20 research outputs found

    Nematódeos e bactérias em fôlhas de alcachôfra

    Get PDF
    Diseased plants of artichoke (Cynara scolimus L.) from the Instituto AgronĂ´mico, Campinas, Brazil, harboured nematodes in the leaves. The nematodes proved to belong to the species Protorhabditis oxyuris (Claus, 1862) Dougherty, 1955. As it could not be charged as the primary agent of the disease, a study of the bacteria found in the material was made. This disclosed that 4 different bacterial forms were present, namely Bacillus subtilis, Bacterium udum, Xanthomonas beticola var. cynarae n. var., and Cory neb acterium fascians var. cynarae n. var. The typical forms of X. beticola and of C. fascians are known as pathogenic to a number of plants: but, in the present case, unfortunately no inoculation trial could be made as an attempt to clear up the possible pathogenicity of any of them also to Cynara scolimus. The nematode P. oxyuris is the secondary agent, which however possibly play an important part in the distribution of the bacteria, as it has been repeatedly pointed out by previous writers with reference to closely related species. The symptoms of the disease are described. The main injuries found on leaves were necrotic areas progressing from the distal part of the limb, resulting in a great reduction of the leaf superficies

    Comparing trawl and creel fishing for Norway lobster (Nephrops norvegicus): biological and economic considerations

    Get PDF
    This study compares the fishing activity and landings of the trawl and creel fisheries for Norway lobster (Nephrops norvegicus (L.)) off the Portuguese coast, and evaluates the financial viability of two vessels typical of each fleet. Crustacean trawlers are part of an industrial fleet that, besides Nephrops, targets deep water shrimps. Creels are used by a multi-gear, multi-target artisanal fleet, fishing only in areas unavailable to trawlers and, when catching Nephrops, set specifically to target this species. Trawlers have in recent years contributed with 85% of the landings in weight, but only 74% in value (2005-2009 average). Despite smaller landings, the Nephrops creel fishery provides individuals of larger size and in better condition, thereby obtaining higher unit prices. Economic viability was also higher for the creel vessel, with trawling being only viable if major costs (such as labor and fuel) are covered by the revenue from other target species (e. g., the rose shrimp). At present, Nephrops populations on the South and SW coast are subject to intense fishing and to a recovery plan. The possibility of reallocation of some of the fishing effort directed at Nephrops from trawlers to creels is discussed in terms of the conservation of the resource and economic return.Foundation for Science and Technology, Portugal: Project "Nephrops survival when escaping from trawls nets and by-catch escaping devices" [PDCT/MAR/59366/2004]; Foundation for Science and Technology, Portugal: Project "Environmental impact of fixing gears in the southwest coast of Portugal. Combine fisheries and marine ecosystem conservation" [POCTI/CTA/49248/2002]info:eu-repo/semantics/publishedVersio
    corecore