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1.
Summary Seed tubers were immersed in suspensions of thiabendazole (Storite) or thiabendazole plus imazalil (Extratect) at different
concentrations and planted in a field experiment. During the following 2 years samples of the produce were planted after treatment
with the same fungicide formulation used on the seed.
Silver scurf on daughter tubers decreased as concentrations of fungicide increased and Extratect gave better disease control
than Storite applied at the same thiabendazole concentration. Isolates ofH. solani resistant to thiabendazole were found on seed tubers 6 weeks after treatment with Storite, and also on daughter tubers after
the first application of the higher rates of Storite; their incidence increased with further annual treatments. In 3 years
no thiabendazole-resistant isolates were found after treatment with Extratect. Chlamydospores ofH. solani developed when sensitive isolates were subcultured onto agar containing thiabendazole. Isolates sensitive to thiabendazole
were slightly more sensitive to imazalil than resistant ones. 相似文献
2.
G. A. Hide 《Potato Research》1994,37(3):287-290
Summary Silver scurf on daughter tubers at harvest was decreased by treating seed tubers with imazalil or thiabendazole in March but
significantly increased when the treated tubers were wounded the day before planting in May. The disease was also increased
by wounding seed tubers not treated with fungicide. Black dot was decreased by seed treatment with imazalil but was not affected
by wounding. 相似文献
3.
Resistance to thiabendazole, sometimes of varying degrees, has occurred in a number of fungal species causing diseases of
potato tubers, including skin spot caused by Polyscytalum pustulans. The effect of applying a range of concentrations of thiabendazole, imazalil or a formulated mixture of thiabendazole and
imazalil on the development of isolates of P. pustulans partially or fully resistant to thiabendazole and on the control of skin spot over a number of successive generations of
seed potato multiplication was examined in a series of experiments over 3 years. Seed tubers were inoculated with a sensitive,
partially resistant or fully resistant isolate in the first year of an experiment and combinations of fungicide and a range
of concentrations were applied to the seed tubers annually before planting over two or three successive generations. Immersing
seed tubers inoculated with the partially resistant isolate in a relatively high concentration of thiabendazole, 0.7 g a.i.
l-1, did not result in the development of fully resistant isolates. Moreover, the effect of all fungicides in controlling eye
contamination and skin spot did not differ between partially and fully resistant isolates. For seed tubers inoculated with
the sensitive isolate, applying thiabendazole resulted in the occurrence of resistant isolates on first-generation daughter
tubers, but the effect of fungicide concentration on the frequency of resistant isolates, partially or fully resistant, was
inconsistent. In one experiment, the highest frequency of resistance was found at the greatest concentration, 0.4 g a.i. l-1, but, in the second experiment, the frequency was unaffected by the concentration of thiabendazole. On second-generation
daughter tubers derived from thiabendazole-treated seed tubers, virtually all isolates were resistant and the frequency of
partially and fully resistant isolates was similar to that in the first generation. Applying a mixture of thiabendazole and
imazalil to seed tubers inoculated with a sensitive isolate resulted in the development of some resistant isolates in the
first year but the frequency did not generally increase with successive applications of the mixture. A mixture of thiabendazole
and imazalil, and imazalil alone gave similar control of eye contamination when applied at equivalent concentrations. However,
increasing the concentration of imazalil from 0.1 to 0.7 g imazalil l-1 did result in an increasing impairment of plant growth, but the deposits achieved within that range of concentrations were
greater than that recommended by the manufacturer. These results demonstrate that control of P. pustulans by thiabendazole, imazalil and a mixture of thiabendazole and imazalil applied at a range of concentrations was similar for
isolates partially or fully resistant to thiabendazole. 相似文献
4.
Summary Seed tubers, cv. Désirée, derived from stocks treated annually with thiabendazole were infected with thiabendazole-resistant
strains ofHelminthosporium solani andPolyscytalum pustulans. Samples of seed tubers were either untreated or immersed for 5 min in fungicide suspensions of thiabendazole, imazalil or
thiabendazole plus imazalil and planted on four farms in 1988 and 1989. After harvest, tuber samples from each treatment were
treated with thiabendazole and stored for 6 months.
Applying imazalil or thiabendazole plus imazalil to seed tubers decreased the severity of silver scurf and skin spot on stored
progeny tubers. Thiabendazole applied to seed tubers or to progeny tubers after harvest did not affect the severity of either
disease, but post-harvest treatment decreased the incidence of black scurf after storage. 相似文献
5.
The occurrence, pathogenicity (1997 isolates only) and fungicide sensitivity of pathogens causing dry tuber rots in Scottish
seed potatoes was investigated over three storage seasons between 1997 and 2000 in relation to region of production, cultivar,
class and generation of seed potatoes, type of temperature control in store and earthiness of tubers. A total of 156 samples,
each comprising up to ten rotted tubers, was received over the three seasons. The relative importance of each pathogen in
causing rots was summarised by calculating a mean rot index that combined the prevalence of a pathogen in the samples with
the incidence of tubers affected by the pathogen within those samples. Phoma foveata (gangrene) had the highest rot index, which was five times greater than for P. exigua and ten times greater than for P. eupyrena. This relationship was mirrored by the relative pathogenicities of P. foveata and P. eupyrena, as measured by size of rots developing at inoculated wounds in test tubers. Fusarium avenaceum appeared to be the greatest cause of Fusarium dry rots, having a rot index at least twice as great as that for F. solani var. coeruleum. Infection by F. sulphureum was relatively uncommon. In the pathogenicity test, F. avenaceum, F. solani var. coeruleum and F. sulphureum produced rots of similar depths and widths and larger than those of F. culmorum. The mean rot index for Cylindrocarpon spp. was slightly more than that for F. avenaceum, whereas C. destructans produced smaller rots in the tuber pathogenicity test. Region of production affected the prevalence of P. foveata and F. avenaceum, but only the occurrence of P. foveata was affected by class and generation of seed potatoes. Isolate sensitivity to thiabendazole and imazalil was examined in
vitro over 2 years. Six out of seven isolates of F. sulphureum were resistant to thiabendazole, with the remaining isolate being partially resistant. The growth of two out of 34 isolates
of F. avenaceum was inhibited by more than 50% only at 100 mg thiabendazole l−1. All isolates, except those of F. avenaceum,, were inhibited in their growth by more than 50% at either 1 or 10 mg imazalil l−1. However, the growth of 40% of isolates of F. avenaceum was inhibited only at 100 mg l−1. The various changes in pathogen prevalence and isolate sensitivity to fungicides recorded in this study highlight the need
for regular monitoring programmes to be conducted in order that disease-control strategies can remain effective. 相似文献
6.
Y. Gutter 《Crop Protection》1985,4(3):346-350
Thiabendazole and 2-aminobutane, when used as a combined treatment, show good compatibility, giving better results in the post-harvest control of green moulds of citrus fruits than treatment with either of the individual components. In addition, such a combination has a wider antifungal spectrum than each of the two components alone, is active against benzimidazole-resistant strains of Penicillium digitatum, and has the advantages of both thiabendazole and 2-aminobutane. 相似文献
7.
Summary Soil in a potato field naturally infested with black dot (Colletotrichum coccodes) was fumigated with methyl bromide at 126 g m−2 or left unfumigated. Potato seed tubers (cv. BP1) uninfected, lightly infected (1–25% surface affected), severely infected
(26–100% surface affected) and severely infected withC. coccodes but dusted with prochloraz manganese chloride as Octave 2.5% DP at 750 g per 100 kg seed were planted in fumigated and unfumigated
soil. When harvested, the incidence of black dot on the progeny of infected seed planted in unfumigated soil was twice that
of progeny in fumigated soil, with progeny of uninfected seed having a 68.5 times higher disease incidence in unfumigated
soil. Black dot on progeny tubers was reduced by pre-treatment of seed with prochloraz in fumigated soil only. With black
dot infested fields, planting disease-free seed or treating seed with fungicides would not decrease disease on progeny tubers. 相似文献
8.
Summary In October, 1970, a 35-tonne bulk of potato tubers cv.Pentland Crown, containing samples of cvsKing Edward andRedskin, was fumigated with 2-aminobutane in a bin store fitted for internal recirculation of air. After fumigation, some of the
treated samples were transferred to other 35-tonne lots along with untreated samples, for subsequent storage in different
environments.
Analysis of 2-aminobutane residues in tubers showed that even distribution had been achieved throughout the treated bulk.
Assessment of diseases after about five months' storage showed that fumigation gave excellent control of gangrene and skin
spot, and partial control of silver scurf under a wide range of environments. Compared with the marked effects of fumigation,
the influence of the different storage environments on levels of gangrene and skin spot in untreated tubers was slight.
Zusammenfassung Im Oktober 1970 wurde 2-Aminobutan-Gas mittels Luftumw?lzung in ein 35 Tonnen fassendes Lager mit Knollen der SortePentland Crown eingeführt; das Lager enthielt auch Muster der SortenKing Edward undRedskin. Nach der Begasung wurden einige der behandelten Muster in andere 35-Tonnen-Lager verbracht, wo verschiedene Lagerungsverfahren angewendet wurden (Tabelle 1). Das 2-Aminobutan wurde in einer Dosis von 200 mg/kg bei Beachtung einer Luftumw?lzung von ungef?hr 2,8 m3 min−1 Tonne−1 w?hrend ca. 50 Minuten angewendet. Darauf wurde w?hrend weiteren 2 Stunden die Luft im Lager umgew?lzt. Messungen der Gaskonzentrationen zwischen den Knollen w?hrend der Begasung zeigten, dass das 2-Aminobutan wahrscheinlich gleichm?ssig durch den Haufen verteilt war. Dies wurde durch Rückstandsanalysen best?tigt (Tabelle 2). Die Ergebnisse der Beurteilungen auf Befall mit Krankheiten nach fünfmonatiger Lagerung zeigten, dass 2-Aminobutan ein gutes Bek?mpfungsmittel gegen Phoma-Knollenf?ule (Tabelle 3) und Tüpfelfleckigkeit (Tabelle 4) war. Die Muster im begasten Haufen waren vollst?ndig frei von diesen Krankheiten, und ihr Vorkommen in den begasten Mustern, die zu andern Haufen bzw. Lagerungsverfahren gebracht wurden, war unbedeutend. Verglichen mit den ausgepr?gten Wirkungen der Begasung war der Einfluss der verschiedenen Lagerungsverfahren auf das Ausmass von Phoma-Knollenf?ule und Tüpfelfleckigkeit bei den nicht begasten Knollenmustern gering. Die Begasung reduzierte das Ausmass der Infektion mit Silberschorf (Tabelle 5), aber der Grad der Bek?mpfung war kleiner als bei Phoma-Knollenf?ule und Tüpfelfleckigkeit, besonders bei hoher Lagertemperatur und bei Kartoffeln, bei denen zur Zeit der Einlagerung des Pilz stark verbreitet war. Obwohl das R?uchermittel auf Lentizellenwucherungen und auf nich verheilte, mechanisch besch?digte Knollenstellen einen sch?dlichen Einfluss ausübte, wurde die Lagerf?higkeit der behandelten Knollen nicht beeintr?chtigt. Um jedoch das gute Ausschen der Knollen zu erhalten, wird empfohlen, die Behandlung von unreifen oder frisch besch?digten Kartoffeln zu vermeiden, da sonst Verf?rbung vorkommen kann. Es kann daraus geschlossen werden, dass 2-Aminobutan in der Praxis angewendet werden kann, um bei Pflanzgut in einem für geschlossene Luftumw?lzung eingerichteten Lagergeb?ude eine sehr gute Bek?mpfung von Phoma-Knollenf?ule und Tüpfelfleckigkeit und eine teilweise Bek?mpfung von Silberschorf zu erzielen.
Résumé En octobre 1970, on a introduit, par recirculation de l'air, du 2-aminobutane gazeux dans un tas de 35 tonnes de tubercules de la variétéPentland Crown, tas contenant également des échantillons des variétésKing Edward etRedskin. Après fumigation, quelques-uns des échantillons traités ont été transférés dans d'autres tas de 35 tonnes, auxquels différents traitements de conservation furent appliqués (tableau 1). Le 2-aminobutane fut appliqué à la dose de 200 mg/kg avec une vitesse de ventilation de 2,8 m3 min−1 tonne−1 pendant environ 50 minutes. Cette application fut suivie d'une recirculation ultérieure de l'air pendant 2 heures. Les mensurations des concentrations de gaz dans les intervalles d'air entre les tubercules durant la fumigation ont révélé une répartition probablement uniforme du 2-aminobutane au travers du tas. Ce que les analyses de résidus ont confirmé (tableau 2). Les résultats de cotation de maladies après cinq mois de conservation montrent une bonne efficacité du 2-aminobutane contre la gangrène (tableau 3) et l'oosporiose (tableau 4). Ces maladies sont réellement absentes sur les échantillons du tas fumigé, et leur présence est négligeable dans les échantillons fumigés transférés et soumis à d'autres traitements de conservation. L'action des différents traitements de conservation sur l'importance de la gangrère et de l'oosporiose chez les tubercules non fumigés est faible par comparaison avec les effects marqués de la fumigation. La fumigation réduit le niveau d'infection de gale argentée (tableau 5), mais à un degré moindre que pour la gangrène et l'oosporiose, spécialement lorsque la température de conservation est élevée et lorsque le champignon est abondant dans les tubercules au moment du remplissage des box. Bien que la substance fumigée a un effect néfaste sur les lenticelles proliférées, de même que sur les surfaces endommagées par les machines et non cicatrisées, le pouvoir de conservation des tubercules traités est sauvegardé. Toutefois, pour préserver l'aspect des tubercules, il est recommandé de ne pas traiter des tubercules non m?rs ou fra?chement endommagés, sinon des décolorations peuvent appara?tre. Les auteurs concluent que l'utilisation du 2-aminobutane peut entrer dans la pratique commerciale pour combattre efficacement la gangrène et l'oosporiose, partiellement la gale argentée, sur des plants de pomme de terre stockés dans un batiment permettant la circulation de l'air en circuit fermé.相似文献
9.
Summary The resistance to gangrene (caused byPhoma exigua var.foveata) of progenies from two hybridisation schedules involving cultivars resistant, susceptible, or of intermediate reaction to
gangrene was assessed. Two methods of sampling tubers from field-grown single-plant plots of 18 clones representing each progeny
were used: one tuber was taken from each plant, and a bulk sample of 18 tubers was selected at random from the whole progeny.
Gangrene resistance was assessed after incubating tubers which had been rolled in cornmeal-sand inoculum ofP. exigua var.foveata, and was expressed as a percentage of tubers infected. Results from the two methods of sampling correlated closely, and agreed
well with tests in a subsequent year on 10-tuber samples of each individual clone.
It is concluded that an 18-clone sample adequately represented each progeny, and that the mid-parent gangrene score satisfactorily
predicted the resistance of the resulting progeny. There are indications that susceptibility tended to be dominant. The implication
of these findings to breeding for resistance to gangrene is discussed. 相似文献
10.
Summary Survival of the pathogen causing silver scurf of potato (Helminthosporium solani) in Alberta soils was studied by evaluatingH. solani infection in the progeny ofH. solani-free nuclear seed potato tubers planted in fields where potatoes had never been grown or were grown 1, 2, 3, or 4 years previously.
Daughter tubers from all the fields developed silver scurf lesions, andH. solani was isolated from infected tubers. This is the first report of survival ofH. solani in Alberta soils. Soil-borne inoculum appears to have a role in the epidemiology of the disease and in the introduction of
the pathogen into silver scurf-free potato seed stock. Of 31 plant species tested, only potato was found to be a host ofH. solani. Most of theH. solani isolates from north central Alberta were more sensitive to thiabendazole than those from southern Alberta, where thiabendazole
is much more commonly used. 相似文献
11.
S. F. Carnegie P. T. Gans G. J. Jellis G. Little C. Logan R. L. Wastie 《Potato Research》1989,32(3):301-309
Summary Undamaged and damaged tubers of 10 cultivars were inoculated withPhoma foveata by two methods at five test centres over three years. Damaging tubers before inoculation increased the discrimination between
cultivars. While this increase was small with tubers rolled in cornmealsand cultures, it was often substantial with those
dipped in a suspension of comminuted agar cultures. Correlations between centres for the four tests were significant (P<0.05) and were highest for tubers inoculated with cornmeal-sand with or without damage. The gangrene scores of the cultivars
in the four tests were correlated (P<0.05) with their field susceptibility ratings but there was a strong interaction between cultivar reaction and year of test.
When tubers grown in Cumbria and Midlothian were tested at one centre over two years, the gangrene scores were also correlated
(P<0.05). 相似文献
12.
Summary Experiments were conducted on sandy and deep silty soils to assess the effect of physiological age of seed tubers and planting
date on the response of potatoes to nitrogen fertiliser. Nitrogen optima commonly had large standard errors which made interpretation
of the data difficult. On the sandy soil with cv. Record, early planting increased yield in two years but had no effect on
mean N optimum (303 kg ha−1, NOpt). Mean NOpt was less on the silty soil where the cv. Pentland Squire was grown, and was reduced from 273 kg ha−1 to 241 kg ha−1 when planting was delayed by 4 weeks. Physiological age had no effect on NOpt. On the sandy soil, residual soil mineral nitrogen
(RSMN) increased by 0.05 kg ha−1 per kg N fertiliser applied; on the silty soil the increase was four times as large. RSMN was larger following the late planted
crop on the silty soil in one year. 相似文献
13.
Summary Over the years 1966–80, experiments were done to compare the effectiveness of a number of fungicides and other chemical substances
for the control of the post-harvest potato tuber diseases gangrene (Phoma exigua var.foveata), dry rot (Fusarium solani var.caeruleum) and skin spot (Polyscytalum (Oospora) pustulans). Generally good control of gangrene and skin spot was achieved by fumigation with 2-aminobutane (sec-butylamine). Infection
levels with dry rot were too low for a definite conclusion to be reached. Thiabendazole mists and fog, and thiophanate-methyl
and imazalil mists did not give as good a control of gangrene as gaseous 2-aminobutane. However a mist formulation of a mixture
of thiabendazole and a salt of 2-aminobutane was as effective as gaseous 2-aminobutane against gangrene, but the formulation
proved unstable and unsuitable for general use. Although none of the materials tested controlled all diseases equally well,
there are several active fungicides whose use can be adapted to the particular needs and storage facilities of farmers and
merchants. In some cases where fungicides did not control pathogens, failure was traced to too low a residue or poor distribution
of the chemical over the tuber surface, suggesting faulty treatment or unsatisfactory methods of application.
Zusammenfassung Zwischen 1966 und 1980 wurden Versuche durchgeführt, um die Wirksamkeit bekannter Fungizide und einiger anderer chemischer Substanzen (haupts?chlich Organo-Halogenverbindungen) zur Bek?mpfung von Kartoffelknollenkrankheiten nach der Ernte, Phomaf?ule (Phoma exigua var.foveata), Trockenf?ule (Fusarium solani var.coeruleum) und Tüpfelfleckenkrankheit (Polyscytalum (Oospora) pustulans) zu prüfen. Tabelle 1 zeigt die Einzelheiten über die chemischen Behandlungen, die Rückst?nde ergaben, die Zeit zwischen der Ernte und Behandlung, der Applikationsmethode und der Dosis (Rückst?nde sind in Mengen pro ganzer Knolle ausgedrückt). Tabelle 2 zeigt die Ergebnisse für die Bek?mpfung von Phomaf?ule, Trockenf?ule und Tüpfelfleckenkrankheit bei verschiedenen Sorten. Lagerung und Behandlung folgten so weit als m?glich den handelsüblichen Verfahren. Phomaf?ule und Tüpfelfleckenkrankheit wurden im allgemeinen durch Begasung mit 2-Aminobutan gut bek?mpft, eine nicht ausreichende Infektion mit Trockenf?ule liess keine Aussage über die Wirksamkeit gegen diese Krankheit zu. Eintauchen in Dichlorophen war nicht sehr wirksam und Dichlorophennebel war unwirksam. Thiabendazolstaub und-spray, Thiophanatmethyl- und Imazalilstaub gaben im allgemeinen nicht so gute Bek?mpfungserfolge wie gasf?rmiges 2-Aminobutan. Das deutet darauf hin, dass die Rückst?nde zu niedrig waren, die Verbindungen zu wenig durch die Schale diffundierten, um die Pilze zu erreichen, wenn sie bereits tiefer eingedrungen waren und dass die Verteilung über die Knollenoberfl?che zu ungleichm?ssig war. Eine Mischung aus Thiabendazol und einem Salz von 2-Aminobutan war sehr wirksam gegen Phomaf?ule, sie erwies sich aber als nicht stabil und konnte für den Handel nicht hergestellt werden. Verschiedene flüchtige Organohalogenverbindungen und zwei andere wurden auf ihren Einfluss auf das Wachstum des Trockenf?ulepilzes in Reinkulturen geprüft, im Hinblick auf eine Mischung mit 2-Aminobutan. Sie wurden aber aus verschiedenen Gründen verworfen, unter anderem wegen fehlender Grundlagen über die Toxikologie einiger Substanzen. Es wird daraus geschlossen, dass, obwohl kein chemisches Produkt alle drei Krankheiten gut bek?mpfen kann, verschiedene aktive Fungizide verhanden sind, deren Gebrauch an bestimmte Notwendigkeiten und Lagerungsbedingungen bei Landwirten und H?ndlern angepasst werden kann. Es gibt betr?chtliche Hinweise, die Applikationsmethoden für St?ube zu verbessern, um h?here Rückst?nde zu erreichen und eine bessere Verteilung der Chemikalien über die Knollenoberfl?che.
Résumé De 1966 à 1980, des expérimentations ont été conduites pour apprécier l'efficacité d'un certain nombre de fongicides connus et d'autres substances chimiques (principalement des composés organo-halogénés) vis à vis des maladies de conservation de la pomme de terre: gangrène (Phoma exigua var. foveata), pourriture sèche (Fusarium solani var.coeruleum), et oosporiose (Polyscytalum (Oospora) pustulans). Le tableau 1 donne les détails de ces traitements chimiques: taux de résidus, période séparant la récolte du traitement, méthode d'application, dose (les données des résidus sont exprimées en poids de tubercules entiers). Le tableau 2 donne les résultats de l'efficacité vis à vis de la gangrène, de la pourriture sèche et de l'oosporiose, en utilisant différentes variétés de pommes de terre. La manutention et les traitements sont réalisés, dans la mesure du possible, dans les conditions de la pratique. En général, vis à vis de la gangrène et de l'oosporiose, une bonne efficacité était obtenue par fumigation avec le 2-aminobutane, mais l'infection était insuffisante avec la pourriture sèche pour juger de son efficacité contre cette maladie. Les trempages avec dichlorophen n'étaient pas très efficaces, et la nébulisation du dichlorophen était inefficace. Les pulvérisations et brumisations de thiabendazole, et les pulvérisations de thiophanate-méthyl et d'imazalil ne donnaient pas, en général, d'aussi bons résultats que le 2-aminobutane. Il semblerait que cela soit d? au taux de résidus trop faible, à l'impossibilité des produits de diffuser à travers l'épiderme du tubercule pour atteindre le champignon lorsqu'il est installé profondément, et à une distribution irrégulière à la surface du tubercule. Une formulation à base de thiabendazole et de sel de 2-aminobutane, appliquée en pulvérisation, était plus efficace contre la gangrène, mais la formulation était instable et n'avait p? être préparée pour une utilisation commerciale. Plusieurs organohalogénés voltatiles, et deux autres composés, étaient testés pour leur effet sur la croissance du champignon responsable de pourriture sèche, en culture pure, avec l'intention de les mélanger au 2-aminobutane; mais cela a été repoussé pour différentes raisons, en particulier pour l'insuffisance des connaissances concernant la toxicité des substances. En conclusion, bien qu'il n'y ait pas de produits chimiques qui contr?lent bien les trois maladies, il existe de nombreux fongicides actifs dont l'utilisation peut être adaptée aux besoins particuliers et ainsi faciliter la conservation chez les agriculteurs et les négociants. Un travail considérable peut être réalisé pour améliorer l'application de formulation par pulvérisation, afin d'obtenir des niveaux de résidus élevés et une meilleure distribution des produits chimiques à la surface du tubercule.相似文献
14.
W. W. Kirk A. B. da Rocha S. I. Hollosy R. Hammerschmidt P. S. Wharton 《American Journal of Potato Research》2006,83(3):223-232
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
15.
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
16.
Ulla Bång 《Potato Research》1991,34(4):429-441
Summary The incidence ofP. foveata in soil and tuber samples from field experiments often increased significantly as the harvest season progressed and temperatures
fell. Mean levels of tuber and soil infestation were significantly higher in irrigated rows compared with those artificially
sheltered from precipitation, both at normal and late harvest dates.
Soil infestation was most frequently detected within 10 cm of the parent tuber. No pycnidia were visible on the haulm, and
very few latently infected stem segments and leaves were detected using various methods.
In three out of four years, the incidence ofP. foveata in tubers after wounding was reduced by washing them gently in tap water immediately after harvest. 相似文献
17.
Ulla Bång 《Potato Research》1992,35(1):3-15
Summary In each of the five years 1978 to 1982, seed lots of cv. Bintje, variously infested byPhoma foveata Foister andFusarium solani var.coeruleum (Sacc.) Booth, as found by wound and cut tests, respectively, were planted in a series of field experiments at six sites
in Sweden. A statistically significant relationship between seed and progeny infestation was found forP. foveata each year, and in three years forF. solani.
Benomyl and thiabendazole mist treatments of seed tubers at grading in spring controlled the development of gangrene and dry
rot in treated seed tubers, but did not consistently reduce the levels ofP. foveata andF. solani infestation in progeny from treated seed tubers.
The site of cultivation markedly influenced mean levels ofP. foveata infestation, which were found to be related to temperature and rainfall during a 40 day pre-harvest period at the trail sites;
however, mean levels ofF. solani infestation were not so related. 相似文献
18.
Whole seed tubers have been reported to have performance advantages over seed tubers that have been cut, even if the cut tuber pieces are treated with a fungicide dust. For this study, whole seed tubers were compared to cut seedpieces and to cut seedpieces treated with four different commercial fungicide dusts for five consecutive seasons. A new field generation 3 Russet Burbank seed lot was used for each of the five years of this study. Both whole tubers and cut seedpieces were inoculated withFusarium spp., and the seedpieces were then treated with a fungicide dust. Inoculated and uninoculated untreated controls were also included. Emergence,Fusarium seed decay,Rhizoctonia stem canker, stem numbers, and vigor, as well as yield and grade data were obtained.Rhizoctonia stem canker in stems grown from whole seed tubers was significantly higher than in stems from seedpieces receiving fungicide treatment in several of the study years. Predicting whole seed tuber performance is difficult because performance varies more from year to year than performance of cut and treated seedpieces. Yield performance of whole seed tubers was not significantly better than cut and fungicide-treated seedpieces in any experimental year, and yield of large (over 280 g) tubers was significantly less than that recorded for two of the treatments when data from all five years were combined. This study demonstrated that untreated whole seed did not outperform cut and treated seedpieces for vigor, stem numbers, disease ratings, or yield in small plot comparisons for five consecutive seasons. 相似文献
19.
Summary Over 2 years, seed tubers or stems were inoculated withFusarium sulphureum Schlecht. (F. sambucinum Fuckel f. 6 Wollenw.) and the incidence of dry rot on daughter tubers assessed by standardised wound tests. The amount of
stem and soil inoculum was also measured in one year.
Inoculating stem bases resulted in greater concentrations of spores on the stem bases, greater soil populations at harvest
and more dry rot on tubers than inoculating the seed tuber. Overall, the incidence of dry rot and the amount of stem and soil
inoculum was similar for the three methods of haulm destruction: cutting and removing the stems, applying sulphuric acid or
applying diquat dibromide to the growing plants. 相似文献
20.
Summary TwoPythium spp. were isolated from diseased tubers exhibiting rots at harvest, in summer stores and also in refrigerated storage. Symptoms
shared features described for both pink rot caused byPhytophthora erythroseptica and leak caused byPythium spp.
The causal agents were identified asPythium aphanidermatum andP. ultimum by morphological and physiological observations and by fingerprinting using oomycete specific primers to amplify the internal
transcribed spacer (ITS1) within ribosomal DNAs. The optimum temperatures for infection were 30°C forP. aphanidermatum and 25°C forP. ultimum, corresponding to the optimum temperatures for growth in vitro. The optimum concentration for infection of tubers inoculated
by dipping in a suspension of oospores or hyphal swellings after wounding was found to be 103 reproductive organs/ml, whereas the infection threshold was 10 reproductive organs/ml. 相似文献