Reactions of potato varieties to skin spot (Oospora pustulans) infection and transmission in different soils

Summary Emergence delay and blanking caused by skin spot were shown to depend on the degree of seed infection and were intensified by heavier soil. From similarly affected seed they were significantly less withKerr’s Pink than withKing Edward, Majestic orRedskin. Growth was very similar from normal and necrotic buds ofKerr’s Pink but virtually no growth was recorded from necroticKing Edward buds, suggesting that sprout vigour influences field response to skin spot. Transmission of infection inKing Edward to stem bases, stolons and progeny tubers depended on seed infection and even minimal inoculum caused stolon and tuber infection especially in heavier soils. With severely infected seed transmission was greatly reduced in light soil. This indicates one means of reduction of disease incidence. Colonisation byOospora pustulans of stem bases and stolons probably provides inoculum multiplication centres. Maximum colonisation was detected generally in September and declined during senescence.

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Zusammenfassung Es werden erneut die Einflüsse verschiedener Grade einer Infektion von Pflanzknollen mit Tüpfelfleckigkeit (Oospora pustulans) auf das Auflaufen und die Fehlstellen aufgezeigt (Tabellen 2, 3 und 5). Versp?tetes Auflaufen und Fehlstellen kamen bei st?rkerem Befall des Saatgutes vermehrt vor, waren verst?rkt auf schwererem Boden, und bei ?hnlich stark befallenem Pflanzgut traten diese M?ngel beiKerr’s Pink signifikant weniger auf als beiKing Edward, Majestic undRedskin (Tabellen 2 und 3). Das Pflanzenwachstum aus normalen und nekrotischen Knospen vonKerr’s Pink war sehr ?hnlich, aber bei nekrotischen Knospen vonKing Edward wurde praktisch kein Wachstum festgestellt (Tabelle 4). Dies weist darauf hin, dass der Faktor Triebkraft die Reaktion der Sorten auf Tüpfelfleckigkeit im Feld beeinflusst. Die Krankheitsübertragung auf die Tochterknollen wurde sowohl durch die Pflanzgutinfektion als auch durch die Bodenart (Tabellen 6, 7 und 8) beeinflusst. Die Uebertragung der Krankheit bei der SorteKing Edward auf die Stengelbasen und die Stolonen sowie auf die Tochterknollen wurde untersucht (Abb. 1, 2 und 3 und Tabelle 9). Selbst die kleinste Menge Inokulum auf anscheinend freiem Pflanzgut verursachte sowohl eine Stolonen- als auch eine Knolleninfektion, besonders in schwereren Bodenarten. Anderseits übertrug stark infiziertes Pflanzgut in leichtem Boden die Krankheit nur in sehr reduziertem Masse auf die Tochterknollen. Dies würde auf eine M?glichkeit zur Bek?mpfung der Krankheit bei anf?lligen Sorten hinweisen. Starke Pflanzgutinfektion übertr?gt die Krankheit wenig mehr als ein schwacher Befall des Pflanzgutes, und wahrscheinlich müssen Stolonen und Stengelbasen als Inokulum-Vermehrungszentren betrachtet werden. Die Besiedlung der Stengelbasen und der Stolonen war im Juli (Abb. 1), 6 Wochen nach der Pflanzung, ziemlich ausgedehnt, stieg zu einem Maximum, in den meisten F?llen im September, an (Abb. 2) und nahm besonders in leichteren B?den ab, wenn die Pflanzen abzusterben begannen (Abb. 3).

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Résumé Les effets de divers degrés d’infection des plants de pomme de terre par l’oosporiose (Oospora pustulans) sur la levée et les vides sont à nouveau mis en évidence (tableaux 2, 3 et 5). De hauts niveaux d’infection des plants accroissent le retard de la levée et l’importance des ‘non-levée’; les sols lourds intensifient ces accidents; les plants étant infectés au même degré, ces accidents sont significativement moindres chezKerr’s Pink que chezKing Edward, Majestic etRedskin (tableaux 2 et 3). ChezKerr’s Pink les germes normaux et les germes nécrotiques donnent une croissance très semblable; par contre chezKing Edward, les germes nécrotiques ne donnent pratiquement aucune croissance (tableau 4). Ceci fait supposer que le facteur ‘vigueur des germes’ influence la réaction au champ des variétés à l’oosporiose. La transmission de la maladie aux tuberculesfils est également influencée par l’infection des plants et par le type de sol (tableaux 6, 7 et 8). Les auteurs ont étudié, chez la variétéKing Edward, la transmission de l’infection à la base des tiges et aux stolons, ainsi qu’aux tuberculesfils (fig. 1, 2, 3 et tableau 9); un minimum d’inoculum sur des plants apparemment sains provoque une infection à la fois des stolons et des tubercules, particulièrement dans les sols lourds. Par contre, en sol léger, des plants sévèrement infectés ne transmettent l’infection à la descendance que dans une mesure très faible. Cette observation suggère une méthode de lutte contre la maladie pour les variétés susceptibles. Une grave infection des plants transmet un peu plus l’infection qu’une infection légère et, vraisemblablement, les stolons et la base des tiges constituent des centres de multiplication de l’inoculum. La conlonisation de la base des tiges et des stolons est très importante en juillet (fig. 1), 6 semaines après la plantation, et atteint son maximum dans la majorité des cas en septembre (fig. 2), ensuite diminue, particulièrement en sols légers, au moment où les plantes vieillissent. (fig. 3).

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Edinburgh School of Agriculture Miscellaneous Publication No. 509.     

The relationship between temperature and sprout growth in stored seed potatoes

Summary Sprout growth in a range of European cultivars was studied over two seasons at constant temperatures from 2 to 25°C, with an additional 33 (day)/22°C (night) treatment in the second season. There were only minor differences in the response of the cultivars and the optimum for sprout growth was at 15–18°C in all cases, when measured over an extended period, but initially sprout growth was more rapid at 23–25°C. Sprout growth at 23–25°C was frequently arrested by sub-apical necrosis, and at these temperatures the sprouts remained short enough for the tubers to be planted by hand without desprouting.     

Cd, Ni, Pb, and Zn Concentrations in Forest Vegetation and Soils in Maine

Bioaccumulation of trace metals in plant tissues can present a health risk to wildlife, and potentially to humans. The Passamaquoddy tribe in Maine was concerned about health risks of cadmium (Cd) because of a health advisory for moose liver and kidney consumption due to high Cd levels. This study found relatively low to moderate concentrations of Cd, nickel (Ni), lead (Pb), and zinc (Zn) concentrations in four common terrestrial moose browse species, associated forest soils, and two species of aquatic vegetation on Passamaquoddy tribal land in eastern Maine. Terrestrial plant tissue concentrations ranged from 0.1 to 1.97, 0.65 to 7.08, 0.29 to 2.0, and 42 to 431 mg kg^?1 for Cd, Ni, Pb and Zn, respectively. Deciduous species, particularly aspen and birch, may be a more significant source of Cd and Zn to wildlife compared to coniferous or aquatic species. Aquatic plant tissue concentrations ranged from 0.11 to 0.14, 0.46 to 1.01, 0.8 to 0.9, and 22 to 41 mg kg^?1 for Cd, Ni, Pb and Zn, respectively. Total O horizon concentration means for coniferous and deciduous were 0.50 and 1.00, 4.27 and 4.11, 55 and 21, and 55 and 167 mg kg^?1 for Cd, Ni, Pb and Zn, respectively. The study provides baseline vegetation and soil trace metal concentrations for a remote region in Maine impacted by non-point sources.     

Shadow Europe: Alternative European Financial Geographies

ABSTRACT This paper sets out to trace some major points of convergence between an emerging literature on the political geographies of corruption¹ and current attempts to develop a renewed research agenda in the geographies of global finance—in this case in a specifically European context. In particular, we offer some preliminary observations on the need to elaborate an alternative geography of Europe's financial architecture that could incorporate the role of flows of illegal and informal finance as major driving forces behind the way in which that architecture currently constitutes itself. This is an inherently complex task due to the intrinsically hidden nature of these flows and the difficulties involved in their accurate measurement; nevertheless, they are too important to be ignored, as is too frequently the case at present. In the paper we offer some necessarily preliminary, and deliberately provocative, reflections on how to take forward such a re‐conceptualisation. Ultimately, our analysis revolves around the identification of an uneasy tension between the demand for deregulated financial markets and the increasing integration of those markets, and the international momentum towards finding ways of dealing with the (apparently) ever‐increasing problems of corruption, money laundering, and the financing of terrorism through new forms of financial regulation and control.     

Oxygen reservoirs in the early solar nebula inferred from an allende CAI

Ultraviolet laser microprobe analyses of a calcium-aluminum-rich inclusion (CAI) from the Allende meteorite suggest that a line with a slope of exactly 1.00 on a plot of delta17O against delta18O represents the primitive oxygen isotope reservoir of the early solar nebula. Most meteorites are enriched in 17O and 18O relative to this line, and their oxygen isotope ratios can be explained by mass fractionation or isotope exchange initiating from the primitive reservoir. These data establish a link between the oxygen isotopic composition of the abundant ordinary chondrites and the primitive 16O-rich component of CAIs.     

Rumen fermentation, microbial protein synthesis, and nutrient flow to the omasum in cattle offered corn silage, grass silage, or whole-crop wheat

The objectives of this study were to determine the relative effect of feeding corn silage (CS), fermented whole-crop wheat (FWCW), and urea-treated processed whole-crop wheat (UPWCW) compared with grass silage (GS), each supplemented with concentrates, on forage intake, ruminal fermentation, microbial protein synthesis, some plasma metabolites, and ruminal and total tract digestibility in cattle. Four ruminally fistulated steers with a mean BW of 509 kg (SD 6.3) were used in a 4 x 4 Latin square-designed experiment with each period lasting 21 d. The omasal sampling technique in combination with a triple marker method was used to measure nutrient flows to the omasum with Co-EDTA, Yb acetate, and indigestible NDF as liquid, small particle, and large particle phase markers, respectively. Microbial N flow was assessed from purine base concentrations. Steers fed CS, FWCW, and UPWCW consumed 2.7, 2.4, and 2.6 kg/d more (P < 0.05) forage and total DMI, respectively, than those fed GS-based diets. Rumen pH (P = 0.07) and lactic acid (P = 0.11) concentration did not differ between the forages. Rumen concentration of NH(3)-N was greatest for UPWCW and least for CS (P < 0.001). Total VFA concentrations were greater (P < 0.05) for CS than GS and UPWCW, with FWCW being intermediate. Acetate-to-propionate ratio (P < 0.05) was greater (P < 0.05) for UPWCW than the other forages, which did not differ. Apparent ruminal digestion of OM (P < 0.05) was less for CS, FWCW, and UPWCW than GS. Ruminal NDF digestibility was greater (P < 0.01) for GS than the other forages, which did not differ (P > or = 0.06). Total tract NDF digestibility was less (P < 0.05) for UPWCW than the other forages, with GS being greatest and CS and FWCW being intermediate. Starch intake was less (P < 0.001) for GS than the other forages, but there was no effect of forage on omasal starch flow (P = 0.23) or ruminal digestibility (P = 0.88). Flow of non-NH(3)-N and microbial N was greater (P < 0.05) for CS, FWCW, and UPWCW than GS. Efficiency of microbial N synthesis was greater (P < 0.05) for FWCW than GS and CS, with UPWCW being intermediate. Plasma beta-hydroxybutyrate concentrations were greatest with CS and least for GS (P < 0.001), whereas concentrations of plasma urea were least for CS and greatest for UPWCW (P < 0.001). In conclusion, feeding alternative forages to GS can significantly increase feed DMI and alter rumen fermentation and site of nutrient digestion when offered to cattle supplemented with 3 kg of concentrate daily.     

Regional fisheries management organizations and the new biodiversity agreement: Challenge or opportunity?

In 2018, the international community began formal intergovernmental negotiations over a new legally binding instrument for the protection of marine biodiversity of areas beyond national jurisdiction. Protecting marine biodiversity is imperative for a sustainable future, and all the different organizations and agreements will have to work together to achieve this common goal. One of the first key principles to be agreed was to “not undermine” the existing legal instruments or mandates of regional and sectoral marine governance organizations. While fisheries are not being discussed during the negotiations, a marine biodiversity agreement is likely to still impact regional fisheries management organizations (RFMOs), due to overlapping areas of interest. This article aims to firstly, assess the potential constraints posed by the commitment to “not undermine”; secondly, consider how aspects of the biodiversity agreement, such as area‐based management and environmental impact assessments, might enhance RFMOs; and thirdly, suggest meaningful ways to ensure cooperation between RFMOs and the marine biodiversity agreement.     

Consistent Quantitative Trait Loci in Pea for Partial Resistance to Aphanomyces euteiches Isolates from the United States and France

ABSTRACT Development of pea cultivars resistant to Aphanomyces root rot, the most destructive root disease of pea worldwide, is a major disease management objective. In a previous study of a mapping population of 127 recombinant inbred lines (RILs) derived from the cross 'Puget' (susceptible) x '90-2079' (partially resistant), we identified seven genomic regions, including a major quantitative trait locus (QTL), Aph1, associated with partial resistance to Aphanomyces root rot in U.S. fields (21). The objective of the present study was to evaluate, in the same mapping population, the specificity versus consistency of Aphanomyces resistance QTL under two screening conditions (greenhouse and field, by comparison with the previous study) and with two isolates of Aphanomyces euteiches originating from the United States and France. The 127 RILs were evaluated in the greenhouse for resistance to pure culture isolates SP7 (United States) and Ae106 (France). Using the genetic map previously described, a total of 10 QTL were identified for resistance in greenhouse conditions to the two isolates. Among these were Aph1, Aph2, and Aph3, previously detected for partial field resistance in the United States. Aph1 and Aph3 were detected with both isolates and Aph2 with only the French isolate. Seven additional QTL were specifically detected with one of the two isolates and were not identified for partial field resistance in the United States. The consistency of the detected resistance QTL over two screening environments and isolates is discussed with regard to pathogen variability, and disease assessment and QTL detection methods. This study suggests the usefulness of three consistent QTL, Aph1, Aph2, and Aph3, for marker-assisted selection.