Prediction of codling moth egg hatch in Germany and Italy using the Californian forecasting model Bugoff21     

N. BLAGO  E. DE BERARDINIS 《EPPO Bulletin》1991,21(3):407-414

The effectiveness of the Californian model Bugoff2 for Cydia pomonella was tested in Germany (4 years) and Italy (2 years), the Italian results confirming the German findings. In the first codling moth generation (air temperatures normally below 30 C) good agreement was found between field observations of egg hatching and the model's forecast. However, the model gave notable differences for the second generation, i.e. 3 weeks in Germany and 1 week in Italy, and a significant difference for the third generation in Italy. These divergencies arise from an overestimation of the development rate of the codling moth in Bugoff 2's heat unit table whenever air temperature exceeds the upper limit for development. As a result of modifications to Bugoff 2, an example of a better simulation of the codling moth egg hatch in Germany and Italy is discussed.  相似文献   

Abstracts of papers presented at the second otto warburg symposim on biotechnology: plant - microorganism interaction in the rhizosphere     

A. HüTtermann Marie-Therese Oelbe  E. Fritz  G. Schlechte  A. Bytom  A. D. Jungk  Y. Okon  E. Fallik  Rivka Hadas  S. Sarig  E. Yahalom  Sara Tal  A. Hartmann  B. Kishinevsky  Debora Gurfel  Rina Lobel  Y. Kapulnik  D. A. Phillips  Y. Hadar  Y. Chen  E. Jurkevitch  J. Katan  A. Gamliel  H. Ziegler  I. Chet  A. Ordentlich  Hadar Kless  A. Oppenheim  Avia Zilberstein  D. Holland  J. Berman  A. Zamir  R. Kaufman  N. Bawnik  C. Koncz  J. Schell 《Phytoparasitica》1987,15(2):141-147

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Rhabdovirus-like particles in the sporocyst of the trematode Brachylaimus fuscatus from terrestrial mollusc Ponsadenia duplocincta     

Z Zdárská  T N Soboleva  J Weiser 《Folia parasitologica》1986,33(3):277-279

Rhabdovirus-like particles containing nucleoprotein in a helix with eight turns was demonstrated by transmission electron microscopy in subtegumental cells and syncytial layer of tegument in Brachylaimus fuscatus sporocyst. This is the first case of virus infection in trematodes. The possibility of transfer of the virus to intra-molluscan parasitic generations of the trematode is discussed with respect to the peculiarities of the life cycles of the family Brachylaimidae.  相似文献   

Some factors affecting the performance of fluazifop-butyl against Elymus repens (L.) Gould (=Agropyron repens (L.) Beauv.)     

J. P. N. R. CHANDRASENA  G. R. SAGAR 《Weed Research》1986,26(2):139-148

In this series of glasshouse experiments, several factors influencing the foliar activity of fluazifop-butyl, butyl-2-[4-(5-trifluoromethyl-2-pyridylox-y)phenoxy] propionate, against Elymus repens (L.) Gould (=Agropyron repens(L.) Beauv.) were investigated. The growth stage of the weed even up to about 16 weeks of age was not found to be a major factor affecting the performance, if a dose of 1.0 kg ai ha^?1 is used. The activity of fluazifop-butyl was affected by low temperature, low humidity and water stress, all of which reduced the herbicide performance to varying extents. High post-treatment temperature or humidity favoured the activity of the herbicide, as measured from the regrowth ability of treated plants. Moderate water stress did not affect the activity significantly, but severe stress led to the plants becoming more tolerant of the herbicide. The effect of light/shade on foliar activity was not clear, bin showed a tendency of decreasing with increasing shade. Adverse effects of rain, probably due to wash-off of the retained spray droplets, reduced the performance of fluazifop-butyl, if rain fell within 6 h of spraying. Certains facteurs qui touchent à la performance du fluazifop-butyle contre Elymus repens (L.)Gould. (= Agropyron repens (L.) Beauv.) Cette expérimentation en serre a porté sur plusieurs facteurs qui influent sur l'activité foliaire du fluazifop-butyle, butyle-2–4-(5-trifluorométhyl-2-pyridyloxy)phénoxy proprionate, contre Elymus repens (L.) Gould (Agropyron repens (L.) Beauv.). Il en résulte que, même jusqu'à l'âge de 16 semaines, le stade végétal de l'adventice ne paraît pas jouer un rôle important dans la performance de l'herbicide à une dose de 1,0 kg ma ha^?1. L'activité du fluazifop-butyle se trouve altérée en conséquence de température faibles, d'une faible humidité et de carence d'eau; tous ces facteurs ont amené une réduction plus ou moins grande dans la performance de l'herbicide. A en juger part la croissance nouvelle des plantes traitées, une température élevée, de même qu'une forte humidité suivant l'application, favorisent l'activité herbicide. La carence d'eau n'a exercé une influence significative sur l'activité herbicide que lorsqu'elle est devenue sévère; alors les plantes ont fait preuve d'une moindre tolérance. L'influence de la lumière sur l'activité foliaire est restée imprécise mais celle-ci a eu tendance à dimineur à mesure qu'augmentait l'ombre. Les effets néfastes de la pluie, grâce sans doute au lessivage des gouttelettes retenues sur les feuilles, ont diminué l'efficacité du fluazifop-butyle lors d'une précipitation moins de 6 heures après la pulvérisation. Einflüsse auf die Wirkung von Fluazifop-butyl auf Elymus repens (L.)Gould. (= Agropyron repens (L.) Beauv.) Verschiedene Einflüsse auf die Blattwirkung von Fluazifop-butyl Butyl-2-[4-(5-trifluormethyl-2-pyridiloxy)phenoxy]propionate auf die Gemeine Quecke wurden in einer Reihe von Versuchen im Gewächshaus untersucht. Das Entwicklungsstadium des Unkrauts war auch bei bis zu 16 Wochen alten Pflanzen ohne Einfluss auf die Wirkung, solange 1,0 kgAS ha^?1 angewandt wurden. Niedrige Temperatur und Luftfeuchtigkeit sowie Wassermangel setzen die Wirkung des Herbizids, die am Wiederaustrieb gemessen wurde, herab. Hohe Temperatur und Luftfeuchtigkeit nach der Behandlung begünstigten die Wirkung. Schwacher Wassermangel beeinflusste die Wirkung nicht signifikant, aber bei starkem Wassermangel waren die Pflanzen widerstandsfähiger. Die Wirkung einer Beschattung der Pflanzen auf die Wirksamkeit des Herbizids war undeutlich, aber tendenziell zeigte sich eine Abnahme der Wirkung mit Zunahme der Beschattung. Regen innerhalb 6 Stunden nach der Behandlung verminderte die Wirkung von Ftuazifop-butyl, vermutlich wegen des Abwaschens des Spritzbelags von den Blättern.  相似文献   

Application of aldicarb in a drip-irrigated cotton field for the control of the Tobacco Whitefly(Bemisia Tabaci)     

N. Aharonson  Z. Magal  Lea Muszkat  D. Tepperman  E. Goren  U. Tadmor 《Phytoparasitica》1986,14(1):87-91

Cotton was grown in loess soil, in rows 1 m apart, and drip-lines were placed in the center of every second space between rows at a distance of 50 cm from the plants. Aldicarb was applied as granules (containing 15% a.i.) to the field on two dates (mid-June and mid-July) and incorporated into the soil(a) 25 cm from the plants,i.e., equidistant from the plants and the drip-lines, on both sides of the drip-lines; and(b) 50 cm from the plants,i.e., in the center of the spaçe between the rows, near the drip-line. Measurements of mortality ofBemisia tabaci larvae, and of the accumulation of aldicarb from the late (mid-July) treatment showed that best control of the pest and the highest aldicarb residues were obtained with the late treatment. The pest control effectiveness was found to depend on both date and location of aldicarb application. Early treatment (mid-June) was more effective if applied close (25 cm distance) to the plant stems, whereas late treatment (mid-July) was more effective if applied at a distance of 50 cm from the plant stems.  相似文献   

Resurgence of Cryptodiaporthe populea in Italy1     

N. ANSELMI 《EPPO Bulletin》1986,16(3):571-583

Serious resurgence of Cryptodiapor the populea (anamorph Dothichiza populea), with appearance of perithecia, has been reported on poplar in Italy, particularly upon newly commercialized clones. Disease symptoms, incidence of attack and resulting damage have been examined through all phases of poplar cultivation, on various clones and under different environmental conditions. Consideration was also given to predisposing factors such as the water status of the plant, the adaptability to the environment of the clones and its other genetic characteristics. Levels of resistance to D. populea of 131 of the most important European clones are reported for North Italy. Most Populus deltoides and P. trichocarpa clones and their hybrids appeared resistant, while most P. nigra clones were susceptible and P. euramericana clones were partly susceptible and partly resistant. Immediate control strategies, and current genetic improvement programmes in Italy, are discussed.  相似文献   

Interactions among maize streak virus disease, leafhopper vector populations and maize cultivars in forest and savanna zones of Nigeria   总被引：1，自引：0，他引：1  

C. M. ASANZI  N. A. BOSQUE-PEREZ  I. W. BUDDENHAGEN  D. T. GORDON  L. R. NAULT 《Plant pathology》1994,43(1):145-157

Monthly plantings of three maize cultivars with differing resistance/susceptibility to maize streak geminivirus (MSV) and samplings of Cicadulina leafhopper vectors were made from December 1988 to April 1990 in the humid forest and from May to November 1989 in the Guinea savanna zones of Nigeria. High MSV disease incidences (43–56%) were recorded on susceptible cultivar TZB-Gusau in late-season (July-October) plantings. Hybrid 8321-21 showed significantly lower MSV disease incidence and severity than the other two cultivars, TZB-Gusau and 8329-15. Cicadulina species population peaks (5.2-13.5 leafhoppers/m²) were observed before the rains ended in savanna locations and after the end of the rains in the forest zone. Cicadulina mbila was the predominant species, whereas C. storeyi (syn. C. triangula ), C. arachidis, C. similis and C. ghaurii were less common. The proportion of viruliferous leafhoppers increased as the season progressed, reaching maxima of 15–25% at the end of the growing season. Interactions between disease incidence, Cicadulina populations, maize cultivars and rainfall are discussed.  相似文献   

Restriction fragment length polymorphisms (RFLPs) and the relationships of some host-adapted isolates of Verticillium dahliae   总被引：2，自引：0，他引：2  

C. A. N. OKOLI  J. H. CARDER  D. J. BARBARA 《Plant pathology》1994,43(1):33-40

The relationships of two host-adapted pathotypes of Verticillium dahliae have been examined at the molecular level using restriction fragment length polymorphisms. Isolates obtained from and adapted to Mentha × piperita (peppermint), which were presumed to be haploid, formed a distinct subspecific group (referred to as M) related to the previously described non-host-adapted subspecific group A of V. dahliae. The limited molecular variation found among the four group M isolates was not related to geographic origin. Isolates from several cruciferous hosts (and one from Beta vulgaris (sugar beet)), which are thought to be natural, stable diploids, formed another distinct group (referred to as D) that was markedly different from all previously described subspecific groupings in both V. dahliae and V. alboatrum. This group of isolates might better be regarded as a separate species. Again, only limited variation was found within the D group. Polymorphisms revealed by two probes distinguished two isolates derived from Brassica rapa (Chinese cabbage) from the six other isolates (four from Brassica napus (oilseed rape) and one each from Raphanus raphanistrum (wild radish) and Beta vulgaris).  相似文献   

Resistance to Peronospora viciae expressed as differential colony growth in two cultivars of Pisum sativum     

J. S. C. CLARK  P. T. N. SPENCER-PHILLIPS 《Plant pathology》1994,43(1):56-64

Peronospora viciae sporulated frequently following localized inoculation of leaflets of Pisum sativum cv. Krupp Pelushka but rarely on cv. Early Onward (60 and < 1% of plants respectively). Similar results were obtained following inoculation of seedling shoot apices. The proportions of sporangia that germinated, formed appressoria, invaded via stomata or cuticle, and established colonies, were similar on leaflets of both cultivars. After 2 days, total hyphal lengths of most colonies were greater than 100 μm (94% in Krupp Pelushka, 64% in Early Onward), but in Krupp Pelushka there were five times as many haustoria per unit length of hypha. Subsequently, only occasional colonies in Early Onward grew to the same extent as in Krupp Pelushka, with 8% and 88% respectively attaining lengths > 800 μm after 4 days. Reduced growth of hyphae in Early Onward was associated with increased frequency of host cells stained by trypan blue.  相似文献   

Studies on the biology of black mould (Aspergillus niger) on temperate and tropical onions. 1. A comparison of sources of the disease in temperate and tropical field crops     

N. J. HAYDEN  R. B. MAUDE  F. J. PROCTOR† 《Plant pathology》1994,43(3):562-569

Aspergillus niger colonies were present on 60–90% of the leaves sampled from onion crops grown under hot, tropical conditions (Shambat, Sudan), but only on 21% of leaves in crops grown under temperate conditions (Wellesbourne, UK). The seed stocks used in the Sudan were naturally contaminated with A. niger , whereas the fungus was absent from seed used in the UK. Inoculation of seed with A. niger resulted in an increase in the incidence of the fungus on onion plants (mean 83% of plants with affected leaves) in the field and on bulbs in store in crops grown in the UK. In the UK, A. niger is infrequent in the soil and air, but it is a major component of the soil and air mycoflora in the Sudan. Most of the bulbs grown in Sudan were contaminated with A. niger at harvest because of the high incidence of the fungus in the field.  相似文献