Agronomic characterization of autotetraploid banana plants derived from ‘Pisang Lilin’ (AA) obtained through chromosome doubling     

Cícera Maria do Amaral  Janay de Almeida dos Santos-Serejo  Sebastião de Oliveira e Silva  Carlos Alberto da Silva Ledo  Edson Perito Amorim 《Euphytica》2015,202(3):435-443

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Herbage utilisation efficiency of continuously stocked pastures during periods of restricted pasture growth     

Tiago Miqueloto  Cauby de Medeiros Neto  Clovis David Medeiros Martins  Rodrigo Amorim Barbosa  Sila Carneiro Da Silva  André Fischer Sbrissia 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2020,70(3):208-214

ABSTRACT

The aim of this study was to evaluate the defoliation patterns of individual tillers, efficiency of herbage utilisation, and forage production in continuously stocked Brachiaria humidicola cv. Comum swards during periods of the year of restricted pasture growth. The experiment was conducted at the Embrapa, Campo Grande-MS, Brazil, from April to October 2012. Treatments consisted of two grazing management strategies, defined by two ranges of sward height (10–15 and 20–25 cm) managed under continuous and variable stocking rates. The experiment was conducted as a completely randomised block design with three replications. During periods of resource constraints, grazing management strategies based on ‘steady state’ sward heights did not alter defoliation patterns, herbage utilisation efficiency (HUE), and forage production in Brachiaria humidicola swards under a continuous stocking method. A direct implication of our results is that grazing management strategies during the driest and coldest periods of the year in the tropics should be developed based on the conditions most suitable for better promoting faster pasture recovery and a return to production in the following spring; it is unlikely that any grazing management strategy would be successful in increasing herbage production and/or HUE in periods of restricted pasture growth.  相似文献   

Essential oils from plants and in vitro shoots of Hypericum androsaemum L     

Guedes AP  Amorim LR  Vicente AM  Ramos G  Fernandes-Ferreira M 《Journal of agricultural and food chemistry》2003,51(5):1399-1404

The essential oil yields obtained by hydrodistillation of the aerial parts of Hypericum androsaemum cultivated plants varied from 0.94 to 4.09 mg/g of biomass dry weight, depending of the harvest time. The respective analyses performed by gas chromatography and gas chromatography-mass spectrometry revealed more than 80 compounds, 72 of which were identified. Most of the compounds were sesquiterpene hydrocarbons, which, depending of the harvest time, corresponded to 43-78% of the total essential oil. The other compounds were distributed as monoterpene hydrocarbons, oxygen-containing sesquiterpenes, n-alkanes, 1-alkenes, and oxygen-containing monoterpenes, these being a minor group. In H. androsaemum in vitro shoots, sesquiterpene hydrocarbons represented >80% of the respective essential oil. Differences in the essential oil composition were found depending on the harvest time and origin, in vivo versus in vitro, of the plant material. The essential oil sampled in November was characterized by the highest levels of sesquiterpene hydrocarbons and a high number of n-alkanes and 1-alkenes, from C(18) to C(28), whereas that sampled in June of the following year showed the highest levels of n-nonane and 1-octene as well as monoterpene hydrocarbons, the second most representative group.  相似文献   

Local perceptions of jaguars (Panthera onca) and pumas (Puma concolor) in the Iguaçu National Park area, south Brazil     

Valéria Amorim Conforti  Fernando Cesar Cascelli de Azevedo 《Biological conservation》2003,111(2):215-221

Jaguars (Panthera onca) have been killed by local residents within the boundaries and lands surrounding Iguaçu National Park (INP), Brazil. Both jaguars and pumas (Puma concolor) occur in the region, however, livestock predation by pumas has rarely been reported. Our objective was to assess the local perceptions about jaguars and pumas. We identified two major factors that distinguished the perceptions towards the two species: less people feared the puma than the jaguar; and most people believed that jaguars, but not pumas, were released into INP by local authorities. Interestingly, despite those major differences in these perceptions, feelings towards the two species tended to be the same. Perceptions towards jaguars were not influenced by the predation history of the properties, suggesting that the predation impact was not remarkable enough to influence local perceptions towards carnivores. This is apparently the first study on local perceptions towards large carnivores in Brazil.  相似文献   

BIRDS THAT SING IN THE NIGHT     

Edson JM 《Science (New York, N.Y.)》1893,22(559):221-222

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Revisiting the taxonomic impediment     

de Carvalho MR  Bockmann FA  Amorim DS  de Vivo M  de Toledo-Piza M  Menezes NA  de Figueiredo JL  Castro RM  Gill AC  McEachran JD  Compagno LJ  Schelly RC  Britz R  Lundberg JG  Vari RP  Nelson G 《Science (New York, N.Y.)》2005,307(5708):353

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Comment on "Drought-induced reduction in global terrestrial net primary production from 2000 through 2009"     

Samanta A  Costa MH  Nunes EL  Vieira SA  Xu L  Myneni RB 《Science (New York, N.Y.)》2011,333(6046):1093; author reply 1093

Zhao and Running (Reports, 20 August 2010, p. 940) reported a reduction in global terrestrial net primary production (NPP) from 2000 through 2009. We argue that the small trends, regional patterns, and interannual variations that they describe are artifacts of their NPP model. Satellite observations of vegetation activity show no statistically significant changes in more than 85% of the vegetated lands south of 70°N during the same 2000 to 2009 period.  相似文献   

Mycoplasma meleagridis of turkeys: probability of eliminating egg-borne infection   总被引：1，自引：0，他引：1  

R K Edson  R Yamamoto  T B Farver 《Avian diseases》1987,31(2):264-271

An equation was developed that describes the probability of eliminating egg-borne Mycoplasma meleagridis (MM) of turkeys by egg treatment. Probability (P) of MM elimination was described in terms of four parameters: pretreatment prevalence of MM, alpha; treatment failure rate, beta; number of eggs treated, n; and hatching rate, h. The eradication equation, based on the Poisson probability distribution, was P(0) = e-n alpha beta h. Probabilities derived from 12 hypothetical MM-eradication situations showed that increasing the size of any or all of the parameters decreased the likelihood of eradication. Use of the predictive equation as a planning tool in a successful MM-eradication program is demonstrated.  相似文献   

Modeling tree cover changes in a pasture-dominated landscape by adopting silvopastoral practices in a dry forest region in Central Brazil     

Potira Meirelles Hermuche  Daniel Luis Mascia Vieira  Edson Eyji Sano 《Agroforestry Systems》2013,87(4):881-890

Pastures are a major soil cover in Central Brazil, especially in rich soils previously occupied by dry forests. We simulated a scenario in which the wooden fences in Paranã Valley are replaced by live fences and isolated trees are left in the pasture fields, and we verified changing in tree cover by adding trees and avoiding logging for wooden fences. The simulation involved the analysis of a 20-year historic series of LANDSAT satellite images to determine the average time of pasture renewal. The average amount of wooden fences produced per hectare of local forest was estimated based on the literature and field data. The high spatial-resolution satellite images available in the Google Earth? program were analyzed to estimate the total length of the fences and the average and maximum number of isolated trees per hectare found in the pastures of the region. The results showed that pasture renewal happens every 8.1 years. It is possible to produce an average of 1,472 stakes per hectare of forest. In the study area, we estimated the existence of an average of 842 km of wooden fences and 3.9 isolated trees per hectare of pasture (maximum = 48 isolated trees). The results of the simulation showed that the adoption of live fences can increase the crown coverage up to 7.5 % or even up to 14.3 % if all of the pasturelands are managed to have live fences and farmers begin to adopt cover-development practices, such as keeping an average of 48 isolated trees per hectare of pasture.  相似文献   

Natural infection of turkeys by infectious laryngotracheitis virus   总被引：1，自引：0，他引：1  

Portz C  Beltrão N  Furian TQ  Júnior AB  Macagnan M  Griebeler J  Lima Rosa CA  Colodel EM  Driemeier D  Back A  Barth Schatzmayr OM  Canal CW 《Veterinary microbiology》2008,131(1-2):57-64

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