共查询到20条相似文献,搜索用时 15 毫秒
1.
A study was conducted on sand and loam soils to evaluate the response of three potato cultivars to subsoiling and irrigation frequency. Subsoiling was of little benefit on the loam soil. On the sand, subsoiling promoted deep rooting and allowed potatoes to avoid water stress usually associated with four days between irrigations. Russet Burbank was much more sensitive to water stress than was Nooksack or Lemhi, especially in the percentage of tubers not graded U.S. No. 1. Benefits from subsoiling may be inadequate to justify the cost if a reliable high-frequency irrigation system is available. 相似文献
2.
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
3.
Summary When the potato cultivars Arran Banner, Bintje, and Compagnon were inoculated with Azotobacter chroococcum in Libya, only Arran Banner responded significantly; plant growth was stimulated and the yield of marketable tubers increased
by 8.5–42.6% above the untreated control. The very large yield increase in one season was associated with unfavourable growing
conditions.
Zusammenfassung Im Herbst 1975, im Frühjahr und im Herbst 1976 wurden in Tripolis. Libyen, drei Versuche durchgeführt, um den Einfluss der
Inokulation von Pflanzkartoffeln mitAzotobacter auf das Wachstum und den Ertrag von drei Kartoffelsorten (Arran Banner, Bintje und Compagnon) zu untersuchen. Nur bei der
Sorte Arran Banner ergab sich eine Beeinflussung durch die Inokulation mitAzotobacter (Tabelle 1 und 3). Der Ertrag war in den drei Versuchen um 42.6% 17.4% bzw. 8.5% gesteigert. Die st?rkste Reaktion ergab
sich im ersten Versuch. bei dem niedrige Temperaturen und Bew?lkung vorherrschten und die Wachstumsbedingungen für die Kartoffeln
im allgemeinen ungünstig waren. Die Sorten Bintje und Compagnon zeigten keine signifikante Steigerung des Ertrages nach der
Inokulation. Die Inokulation erh?hte die Stengell?nge, hatte aber keinen signifikanten Einfluss auf die Stengelzahl pro Pflanze
(Tabelle 2).
Z?hlungen im Boden der Rhizosph?re zeigten. dass nach Inokulation des Pflanzgutes mitAzotobacter die Population in der Wurzelzone anstieg (Tabelle 4). Die Ertragssteigerung nach der Inokulation scheint durch eine Anreicherung
vonAzotobacter in der Rhizosph?re intokulierter Pflanzen hervorgerufen zu sein.
Résumé Trois expérimentations ont été menées à Tripoli en Libie afin d'étudier l'effet de l'inoculation de tubercules de semence
avecAzotobacter sp. sur la croissance et le rendement de 3 variétés de pomme de terre (Arran Banner, Bintje et Compagnon).
Ces essais se sont déroulés durant l'automne 1975, le printemps et l'automne 1976. Il n'y a eu que la variété Arran Banner
qui a répondu de manière conséquente à l'inoculationd'Azotobacter sp. (tableaux 1 et 3).
L'augmentation de rendement a été respectivement de 42.6%, 17.4% et 8,5% dans les 3 expériences.
La meilleure réponse a été obtenue dans la première expérimentation où des températures basses et des jours couverts ont dominé
et où les conditions de végétation ont été généralement défavorables à la pomme de terre.
Les variétés Bintje et Compagnon n'ont pas montré d'augmentation significative du rendement avec inoculation.
L'inoculation parAzotobacter sp, augmente la longueur des tiges, mais n'a pas d'effet significatif sur le nombre de tiges par plante (tableau 2).
Les comptagesd'Azotobacter sp. dans la rhizosphère ont indiqué que l'inoculation de la semence augmentait la populationd'Azotobacter au niveau de la zone racinaire (tableau 4). Cela est probablement d? au fait que l'augmentation du rendement grace à l'inoculation
résulte d'une meilleure adaptationd'Azotobacter sp. au niveau de la rhizosphère des plantes inoculées.
相似文献
5.
A 3 years field trial examined the effect of newly and previously applied lime on the growth and yield of two near-isogenic wheat genotypes differing only in aluminium (Al) tolerance ( Triticum aestivum L. Al-sensitive line ES8 and Al-tolerant line ET8), and barley ( Hordeum vulgare cv. Mundak) on an acid soil (pH CaCl2 4.6 in 0–10 cm and pH 4.1–4.3 in 10–40 cm) in the medium rainfall region of Western Australia. The trial consisted of four lime treatments: (i) no lime control; (ii) surface liming at 1.5 t ha −1 in 1999; (iii) surface liming at 2.5 t ha −1 in 1984; (iv) liming in 1984 and re-liming in 1999. Wheat crops were grown in 1999 and 2001, and barley was grown in 2000. Liming in 1984 increased the pH in both topsoil and subsoil and decreased toxic Al in the subsoil. Liming in 1999 largely increased soil pH in the 0–10 cm in previously unlimed and limed plots, but only slightly increased the pH in 10–20 cm 2 years after application. In 1999, there was an overall 14% grain yield increase by growing ET8, mostly due to much better performance (41%) of ET8 over ES8 in the treatment with surface liming in 1999. In 2001, ET8 had yield 24% higher in the no lime control and 14% higher in the treatment with liming in 1999 compared with ES8. While both genotypes had similar root length density in the topsoil, root length density in acid subsoil was 22–160% higher for ET8 than for ES8. Wheat genotypes produced 23–24% higher yield due to the liming in 1984 compared to the no lime control. In 2000 season, shoot biomass of barley increased by 45–70% in the limed treatments compared with the no lime control. Liming at 2.5 t ha−1 in 1984 or liming at 1.5 t ha−1 in 1999 increased yield by 25%. Liming in 1984 and re-liming in 1999 increased the yield by over 50%. The results suggest that surface liming can ameliorate subsoil acidity as measured 15–17 years after application, and that growing an Al-tolerant crop in combination with surface liming provides a good strategy to combat subsoil acidity. The genotypic variation in response to liming appears to result from the difference in the sensitivity of root proliferation to low pH and high Al. 相似文献
6.
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 (NO 3-N) concentration, and specific gravity of the cultivars Shepody and Russet Burbank. Nitrogen fertilization increased the average fresh tuber weight, tuber N and N0 3-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 NO 3-N concentrations. Tuber NO 3-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 NO 3-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 NO 3-N concentration are greater when fertilization exceeds the N requirements to reach maximum tuber yield. 相似文献
7.
Summary Leaf stomatal resistance varies considerably in response to changes in environmental conditions. Understanding cultivar differences
in the response of stomata to these conditions is important for effectively simulating water-use and growth.
In this study the stomatal resistance of three field grown potato ( Solanum tuberosum L.) cultivars Atlantic. Monona and Norchip was observed in response to photosynthetic photon flux density, leaf to air vapour
pressure difference and root zone available soil water. Substantial variation in stomatal resistance was accounted for by
functions of the environmental variables for both Monona and Norchip. The explained variation for Atlantic was considerably
less. Light saturation occurred near 500 μmol m −2 s −1. Increasing stomatal resistance above 1000 μmol m −2s −1 was also observed but is likely an artifact of stomatal closure on days in which mid-day leaf water potentials dropped below
critical levels. Although the leaf presumably insufficient to obtain substantial effects. The soil water status was partially
linked to the average 1000 h to 1500 h stomatal resistance on clear, sunny days. Significant differences were observed among
the cultivars in the response of stomata to changes in the available soil water. 相似文献
9.
Summary Assessments were made in three seasons of yields and tuber dry-matter percentages at harvests from June to early August in
a range of cultivars gorwn at a coastal site in south-west Wales. Lareg differences in tuber dry-matter percentage were found
between cultivars within seasons and also at similar dates between seasons.The cultivar Home Guard produced consistently high
dry-matter percentages each year in the period from late June to early August but cv. Redord achieved similar or higher dry-matter
contents after mid-Julyl. Most other cultivars produced lower dry matter percentages throughout the sampling period. The potential
for the use of early maturing cultivars in late June and July for processing into crisps is discussed. 相似文献
10.
Summary Different nitrogen sources (NO 3
−, NH 4
+, glutamic acid and their combinations) influenced the growth and morphogenic responses (node number, shoot length, and stem,
leaf and root dry weight) of three micropropagated potato cultivars (Spunta, Kennebec, Huinkul).
Addition of reduced nitrogen (NH 4
+ or glutamic acid) in a nitrate medium increased shoot length and leaf number. The large increase in growth in plants fed
with NO 3
−, NH 4
+ could be explained by higher organic nitrogen content and enhanced dry matter partition to the shoot. This suggests that
reduced nitrogen source is required, at least as a supplement to NO 3
−, to enhance N assimilation and growth. 相似文献
11.
Summary Plants of early potato cultivars were sampled at successive harvests during tuber development and individual tubers were analysed
for α-solanine and α-chaconine using high-performance liquid chromatography. Mean tuber total glycoalkaloid concentration
(α-solanine plus α-chaconine) per plant decreased with time and statistically significant differences between cultivars were
observed in the patterns of decline during tuber growth. The mean tuber ratio of α-chaconine to α-solanine increased during
tuber development and was also affected by genotype. Total glycoalkaloid concentration for individual tubers of marketable
sizes (up to 50 g fresh weight) exceeded the safety limit of 20 mg per 100 g fresh weight for cultivars Home Guard and British
Queen but not for Rocket. These differences were attributable to differences in both rates and patterns of glycoalkaloid accumulation
during tuber development, although in all cultivars results were consistent with glycoalkaloid accumulation occurring in the
expanding peripheral cell layers of tubers for a considerable period after tuber initiation. 相似文献
12.
The plant growth regulator, daminozide, was applied to the foliage of Ranger Russet, Shepody and Nooksack potato ( Solarium tuberosum L.) plants at 0, 0.62, 1.25, 2.5 and 5 g product·liter ?1 to determine its effectiveness in increasing eye number and reducing average tuber weight. Total tuber yields were not affected. Daminozide treatment increased tuber eye number of each cultivar and did not alter the distribution of eyes between the stem and bud ends. After 5 g daminozide·liter ?1 treatment, average eye number of the stem end and bud ends of Nooksack increased up to 1.0 eye, by 27% for Shepody and by 31% for Ranger Russet. The largest increases in eye number occurred in Ranger Russet. However, increasing daminozide concentration caused increased tuber elongation in Ranger Russet. Average tuber weight decreased significantly in response to daminozide treatment only in Shepody. As a seed tuber production aid, daminozide can be used to increase eye number, and in some cultivars, to reduce average tuber weight. 相似文献
13.
Summary A heat balance method for measuring sap flow in actively growing plants was tested on three potato ( Solanum tuberosum L.) cultivars Monona, Norchip and Atlantic. The method is based on applying a known heat source to the stem of an intact
plant: by measuring the axial and radial heat dissipation the magnitude of sap flow can be quantified. The technique shows
promise as 24 h accumulated sap flow measurements were highly correlated (r 2=0.935, n=36) with gravimetric measurements of transpiration and produced an average root mean square error (RMSE) of 20 g
d −1. The accuracy of the method improved as daily accumulated flow increased. Under low daily flow rates overall RMSE increased,
supporting the need for a heat storage term in the heat balance equation. Short term flow rates were less significantly correlated
(r 2=0.764, n=1572) and produced an average RMSE of 2.89 g h −1. Identification of these short term flow rates during high flow periods may be difficult. The presence of water potential
gradients and the likelihood of re-hydration during high flow events may have also affected the short term performance of
the method. At low flow rates, many different errors may be introduced. 相似文献
14.
Studies were performed to investigate factors affecting symptom expression of potato virus Y infection in three potato cultivars, Russet Norkotah, Shepody, and Red LaSoda. Quantitative enzyme-linked immunosorbent assay (ELISA) results revealed few differences in the relative virus titer among cultivars tested. Potato virus Y (PVY) titers developed as rapidly in Russet Norkotah as in Shepody and Red LaSoda. Additional studies were performed to determine the effect of light intensity and infections of PVY and potato virus X (PVX), alone and in combination, on the expression of mosaic symptoms in these three cultivars. Low light intensity (270-330 uE/m 2/sec) significantly increased plant heights and severity of mosaic disease among the cultivars compared to high light intensity (100-200 uE/m 2/sec). PVX and PVY, as well as the combination of PVX and PVY in the same plant, decreased plant height compared to the uninoculated (healthy) controls. Low light intensity and dual infections of PVX and PVY significantly increased mosaic disease severity in Shepody and Red LaSoda, but not in Russet Norkotah. Results of these studies refute the suggestion that Russet Norkotah is resistant to PVY infection since virus titers in this cultivar are similar to the known susceptible cultivars Shepody and Red LaSoda. These results further suggest that while Russet Norkotah is fully susceptible to infection by PVY, it resists symptom expression. 相似文献
16.
Three potato cultivars differing in degree of susceptibility to early blight were grown under crop management practices typical for Pennsylvania in 1987 and 1988. There were three experimental treatments: no fungicides, mancozeb with weekly applications initiated at 7 or 8 weeks after planting (early treatment), and weekly applications initiated at first symptoms of disease (late treatment). The no-fungicide control treatment had significantly higher AUDPC values than either treatment with fungicides and the no-fungicide treatment had significantly lower yield in 1987 but not in 1988. Tubers from the no-fungicide control had lower specific gravity. Norchip, the cultivar most susceptible to early blight examined in this study, responded the most in yield increases by the increased fungicide applications. 相似文献
17.
The response to irrigation of three parental potato cultivars was studied on loam and sandy soils by use of the line source sprinkler technique, which provided a continuous irrigation variable from 0 to 100% or more replacement of estimated evapotranspiration (Et). Solid-set sprinkler irrigation from planting until near full ground cover provided optimal early plant growth and a soil profile filled with water when the irrigation variable was started in July. On the loam soil this residual soil water provided most of the water needs of the three cultivars over a 10–12 week period until harvest. On this soil, irrigation levels providing replacement above 20 to 40% Et had little beneficial effect. In fact, higher irrigation levels had serious deleterious effects, especially on grade and solids of Nooksack. On the loam soil, Nooksack performed best in every regard at deficit irrigation levels below 50% Et. In contrast, on this loam soil, differing irrigation levels had very little effect on the productivity of Lemhi. The response of all cultivars on sandy soil was much different than on loam soil. On sand, total and U.S. No. 1 yield of all cultivars increased greatly as irrigation levels increased, up to 70 to 80% Et. Levels above this had minimal effect. Nooksack again performed better than the other two cultivars under deficit irrigation. The results of these and other studies show there is potential for identifying or developing potato cultivars which are more efficient users of irrigation water. 相似文献
18.
Fifty-one potato cultivars were evaluated for reaction to infection by Pseudomonas solanacearum Sm. under high disease pressure in a field plot near Tifton, Georgia during the spring of 1978 and 1979. Plots were infested by clipping beds of thickly seeded tomato plants with a rotary mower contaminated with the wilt baterium in 1975, 1976, 1977 and 1978. The plants were incorporated into the soil following disease development. In addition to the use of infested soil, one stem on each potato plant was inoculated in late May by cutting with a knife blade dipped in a bacterial suspension. Most of the cultivars evaluated were highly susceptible to bacterial wilt. Ontario was the only cultivar highly resistant to the disease, with only 1% and 8% dead or dying plants in 1978 and 1979, respectively. Based on tuber infection, Ontario and Snowchip were the most resistant, with 9% and 14% infection, respectively, in 1978 and both 4% in 1979. Saco, Green Mountain and Sebago also showed some resistance. 相似文献
19.
Greenhouse and field studies were conducted to evaluate the susceptibility of six potato ( Solatium tuberosum L.) cultivars to injury by four herbicides. The White Rose cultivar was the most susceptible to injury, especially from metribuzin {4-amino-6- tert-butyl-3-(methylthio)- s-triazin-55 (4H) one}, and linuron {3-(3,4-dichlorophenyl)-l-methoxy-l-methyl-urea}. Injury was attenuated by decreasing the rate of herbicide in the range of 4.5 to 0.5 kg/ha (4 to 0.5 1b/A) and by increasing the seed piece size. Injury seemed to be associated with soil texture and was greater in a sandy loam than in a sandy clay loam soil. Greenhouse studies provided valuable leads on cultivar susceptibility to herbicides but reductions in foliar weight of 15 to 20% are required to justify any suspicion that field injury will occur. 相似文献
|