Movement of fluometuron, simazine, ³⁶Cl⁻ and ¹⁴⁴Ce³⁺ in soil under field conditions: qualitative aspects     

R.J. HANCE  S.J. EMBLING  D. HILL†  I.J. GRAHAM-BRYCE§  P. NICHOLLS‡ 《Weed Research》1981,21(6):289-297

The distributions of two herbicides and two radioactive ions in field plots at two sites were determined at periods up to 187 days following surface applications in the spring. The results demonstrated the variability characteristic of field situations. At one site some fluometuron moved a short distance down the profile but after 187 days most remained above 6 cm whereas at the other site there was essentially no movement below 3 cm. At both sites simazine was almost entirely confined to the top 3 cm. The adsorption characteristics of the two compounds are similar so the greater mobility of fluometuron is probably a consequence of its greater solubility, Measurements of ³⁶Cl^? indicated a significant movement of water through the 30 cm depth studied. ¹⁴⁴Ce³⁺ used as a tracer of soil particles was of similar mobility to simazine. In general the movement of chloride and the two herbicides can be interpreted in terms of the concept of mobile and immobile fractions of soil water in which a proportion of the mobile water does not reach equilibrium with solutes in the bulk of the soil. Soil structural effects may therefore be more important than adsorption in controlling the movement of solutes and redistribution in association with soil particles can be significant. A parallel laboratory experiment showed that the results from a standard leaching column procedure did not necessarily indicate field performance.  相似文献   

Diplodia maydis²     

《EPPO Bulletin》1982,12(1):49-53

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Droplet Formation and Deposition¹     

E.J. BALS 《EPPO Bulletin》1983,13(3):357-361

At the EPPO Conference in Belgrade on 1970 the author reported on work showing that small, uniform, and non-volatile droplets appeared to offer the prospect for greatly reduced dosages of pesticides by both providing a more effective deposit and by controlling drift. Three recent studies provide further evidence for this hypothesis, which questions the very principles on which our present spraying practices are based. However, the deposition of droplets by the external forces of wind and gravity imposes lower limits on the droplet sizes capable of being used. These are 30 μm for insecticides and fungicides (except in the case of flying insects) and 150 μm for herbicides, since the droplets require sufficient energy to impact themselves on the target. Electrostatic charging of droplets promises to free us from these size constraints by providing the droplet with a depositional force of its own, allowing it to impact on any surface. Electrostatics, however, is solely a force of deposition and thus must be balanced with the forces required for spray dispersion so that the droplets can penetrate the crop canopy and/or be transported to the target  相似文献   

Mycological Diagnostic Problems¹     

G.H. BOEREMA  H.A. VAN KESTEREN 《EPPO Bulletin》1981,11(2):113-118

In diagnostics we are constantly confronted with the gaps that exist in our knowledge of the pathogenic fungal flora. This situation is illustrated by recent information concerning various economically important fungal diseases. Where such problems arise it is only through international cooperation in diagnostic mycology that they can be efficiently tackled and solved. It appears that with increasing frequency the exact identification and differentiation of fungi is only made possible through familiarity with their growth characteristics in culture. Fungus culture collections can here play an important role, since exact comparison and identification is made possible. Such pathogenic fungi should be made available for diagnostic purposes under the auspices of the Plant Protection Services, so that the risk of unwanted spreading of these pathogens can be avoided. The Plant Protection Services would in fact become more effective in their attempts to prevent and limit the distribution of harmful organisms.  相似文献   

Multiplication of some South American and European Populations of Potato Cyst Nematodes on Potatoes Possessing the Resistance Genes H₁, H₂ and H₃     

J. FRANCO  K. EVANS 《Plant pathology》1978,27(1):1-6

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Movement of fluometuron and ³⁶Cl⁻ in soil under field conditions: computer simulations     

I.J. GRAHAM-BRYCE  P.H. NICHOLLS†  R.J. BAKER†  R.J. HANCE‡  S.J. EMBLING‡  D. HILL§ 《Weed Research》1982,22(5):271-283

The movement of chloride ion and the movement and degradation of fluometuron in two soils of contrasting texture and structure was predicted with a simulation model which included terms for the degradation of fluometuron as a function of temperature and moisture. The simulated distributions of soil water, chloride ion and fluometuron were compared with the observations reported in a previous paper (Hance, Embling, Hill, Graham-Boyce & Nicholls, 1981), Soil waler contents and fluometuron distribution were simulated reasonably accurately. Movement of chloride to below 30 cm in both soils and degradation of fluometuron in the WRO sandy loam soil were not well simulated. The discrepancies between observed and predicted water contents and chloride distribution show the importance of measuring dynamic as well as static water properties. Therefore refined simulation models may need to account for pore continuity, soil particle movement and mobile and immobile categories of water.  相似文献   

Fireblight monitoring in Lithuania¹     

L. Baranauskait&#; 《EPPO Bulletin》2004,34(3):335-337

Lithuania has requested that its whole territory should be recognized by the EU as a protected zone for Erwinia amylovora . Fireblight monitoring was performed in 1998/2002 with the aim of detecting and identifying the bacterium, and of determining its distribution in the country. The study consisted of periodic surveys (at least twice a year) of nurseries, orchards, collective farms and host plants, growing individually or in small groups, as well as the surrounding zone within a radius of 250 m. Tests, under conditions of quality control, were applied to host plants with and without symptoms, using detection methods such as ELISA and immunofluorescence (with polyclonal antibodies), semi-selective plating and pathogenicity.  相似文献   

High Performance Self-Propelled Sprayers¹     

AFRANG 《EPPO Bulletin》1983,13(3):505-508

Self-propelled sprayers, which are the result of recent technological advances in farm machinery for crop protection, combine the advantages of ground equipment and airborne spraying appliances: a work rate of 100 ha per day can be achieved under comfortable working conditions, their ease of handling makes it possible to work at short notice and at almost any time of the year. Labour costs are reduced, and effective treatment can be guaranteed. This is the main economic justification of the use of these machines which, in view of their relatively high purchase cost, are suitable for farms of at least 300-400 ha.  相似文献   

Wheat Diseases in Turkey¹     

S. IREN 《EPPO Bulletin》1981,11(2):47-52

Cereal crop production is one of the most important projects in the agricultural improvement programme for Turkey. Overall, wheat represents 61 % of the cereal crop. While wheat production was almost 4 million tons in 1950, this reached a limit of 10 million tons in 1970. A number of diseases continue to afflict the crop from time to time, causing heavy losses. The most important of these are: bunt ( Tilletia foetida and T. caries ), loose smut ( Ustilago nuda ), rusts ( Puccinia strilformis, P. graminis f. sp. tritici, P. recondita f. sp. tritici ), leaf blotch ( Septoria tritici ), root and foot rots ( Fusarium spp., Drechslera sorokiniana, Pseudocercosporella herpotrichoides, Alternarla alternate, Sclerotium spp. and Rhizoctonia spp.). The diseases appear all over the country. Average losses due to rusts in epidemics are estimated at about 30–35 % in the whole country. Annual losses from covered smut are about 15–20 %, and from loose smut from 0.1 % to almost 20 % depending on the weather conditions of the year, on variety and on locality. Root rots have gained importance in some places, especially in Thrace in the last few years. In addition to the above diseases, several others occur occasionally but are of minor importance: powdery mildew ( Erysiphe graminis f. sp. tritici ), dwarf smut ( Tilletia contraversa ), flag smut ( Urocystis tritici ), take-all ( Gaeumannomyces graminis ) and a wheat mosaic virus (recently observed in a province of Central Anatolia).  相似文献   

Comparative analysis of early H₂O₂ accumulation in compatible and incompatible wheat–powdery mildew interactions     

A. L. Li  M. L. Wang ‡  R. H. Zhou  X. Y. Kong  N. X. Huo  W. S. Wang  J. Z. Jia † 《Plant pathology》2005,54(3):308-316

Comparative analysis was carried out for hydrogen peroxide (H₂O₂) accumulation in response to powdery mildew (Blumeria graminis[Erysiphe graminis] f.sp. tritici) primary germ tube (PGT) and appressorial germ tube (AGT) contact, and in papilla (cell wall apposition) and hypersensitive responses (HR) in wheat (Triticum aestivum). Using primary leaves of three susceptible wheat lines (Bainong 3217; Beijing 837; Jingshuang 16) and five resistant lines [Mardler (Pm2 + Pm6); Ulka/8 × Cc (Pm2); Mardler/7 × Bainong 3217 (Pm2); Pm16; Pm16/7 × Beijing 837 (Pm16)], early H₂O₂ accumulation between 10 and 48 h after inoculation was studied. Strong H₂O₂ accumulation was found in effective papillae and associated cytosolic vesicles in both susceptible and resistant wheat lines, suggesting the important role of H₂O₂ in effective papillae formed as a general plant defence against powdery mildew. High frequency of effective papilla formation was observed in all five resistant lines. Among resistant lines, hypersensitive cell death was detected earlier in Mardler and Ulka/8 × Cc than in Pm16 and Pm16/7 × Beijing 837. In all cases this was associated with H₂O₂ accumulation in attacked epidermal cells. Interestingly, penetration resistance but not HR appeared to be mediated by the Pm2 gene in the Mardler/7 × Bainong 3217 line, suggesting that Pm2 may govern an HR-independent defence pathway in this genetic background. As effective papillae and HR did not occur in the same cells, papilla deposition may be independent of the HR response, despite the fact that both defence mechanisms were associated with high H₂O₂ accumulation. In wheat powdery mildew-incompatible interactions, HR acts as a second line of defence to contain infection when the papilla defence fails.  相似文献   

The uptake and translocation of ¹⁴C-SAN-6706 and ¹⁴C-SAN-9789 in Vaccinium macrocarpon cv. Early Black     

ROBERTW. YAKLICH  STANISLAW J. KARCZMARCZYK†  ROBERT M. DEVLIN‡ 《Weed Research》1974,14(4):261-263

The uptake and translocation of ¹⁴C-labelled 4-chloro-5-(dimethytamino)-2-(α,α,α,-trifluoro-m-lolyl)-3(2H)-pyridazinone (SAN-6706) and 4-chloro-5-(melhylamino)-2-(α,α,α,-trifluoro-m-tolyt)-3(2H)-pyridazinone (SAN-9789) were studied in cranberry plants (Vaccinium macrocarpon Ait. cv. EarlyBlack). The plants were treated in water solution and sampled at 1,3,8 and 15 days. Other plants were treated for these times, washed free from extraneous herbicide, grown for 3 weeks longer in nutrient with no herbicide and then sampled to determine the fate of the herbicide. Both compounds were readily translocated and the amount of label present in the shoot increased with time. In plants grown for 3 more weeks after treatment there was translocation of the label from the root to the shoot. No radioactive label was detected in the cranberry fruit. Absorption et migration du ¹⁴C-SAN-6706 et du ¹⁴C-SAN-9789 chezVaccinium macrocarpon cv. Early Black L'absorption et la migration de la 4-chloro-5-(dimeAthyiamino)-2-(α,α,α-trifluoro-m-tolyl)-3(2H)-pyridazinone (SAN-6706) et de la 4-chloro-5-(méthylamino)-2-(α,α,α-trifluoro-m-tolyl)-3(2H) pyridazinone (SAN 9789), marquées au ¹⁴C, ont été eAtudiées chez la canneberge (Vaccinium macrocarponAit, cv. Early Black). Les plantes ont été traitées en solution aqueuse et échantillonnfées aprés 1, 3, 8 et 15 jours. D'autres plantes ont éteA traitées pour ces mêmes durées, Iavées pour éliminer les traces externes d'herbicide, et cultivées pendant 3 semaines de plus en milieu nutritif sans herbicide, et enfin échantillonnées pour determiner le devenir de L'herbicide. Les deux composes migrerent rapldement et la quantité de produit marqué présente dans la partie adrienne augmenta avec le temps. Dans les plantes cultivées 3 semaines supplémentaires aprés le traitement, il y eut migration du produit marque des racines vers les tiges. Aucun élément radioactif n'a été décelé dans les fruits de canneberge. Die Aufnahme und Translokatlon von ¹⁴C-SAN-6706 und¹⁴CSAN-9789 bei Vaccinium macrocarpon Sorte Early Black Es wurde die Aufnahme und Translokation von ¹⁴C-markiertem 4-Chlor-5-(dlmcthylamino)-2-(α,α,α;-trifluor-m-tolyl)-3(2H)-pyridazinon (SAN-6706) und 4-Chlor-5-(methylamino)-2-(α,α,α-trifluor-m-tolyl)-3(2H)-pyridazinon (SAN-9789) bei Preiselbeerpflanzen (Vaccinium macrocarpon Ait. Sorte Early Black) untersucht. Die Pflanzen wurden in Wasserkultur behandelt und nach 1, 3, 8 und 15 Tagen Proben genommen. Bei anderen Pflanzen, die auch über diese Perioden behandelt worden waren, wurde anschliessend das äuβerlich anhaftende Herbizid abgewaschen, für 3 weitere Wochen in NaUhrlösung ohnc Herbizid gehalten und dann Proben gezogen, um die Verteilung des Herbizids zu bestimmen. Beide Verbindungen wurden rasch transloziert und der Gehait an markierter Substanz im Spross nahm mit der Zeit zu, in den Pflanzen die für 3 weitere Wochen nach der Behandlung gewachsen waren, wurde Translokation voti der Wurzel in den Spross festgestellt. In der Preiselbeerfrucht konnte keine Radioaktivität festgestellt werden.  相似文献   

New Techniques in Seed Treatments¹     

A.M. TOMS 《EPPO Bulletin》1983,13(3):471-474

The paper deals with the treatment of seeds other than cereals and describes the technique of seed coating with the incorporation of the required pesticides. The formulation of the pesticides has to be modified for this technique. The advantages of seed coating are given and include the increased loading of chemicals onto seeds, thereby increasing the diseases and pests that can be controlled by the coating technique.  相似文献   

International Cooperation in Plant Protection¹     

H. RØNde Kristensen 《EPPO Bulletin》1984,14(3):429-438

Preventing the introduction of dangerous organisms into new countries and regions requires an international approach. The article reviews the most dangerous organisms for different continents, and describes in particular the procedures developed in Europe for assessing quarantine risks, through international cooperation within the European and Mediterranean Plant Protection Organization. The activities of EPPO are reviewed, and also those of the ISHS Plant Protection Commission, especially in relation to fruit-tree viruses. The implementation of international cooperation within the European Community, and specifically in Denmark, is described.  相似文献   

Electrostatic Application with Rotary Atomisers¹     

A.J. ARNOLD 《EPPO Bulletin》1983,13(3):451-456

The APE80 charged rotary atomiser, and its larger, JUMBO, counterpart, both developed at Rothamsted, are briefly described. Recent design modifications allow control of the trajectory and subsequent distribution of the spray. Some field results illustrate the increase in deposition obtained with charged sprays and the effect on spray penetration.  相似文献   

Analyzing Cost Effectiveness of EPIPRE¹     

J.C. Zadoks 《EPPO Bulletin》1984,14(3):401-407

EPIPRE is an integrated pest and disease management system for wheat, fully computerized, based on on-line calculations of costs and benefits of pesticide treatments; it is field-specific and utilizes disease and pest monitoring in the field. The development of the project took five years (1977/1981). Cost effectiveness has been estimated in retrospect and in prospect using 1980 as a base year, covering the period 1977 through 1985. Future costs were disccrunted at a 10 % rate. The Net Present Worth of the project was estimated at nearly eight million Dutch guilders. The nonmeasurable effects of the project seem to be even more important than the measurable effect.  相似文献   

Grey Mould Damage and Control in Hungary¹     

B. TOTH 《EPPO Bulletin》1982,12(2):105-107

Grey mould is one of the most important fungal diseases of grapevine, and for this reason the successful control of Botrytis cinerea determines the result of grape growing. As far as damage is concerned, the most important infection occurs at the end of flowering and just before ripening. The conidia of the fungus infect the berries through wounds, which may be caused by hail or storms, or by chewing insects, or also, most importantly, by physiological berry splitting. This occurs when a long dry period in summer is followed by a rainy autumn at ripening time. The prevention of wounds is one of the most important aspects of control. For the first half of the year, we propose using the traditional contact fungicides against grey mould. The use of benzimidazole-type systemic fungicides is proposed only for the last two treatments, because they have a low persistence and because in this way we avoid the development of resistance to these systemic fungicides.  相似文献   

Maize Pests and their Importance in Turkey¹     

N. LODOS 《EPPO Bulletin》1981,11(2):87-89

Maize and related crops suffer from a large number of insect pests in Turkey but all are not of the same importance in different parts of the country. This paper lists about 80 species, of which only a few ( Sesamia nonagrioides, Helicoverpa armigera, Ostrinia nubilalis , cutworms ( Agrotis spp.), Tanymecus dilaticollis, Gryllotalpa gryllotalpa ) are of primary importance. The pest status and distribution of each species is described.  相似文献   

Uptake patterns of soil-applied ⁴⁵Ca and ³²P in some legume species as influenced by differential trifluralin placement     

J. T. O'DONOVAN  G. N. PRENDEVILLE 《Weed Research》1977,17(5):311-314

The effect of localized placement of trifluralin on uptake patterns of soil-applied ⁴⁵Ca in vetch (Vicia sativa L.), pea (Pisum sativum L.) and soybean (Glycine max) and ³²P in vetch and pea was investigated in two soil zones in the roots and in the shoot zone before and after plant emergence. When trifluralin was in the upper root zone severe inhibition of lateral roots occurred as well as a marked decrease in uptake of ⁴⁵Ca and ³²P from this zone. Root growth in the lower zone was unaffected, but uptake of ⁴⁵Ca and ³²P was slightly reduced. Compensatory adventitious root growth as well as a marked increase in uptake of ⁴⁵Ca and ³²P occurred in the shoot zone. Neither root growth nor uptake of ⁴⁵Ca or ³²P in the upper root zone were affected by the presence of trifluralin in the lower root region. When trifluralin was placed in the shoot zone after plant emergence, adven-titious roots on the shoots were inhibited and uptake of ⁴⁵Ca and ³²P was reduced.  相似文献   

Cutting weeds with a CO₂ laser     

T Heisel  J Schou  S Christensen  & C Andreasen† 《Weed Research》2001,41(1):19-29

Stems of Chenopodium album . and Sinapis arvensis . and leaves of Lolium perenne . were cut with a CO₂ laser or with a pair of scissors. Treatments were carried out on greenhouse-grown pot plants at three different growth stages and at two heights. Plant dry matter was measured 2 to 5 weeks after treatment. The relationship between dry weight and laser energy was analysed using a non-linear dose–response regression model. The regression parameters differed significantly between the weed species. At all growth stages and heights S. arvensis was more difficult to cut with a CO₂ laser than C. album . When stems were cut below the meristems, 0.9 and 2.3 J mm⁻¹ of CO₂ laser energy dose was sufficient to reduce by 90% the biomass of C. album and S. arvensis respectively. Regrowth appeared when dicotyledonous plant stems were cut above meristems, indicating that it is important to cut close to the soil surface to obtain a significant effect. When cutting L. perenne plants with 2-true leaves at a height of 2 cm from the soil surface with a laser, the biomass decreased significantly compared with plants cut by scissors, indicating a delay in regrowth. This delay was not observed for the dicotyledonous plants nor for the other growth stages of L. perenne .  相似文献   

The application of picloram-¹⁴C to bracken     

J. FARNWORTH  G. M. DAVIES 《Weed Research》1974,14(6):397-399

Experimental systems were produced from fragments of bracken rhizome and picloram-¹⁴C was applied to frond laminae, rhizome apices, frond buds and roots and translocation assessed 7 days after treatment. The isotope was readily taken up by all organs and freely translocated to associated fractions of the rhizome except in the case of laminae from which distribution was very poor. Accumulation of activity in the roots was considerable following treatment of the frond buds but was limited in the frond buds. Poor translocation of herbicide from treated frond laminae is considered a possible explanation of poor control in the field when bracken is sprayed in July. Lapplication du picioram e¹⁴C à la fougère Des systèmes expérimentaux ont étéétablis en utilisant des fragments de rhizome de fougére et du piciorame ¹⁴C a été appliqué sur les limbes des frondes, les apex des rhizomes, les bourgeons des frondes et les racines. La migration fut évaluée sept jours aprés le traitement. L'isotope a été facilement absorbé par tous les organes et librement transporté aux fractions correspondantes du rhizome, sauf dans le cas des limbes è partir desquels la distribution a été très faible. L'accumulation de ractivité dans les racines a été considérable è la suite du traitement des bourgeons de frondes mais a été Iimitée dans les bourgeons de frondes. Une faible migration de I'herbicide depuis les limbes des frondes est considérée comme une explication possible du désherbage mediocre auchamp, lorsque la fougère est traitée en juillet. Die Anwendung von PicIoram-¹⁴C zu Adlerfarn Aus Rhizomstücken von Adlerfarn wurden Versuchsp-flanzen gezogen und auf die Wedelspreiten, Rhizomapices, Wedelknospen und Wurzein- Picloram-¹⁴C appliziert. Die Transiokation des Herbizids wurde eine Woche nach der Behandlung gemessen. Das lsotop wurde von alien Pflan-zenorganen schnell aufgenommen und in die dem Rhizom benachbarten Pflanzenteile transloziert; bei Behandlung der Wedelspreiten war jedoch nur eine geringe Verteilung fest-zustellen. Nach Behandlung der Wedelknospen war in den Wurzein eine beträchtliche, aber in den Wedelknospen nur eine geringe Aktivitätsanreicherung feststellbar. Für den schwachen Bekämpfungserfolg des Adierfarns im Freiland bei Spritzungen im Juli, wird die geringe Transiokation des Herbizids aus den Wedelspreiten als mögliche Erklärung angesehen.  相似文献