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| Registros recuperados: 2.080 | |
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| CHOUDHURY, M. M.. |
| As sementes, estacas, bulbos, tubérculos, etc., são órgãos de propagação vegetal e eficientes veículos de disseminação de fitopatógenos em campos agrícolas. Como as sementes contribuem com aproximadamente 90% para a propagação das culturas, muitos fungos, bactérias, virus e alguns fitonematóides podem apresentar-se associados as mesmas, causando severos danos as culturas. Estes fitopatógenos, em condições favoraveis, sobrevivem nas sementes de um ano para outro; ou por período mais longo durante o armazenamento. São apresentados no trabalho os danos causados por sementes infectadas ou contaminadas, os meios de disseminação de fitopatógenos pelas sementes e como evitar a introdução de doenças na região. Com relação a colheita, dois aspectos básicos devem... |
| Tipo: Comunicado Técnico (INFOTECA-E) |
Palavras-chave: Propagação; Seed; Diseases; Propagation; Disease.; Planta; Doença; Semente.. |
| Ano: 1982 |
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/131789 |
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| Schalkwijk, Joost; Jansen, Gerrit M.. |
| During our stay in the Nothofagus region near Osorno from April to July 1979, we collected an interesting species of Amanita, Unlike A. diemii Sing., which appeared to be rather common in this area, the new species was collected only once. Our Amanita is undoubtedly identical with A. gayana (Mont.) Mont., as described by Singer (1969: 151). However, checking the protologue of Agaricus gayanus Mont. (1853: 332), we soon discovered that we were dealing with two different species. Therefore we have to describe our (and Singer’s) species as a new one, naming it A. aurantiovelata. |
| Tipo: Article / Letter to the editor |
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| Ano: 1982 |
URL: http://www.repository.naturalis.nl/record/531924 |
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| Barendregt, A.; Dries, P.J.L. van den; Sipman, H.J.M.. |
| The well-known and widespread lichen species Cladonia furcata (Huds.) Schrad. is usually very constant in its chemistry: fumarprotocetraric acid is its main secondary metabolite, sometimes accompanied by atranorin. Recently a new chemical strain, characterised by the presence of psoromic acid instead of fumarprotocetraric acid or atranorin, was found in Portugal by the first two authors during phytosociological investigations of heath vegetations. The plants are preserved in the herbarium of the Institute of Systematic Botany, University of Utrecht (U), leg. Barendregt & v.d. Dries nr. 1-2 (U). Morphologically the plants with psoromic acid represent the slender form of C. furcata. which is the predominant form in lowland western Europe (fig. 1). The... |
| Tipo: Article / Letter to the editor |
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| Ano: 1982 |
URL: http://www.repository.naturalis.nl/record/534898 |
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| Wägele, Johann Wolfgang. |
| Cyathuva numeae n.sp. from New Caledonia is the sixth blind species of the genus Cyathura Norman & Stebbing, 1886, found in hypogean habitats. The new species lives in the interstitia of coastal sand or gravel, like C. milloti Chappuis et al., 1956, from Réunion. A close relationship to the other species is not obvious; the specific shape of the appendix masculina can be derived from the carinata-type. In contrast to the slender species, C. curassavica Stork, 1940, and C. specus Bowman, 1965, in the new species the adaptations to hypogean life are limited to the small body size and reduction of the eyes. |
| Tipo: Article / Letter to the editor |
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| Ano: 1982 |
URL: http://www.repository.naturalis.nl/record/505318 |
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| Musser, G.G.; Piik, E.. |
| A new species of the murid Hydromys is named and described, based on skins, skulls and denti tions. The sample comes from the Wissel Lakes region in the Indonesian half of New Guinea (Irian Jaya). In many features, the new species is a miniature version of Hydromys chrysogaster and may be more closely related to that large water rat than to H. habbema. Nothing is known about habits or habitat of the new rat, and it has not yet been collected elsewhere in Irian Jaya or in the eastern half of New Guinea (Papua). |
| Tipo: Article / Letter to the editor |
Palavras-chave: 42.84. |
| Ano: 1982 |
URL: http://www.repository.naturalis.nl/record/318530 |
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| Leyen, A. van; Spoel, S. van der. |
| Re-examination of the Diacria quadridentata species group based upon morphology of the shell and zoogeographic data, led to a new classification comprising the recent taxa: D. quadridentata, D. costata with an equatorial and a central water form, D. danae with an equatorial and a central water form, D. schmidti schmidti, D. erythra crassa and the fossil taxa D. schmidti cocidentalis and D. erythra erythra from surface sediments. A method has been developed to estimate the relative age of the population, based on the development of shell and soft parts. Shell growth in the period of minute and adult stages together does not exceed 0.2 mm, and differs from species to species. |
| Tipo: Article / Letter to the editor |
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| Ano: 1982 |
URL: http://www.repository.naturalis.nl/record/505420 |
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| Hamal, K.B.; Anderson, Jock R.. |
| Attitudes toward risk are explored for a sample of rice growers on small farms in Nepal, in the context of the subjective expected utility maximisation model. Farmers are found to be generally averse to risk, with diverse levels of absolute risk aversion that tend to diminish as wealth increases, both for individuals and in a cross-sectional sense. Relative risk aversion is argued to be the most comparable measure for contrasts of attitudes toward risk. |
| Tipo: Journal Article |
Palavras-chave: Risk and Uncertainty. |
| Ano: 1982 |
URL: http://purl.umn.edu/22708 |
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| Reeves, G.W.; Longmire, James L.. |
| The view is taken that institutional factors operating in the international beef market limit the usefulness of a competitive spatial equilibrium model for understanding the process of price formation in the Australian beef market. A simple theoretical model is developed to demonstrate the impact of the U.S. beef quota and Australia's meat export control scheme on Australian beef prices. It is argued that Australian beef prices are related to the weighted average of export prices rather than any "world" price. Implications for the direction and volume of Australia's beef exports are discussed. |
| Tipo: Journal Article |
Palavras-chave: Demand and Price Analysis; Livestock Production/Industries. |
| Ano: 1982 |
URL: http://purl.umn.edu/12294 |
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| Tanner, A.c.; Herbert, R.a.. |
| One hundred and forty four Gram-negative bacteria, indigenous to the maritime Antarctic environment, together with six reference strains, were examined for ninety four unit characters, including morphology, production of exoenzymes, growth temperature characteristics and ability to utilize various organic carbon sources. The resulting data were analysed using the Ssm and Sj similarity coefficients with the UPGMA algorithm. At a 70% level of similary, 97% of the isolates were included in ten clusters. 50% of the isolates were identified as belonging to the genera Aeromonas/Vibrio ; 22 %, Alcaligenes ; 2%, Pseudomonas ; and 2% Flavobacterium. The remainder could not easily be identifed with bacteria previously described in the Eighth edition of Bergey's... |
| Tipo: Text |
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| Ano: 1982 |
URL: http://archimer.ifremer.fr/doc/00306/41741/40952.pdf |
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| Registros recuperados: 2.080 | |
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