growing in a clayey–sandy–loam soil. The four fully irrigated treatments received amounts of saline waters at 0.54, 2.5, 5.0 or 10 dS m−1 electrical conductivity (ECw) equal to crop evapotranspiration. In both years, the electrical conductivity of the saturation phase (ECe) across the 0.6 m topsoil profile increased with increasing salinity of the irrigation water. Soil moisture was markedly lower in the rainfed treatment than in fully irrigated treatments. Different saline concentrations of irrigation water had virtually no effect on soil moisture. Carbon assimilation rate, stomatal conductance and water use efficiency of the saline treatments were lower than the fully irrigated plants at 0.54 dS m−1 (NW treatment) in 1996, but not in 1997. Transpiration rates were unaffected by salinity in both years. The highest yield was produced by plants irrigated with good quality water. The number of leaves per unit land area was greater for the NW plants, whereas there were no differences between the other four treatments. Salinity decreased plant dry matter and height at harvest, increased dry matter partitioning into leaves and decreased that into stems in both years. Dry matter partitioning to leaves was also greater for the rainfed plants than for the NW plants. Tobacco plants grown under field conditions showed a maximum reduction of relative yield at the highest salinity level of only 31%. The threshold values (0.56 and 0.96 dS m−1) and the ECe at which a 10% yield reduction was obtained (3.12 and 2.55 dS m−1) calculated from the linear model of response of relative yield to increasing ECe were typical of moderately sensitive crops. The ECe values at which 50% yield was reduced (13.34 and 8.91 dS m−1) were indicative of moderate tolerance to salinity.  相似文献   

4.
《Field Crops Research》2005,92(1):75-84
The effect of irrigation with saline water on quality of Burley tobacco (cv. C 104) was investigated in Southern Italy over four consecutive years. A rainfed control (RC) was compared with treatments irrigated with volumes equal to crop evapotranspiration of saline waters at 0.5 (NW), 2.5 (SW1), 5 (SW2) and 10 (SW3) dS m−1 electrical conductivity (ECw). In 2000 and 2001 an additional salinity treatment (15 dS m−1 ECw) was included (SW4). The amounts of Cl− added to the soil by irrigation ranged from 36.3 kg ha−1 (good quality water in 1999) to 16.2 Mg ha−1 (saline water at 15 dS m−1 ECw in 2000). Saline irrigation did not affect yield and yield components of cured leaves. In 1998 and 1999 the filling power of Burley tobacco did not change significantly with increasing salinity of the irrigation water. In 2000 and 2001 the filling power of SW2, SW3 and SW4 treatments was significantly less than that of NW. The Cl− content of tobacco grown with SW2 was significantly greater than that grown with NW and there were no differences between SW1 through SW4 treatments. The filling power and the leaf Cl− content were inversely related to the amount of Cl− applied in the range between 40.3 kg ha−1 and 5.1 Mg ha−1. The filling power decreased and Cl− increased up to the SW2 treatment; beyond that level neither Cl− nor filling power changed in response to increasing amounts of Cl− applied. The leaf alkaloid content was unaffected by salinity. Total N was unaffected by either the growing season or the saline treatments. Cigarettes obtained from saline treatments did not burn during the smoking test in 1998. In 1999 cigarettes made from SW1 and SW2 did burn, but those from SW3 did not. In 2000 and 2001 the smoking test was performed only on commercial blends containing 10 or 30% of cut tobacco from saline treatments and both blends burned similarly to cigarettes made entirely from tobacco grown under non-saline conditions. In conclusion, quality of Burley tobacco was unaffected by irrigation with saline water at 2.5 dS m−1 and the inhibitory effect of salinity on burning properties could be overcome by appropriate mixture in commercial blends.  相似文献   

5.
Summary Applying saline solutions (EC 3.2 up to 7.0 dS/m) to seed tubers of different cultivars planted in tuff delayed shoot emergence and root and shoot development. Fresh weight of most cultivars was decreased by 60% but cv. Serrana Inta was more tolerant to salinity and fresh weight was decreased by 20%. When planted in 500 cm3 pots containing loessial soil some seed tubers rotted and plant growth was severely inhibited, possibly because soil aeration was impeded. Physiologically ageing seed tubers for 33 days at 6°C decreased sensitivity of most cultivars to moderate salinity whereas ageing for 68 days increased sensitivity to high salinity. Contribution from the Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel. No. 2977-E, 1990 series.  相似文献   

6.
Summary Foliar applications of ethephon (ETH) 300 g a.i. ha−1; chlormequat chloride (CCC) 920 g a.i. ha−1, with a second application of 230 g a.i. ha−1 approximately 2 weeks later; and a mixture of the two (ETH/CCC) 156 g a.i. ethephon and 299 g a.i. chlormequat chloride ha−1 were made to field-grown Russet Burbank potatoes in 1986, 1987 and 1989. All the treatments increased the number of tubers set and reduced the average tuber weight compared to the control resulting in a reduction in premium and marketable tubers, and an increase in small tubers. Differences were greatest for ETH and least for CCC. ETH and ETH/CCC decreased the specific gravity, increased the incidence of deformities, and decreased the incidence of tubers with hollow heart. The growth regulators did not affect fry colour.  相似文献   

7.
Summary Pot and field experiments were carried out to test fertilizer treatments on the behaviour of potato tubers stores at 4°C and ≥90% relative humidity for 6 months. Weight losses (separated into water and dry matter) were enhanced after N and K fertilization and decreased by increasing P supply. Glucose and fructose contents were reduced at harvest by high N-fertilizer rates compared to no or low fertilization, but throughout storage reducing sugar accumulation was increased, sucrose reduction was decreased and ascorbic acid was increased. K fertilization affected the chemical composition of the tubers somewhat similar to that of nitrogen fertilization. High initial nitrate content of the tubers seemed to be increased and low nitrate values were decreased during storage. The tubers from pot experiments showed similar changes but of greater magnitude.  相似文献   

8.
Summary Calcium levels in the periderm of tubers (cv. Sebago) growing in irrigated sands were influenced by the stem position at which the tuber grew, but the effect was not consistent over two seasons. Calcium levels were increased at all tuber positions by addition of calcium to soil; combined treatments of gypsum (1400 kg Ca2+/ha) pre-plant and calcium nitrate (37 kg Ca2+/ha) side dressings gave the greatest response. Percentage incidence of soft rot lesions caused byErwinia chrysanthemi pv.zeae was not influenced by periderm calcium content. The severity of infection (weight of tissue macerated within 48 h at 30°C) was significantly reduced only by the pre-plant gypsum treatment, but there was no correlation with calcium content of the periderm. Calcium levels in periderm tissue (60–208 mg Ca2+/100g) are within the range of published data for other cultivars and results support previous reports that the correlation between tuber susceptibility toErwinia spp. and periderm calcium content is inconsistent.  相似文献   

9.
The potential for bacterial soft rot in potato tubers was affected by laboratory simulation of some components of fluming and washing practices at commercial packinghouses. The potential was expressed as disease severity (average percentage surface decayed) after a standard 4-day incubation at 20°C in a mist chamber. Increased disease resulted when there was an increase in the following factors: a) duration of immersion of tubers in water; b) population of bacteria suspended in water; c) hydrostatic pressure on submerged tubers, and d) concentration of a surfactant (Triton X-100) in the suspensions. A sample of tubers from each tuber lot was uniformly moistened with tap water and then incubated to determine a base-level disease severity. Disease severity in Russet Burbank tubers from commercial storage increased from the base-level of 0.8% to 76% when tubers were immersed in 5 × 106 colony-forming units (cfu)/ml ofErwinia carotovora pv.carotovora (Ecc) for 64 min prior to incubation. Disease severity was 64% when tubers were immersed in a similar suspension for only 0.1 min, but with a hydrostatic pressure of 230 cm of water. Severity values fourto fivefold above control levels (from immersion in water) resulted from an immersion for 5 min in 5 × 103 cfu/ml with hydrostatic pressures of 5, 180, or 370 cm of water. A 20-fold increase in severity occurred when Red LaSoda tubers were immersed briefly (less than 5 s) in 5 × 106 cfu/ml. Rinsing these tubers with tap water after inoculation, but prior to incubation, did not affect the subsequent development of decay. Thus, the high potential for bacterial soft rot in tubers that have been flumed or washed by water concentrated with soft rotErwinia cannot be reduced by washes or rinses with clean water.  相似文献   

10.
In studies on a sandy soil in Florida over a 3-yr period (1984–86), applications of Ca (CaSO4) inconsistently affected the bacterial soft rot potential of potato tubers (Solanum tuberosum). The potential was estimated from the severity of the disease (percent surface area decayed) in tubers that had been immersed in an aqueous cell suspension ofErwinia carotovora subsp.carotovora and then incubated 4 days in a mist chamber at 24 C. With freshly harvested tubers (tested within 5 days after harvest), disease severity averaged 49, 11, and 4% over all treatments in 1984, 1985, and 1986, respectively, which was roughly proportional to rainfall on the crop,e.g., 37, 18, and 15 cm, respectively. Disease severity decreased, did not change, and increased with increased Ca rate (0, 450, and 900 kg.ha-1) in 1984, 1985, and 1986, respectively. In each season, severity was affected by interactions involving the Ca treatments. Most interactions involved cultivar. The efficacy of Ca applications to potatoes grown in low Ca soils for enhancement of tuber resistance to bacterial soft rot may be limited by factors associated with environment or cultivar that are not completely understood.  相似文献   

11.
Summary

Use of saline drainage water for crop irrigation was evaluated as a means of decreasing its volume. Results of a nine-year crop rotation (cotton-cotton-safflower, × 3) in which only the cotton was irrigated with drainage water of 400, 1,500, 3,000, 4,500, 6,000, and 9,000 ppm total dissolved salts are presented. The different salinity levels of irrigation waters were achieved by mixing nonsaline canal water (400 ppm) and saline drainage water. Cotton lint yields were not affected by increased salinity level of the irrigation water for the first two years. Detrimental effects became evident in the third cotton crop with increasing severity in later years. In the fifth year of cotton (seventh year of the study), lint yields were adversely affected by waters of salinity greater than 3,000 ppm. However, fiber quality remained unaffected at all levels of irrigation water salinity. The reductions in lint yield appeared to be a function of time and the salinity level of applied water. Shoot height and biomass were reduced by the irrigation water salinity before lint yields. Stand establishment appeared to be the most sensitive to salinity and was perhaps the main reason for yield reduction. Increase in irrigation water salinity increased Na+ content of leaf blades and petioles and decreased K+/Na+ ratio of leaf blades and petioles. The study showed that irrigation waters of up to 3,000 ppm salinity may be used for four years without any yield reductions, as long as some leaching occurs through preplant irrigations with low salinity water. Data on crop growth and development and ionic content collected over the nine year period are presented.  相似文献   

12.
Management practices that accelerate crop development and allow earlier harvest would be beneficial in short-season potato (Solanum tuberosum L.) production areas. Yield and quality of the potato cultivar ‘Russet Burbank’ were evaluated in a 2-yr study in northern Maine to determine effects of soil tillage and seedsprouting treatments designed to dry soil early in the spring and hasten seed emergence. The tillage treatments, consisting of fall raised bed (RB), fall ridge till (RT), and spring chisel plow (CH), were tested in combination with green-sprouted and non-sprouted seed tubers on a Caribou gravelly loam (coarse-loamy, mixed, frigid,Typic Haplorthod). Plants from green-sprouted seed emerged earlier than from non-sprouted seed tubers (87%-96% vs 21%-37%, respectively, at 18 days after planting [DAP] in 2000; and 73%-88% vs 18%-23%, respectively, at 20 DAP in 2001). Green-sprouted seed tubers in RB yielded 4.6 to 5.9 T ha-1 more than nonsprouted seed tubers in RB. However, non-sprouted seed tubers yielded higher than green-sprouted seed tubers in RT by 2.9 to 4.2 T ha-1 and in CH by 1.1 to 4.1 T ha-1. Similarly, green-sprouted seed tubers in RB and nonsprouted seed tubers in RT and CH produced higher marketable yield, greater tuber length, and greater tuber diameter than the corresponding seed-sprouting treatment. In the comparatively wetter year (2000), the use of green-sprouted seed tubers in RB significantly increased total and marketable yields, and produced longer and larger tubers than all other treatments. However, in 2001 (relatively dry year), yield and quality from green-sprouted seed tubers in RB did not differ from non-sprouted seed in RT or CH. Green-sprouted seed produced fewer sunburned and rotten tubers, but more misshapen tubers than non-sprouted seed in RB tillage. The technique of producing Russet Burbank potatoes in raised beds is a promising system in regions with short growing seasons for enhancing early soil drainage during spring and improving soil water retention during critical periods of crop growth and development.  相似文献   

13.
Summary Potato seed tubers may suffer from premature sprouting during storage, thus limiting their suitability for cultivation. Commonly used sprout suppressant treatments negatively affect but viability and therefore a reliable method to inhibit bud development must still be found for seed tubers. The monoterpene carvone ((S)-(+)-carvone) was tested in small scale experiments. The vapour of this compound fully inhibited bud growth of tubers cv. Monalisa stored at 23°C without affecting bud viability throughout 6 months of treatment. The most effective range of carvone vapour concentrations was between 0.34 and 1.06 μmol mol−1. With these qualities we can expect carvone to become a suitable sprout suppressant for seed tubers.  相似文献   

14.
Based on ethylene management in potato storage, we hypothesized that the applied treatments would modify number of sprouts per seed tuber. Thus, in combination with in-row spacing (closer for seed, wider for processing) in the field treatments will give either (1) a high number of small tubers destined for seed use, or (2) a relatively smaller number of large, uniform tubers suitable for processing. A three-year study (2001–2003), conducted with two french fry processing cultivars, Russet Burbank (RB) and Shepody (SH), aimed at the development of a novel modified atmosphere seed tuber storage treatment. Seed tubers were stored at 4 C from October to May of each year in a cold room under five modified atmospheric regimes: (1) air ventilation only (Control); (2) 4 µl L?1 ethylene applied continuously beginning in November and (3) beginning in February; (4) 1 µ1 L?1 MCP (1-methylcyclopropene) applied as a gas for 48 h only in early December followed by continuous 4 µl L?1 ethylene and (5) MCP alone applied as above. Each year, once a month (mid-January until end of April), a number of seed tubers was taken from each storage treatment, planted to pots and grown for 4 wk in a growth-room. In these studies, shoot emergence from the ethylene-treated seeds of both cultivars occurred significantly earlier, giving higher number of stems per tuber and stolons per stem than Control and MCP treatments. Moreover, the time to emergence after planting decreased with the increased length of storage. Field studies that were conducted from the end of May (planting) until October each year, produced similar trends (although not significant atP≤0.05) and resulted in a higher number of tubers per stem. In RB at the closer in row spacing (30 cm) used for seed production, ethylene enhanced yield of smaller tubers in the 30- to 115-g and 115- to 300-g categories. The ethylene storage treatments also increased tuber number per plant, but not the total mass of harvested potatoes. The MCP treatment, in combination with the wider in-row spacing (40 cm) used for the production of processing tubers, significantly increased the percentage of large tubers (>300 g). In SH, contrary to RB, the ethylene treatments did not alter tuber size distribution and the application of MCP reduced tuber size rather than increasing it. Results from this study suggest that both ethylene and MCP can be used in seed potato storage to influence the tuber size distribution of the crop from that seed.  相似文献   

15.
Summary Minitubers can be produced in large quantities by repeated harvesting of tubers from in vitro propagated plantlets at 4, 7 and 10 weeks after transplanting to the glasshouse at high plant densities. Yield parameters of minitubers can be manipulated by crop husbandry. By supplying nutrients or using a square plant arrangement, minituber yield increased. Effects on numbers of tubers were cultivar-dependent. Changing plant density from 50 to 800 plants per m2 or the minimal diameter of harvested tubers from 5 to 12 mm did not significantly affect tuber yield per m2. Higher plant densities resulted in more tubers per m2 but fewer tubers per plant. Removing smaller tubers greatly increased the number of small tubers, but did not affect yield and number of tubers in larger grades. Crop husbandry techniques affected minituber yield mainly through their effects on leaf area duration, and the number of minitubers through their effects on growth of tubers to a harvestable size.  相似文献   

16.
Summary The effect of varying plant population on the production of tubers from potato seedlings was investigated during 1992 and 1993 using three different plant densities: 35, 70, 100 plants/m2. Increasing the plant population significantly increased the number of tubers produced, but no significant difference was found between the plant densities of 70 and 100 plants/m2. The seedling tubers produced in nursery beds were tested in the field for ware potato production using different sized tubers. The best performances were obtained using tubers 30–40 mm. Significant differences were evident among the 7 true potato seed (TPS) families used, but data grouped by type of cross did not indicate any significant difference between 4X×4X and 4X×2X crossing groups.  相似文献   

17.
A. Ester  R. Trul 《Potato Research》2000,43(3):253-261
Summary After a wet autumn and harvesting under wet conditions, slugs brought into potato stores via clods and soil adhering to tubers may cause substantial damage by feeding on the tubers. A carvone sprout inhibitor, Talent?, applied in the potato stores at a dose of 50 ml per tonne potatoes, controlled slugs within a few days. A dose of 25 ml carvone was insufficient. Using a laboratory box test, the slug (Deroceras reticulatum) affected only wounded tubers and, although slime was present on the unwounded potatoes, they were not damaged by slugs.  相似文献   

18.
Gibberellic acid (GA3) powder was applied to seed pieces of Shepody potato in combination with water, fir bark and talc carriers. In a greenhouse study, emergence, stem growth and tuber number from seed pieces treated with dry GA3 and carriers were compared with that of an untreated control. All carriers alone reduced stem emergence. GA3 (0.5,1 and 2 mg/ kg) combined with talc, and 0.5 and 2 mg GA3/kg with fir bark+talc enhanced emergence. Only 2 mg GA3/kg enhanced emergence when applied in solution. Emergence of stems from pieces treated with GA3 and fir bark was no different or slower than the control. In the absence of GA3, water and talc increased stem number and fir bark-containing treatments reduced tuber number. All concentrations of GA3 applied with talc or fir bark+talc, and 2 mg GA3/kg with fir bark increased stem and tuber number. With water, 0.5, 1 and 2 mg GA3/kg increased stem number but only 2 mg GA3/ kg resulted in more tubers. One and 2 mg GA3/kg combined with talc resulted in the most stems and tubers 58 days after planting. GA3 was as effective or more effective in speeding emergence and increasing stem and tuber number when applied in the dry form with talc or fir bark+talc as when applied in solution.  相似文献   

19.
Summary The viability of five pathogens was decreased by treatment with hot water when tested in vitro.Polyscytalum pustulans was most sensitive andRhizoctonia solani least sensitive. Potato tubers were exposed to 55°C for 5 min in a commercial continuous hot water treatment plant using naturally contaminated seed tubers and tubers which had been inoculated by dipping in comminuted cultures. The frequency of eyes colonised byP. pustulans, Helminthosporium solani, andR. solani was reduced to virtually zero and the effect persisted on tubers subsequently stored at 4°C and at 15°C for up to 16 wk. Results withColletotrichum coccodes were inconclusive. Treatment suppressedPenicillium spp. which, however, rapidly recolonised the eyes during storage, leading to higher contamination levels in the treated than in the untreated tubers. With tubers inoculated withPhoma foveata, good control was achieved when the incubation period before treatment was 10 d but not when the period was 42 d.  相似文献   

20.
The possibility that sugar accumulation of potatoes stored at low temperatures may be linked to activation of cyanide-resistant respiration (CRR) was investigated. After a lag period of several days, continuous HCN treatment stimulated CO2 production of tubers stored in 20% O2. At 1°C in 20% O2, HCN treatment increased respiration over that effected by low temperature treatment. After several weeks of treatment, cyanide-stimulated CO2 production was greater at 1°C than at 10°C. Sucrose and malate levels of HCN treated tubers were sometimes higher than those of the 10°C control tubers, but they were always lower than those of the 1°C control tubers. This indicated that CRR alone could not account for the sugar increases at 1°C. Storage in 2% O2 blocked the increase in CO2 production and changes in constituents associated with HCN treatments in 20% O2. HCN treatment had no significant effect on chip color. The level of CRR was measured in freshly cut slices from Monona, Norchip, and Kennebec tubers previously stored at 10°, 5°, or 1°C for several months. Slices from tubers previously stored at 1°C had increased CRR, but there was no difference in CRR between the 5°C and 10°C treatments. Sugars accumulated at 5°C, again indicating that sugar accumulation in potatoes stored at low temperatures was at least partially independent of the activation of CRR.  相似文献   

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