Atributos do solo impactados por cultivos sucessivos de arroz de terras altas.

O objetivo deste trabalho foi determinar, utilizando esse tipo de análise, quais atributos de um Latossolo Vermelho de Cerrado são mais impactados por cultivos sucessivos de arroz de terras altas sob semeadura direta

Interprocedural Reachability for Flat Integer Programs

We study programs with integer data, procedure calls and arbitrary call graphs. We show that, whenever the guards and updates are given by octagonal relations, the reachability problem along control flow paths within some language w1* ... wd* over program statements is decidable in Nexptime. To achieve this upper bound, we combine a program transformation into the same class of programs but without procedures, with an Np-completeness result for the reachability problem of procedure-less programs. Besides the program, the expression w1* ... wd* is also mapped onto an expression of a similar form but this time over the transformed program statements. Several arguments involving context-free grammars and their generative process enable us to give tight bounds on the size of the resulting expression. The currently existing gap between Np-hard and Nexptime can be closed to Np-complete when a certain parameter of the analysis is assumed to be constant.Comment: 38 pages, 1 figur

Sensitivity of Corynespora cassiicola from soybean to carbendazim and prothioconazole.

The incidence of target spot disease on soybean has increased in recent years in Brazil even with intensive use of fungicides, and fungal resistance has been reported in recent studies. The objective of this study was to determine the fungicide sensitivity to carbendazim and prothioconazole in a sample of 24 isolates of Corynespora cassiicola from soybean collected from 1996 to 2011 in the states of Paraná, Mato Grosso and São Paulo (Brazil) and Corpus Christi (Paraguay). The 50% effective concentration (EC50) values were estimated by the relative mycelium growth reduction on fungicide-amended medium with the doses of 0, 0.5, 1, 10, 100 and 1000 µg of active ingredient/ mL. For carbendazim, four highly resistant isolates (EC50 > ou = 50 µg/mL) were observed from samples collected from Mato Grosso in 2008 and from Paraná and Mato Grosso in 2011. The EC50 values for prothioconazole ranged from 0.47 µg/mL to 26.44 µg/mL (mean: 5.02 µg/mL). The results reinforce the occurrence of C. cassiicola resistance to benzimidazole in Paraná and Mato Grosso states

Fotossíntese de folhas de soja infectadas por Corynespora cassiicola e Erysiphe diffusa.

RESUMO: A estimativa visual da severidade de doenças em plantas nem sempre se correlaciona com o efeito desta sobre a atividade fotossintética do hospedeiro. O objetivo do trabalho foi avaliar a interferência dos fungos Corynespora cassiicola e Erysiphe diffusa, causadores da mancha-alvo e do oídio na cultura da soja, respectivamente, na eficiência fotossintética de folhas infectadas. A fotossíntese foi relacionada com a área foliar doente por meio da equação Px/Po=(1-x)β. Os parâmetros β (± erro padrão) estimados foram 2,78 (± 0,28) (p1) indica que houve redução da eficiência fotossintética no tecido lesionado e em parte do tecido verde remanescente, enquanto que os valores obtidos para E. diffusa (β≤1) indicam que a estimativa visual da severidade da doença é um bom indicador do efeito do fungo na taxa fotossintética do hospedeiro. ABSTRACT: The visual estimate of the disease severity in plants does not always correlate with its effect on the host?s photosynthetic activity. The aim of this study was evaluate the interference of the fungi Corynespora cassiicola and Erysiphe diffusa, causal agents of target spot and powdery mildew on soybeans, in the photosynthetic efficiency of infected leaves. Photosynthesis was related to the diseased leaf area by the equation Px/Po = (1-x)β. The estimated parameters β (± standard error) were 2.78 (± 0.28) (p1) indicates that there was a reduction in the photosynthetic efficiency in the injured tissue and in part of the remaining green tissue, while the values obtained for E. diffusa (β≤1) indicate that the visual estimate of the disease severity is a good indicator of the effect of the fungus on the photosynthetic rate

Sensitivity monitoring of Phakopsora pachyrhizi populations to triazoles in Brazil.

Asian soybean rust (ASR), reported for the first time in 2001 in South America, spread quickly to the major Brazilian soybean-producing regions and is considered one of the most important diseases of the crop in Brazil. Fungicides for ASR control belong to QoI (strobilurins) and SBI (azole) compounds. A lower efficiency of straight azole fungicides has been observed since 2006–2007. Embrapa Soybean Researcher Center started a sensitivity monitoring program for P. pachyrhizi in 2008–2009 to detect changes in the EC50 values (half maximal effective concentration) of the fungi population to triazoles. The bioassay has been carried out according to FRAC (Fungicide Resistance Action Committee) methodology. In the 2010–2011 growing season, leaf samples infected with P. pachyrhizi were sent from nine Brazilian states, in a total of 54 populations, and the spores collected were inoculated in detached leaves treated with the fungicides cyproconazole, metconazole, tebuconazole (0, 0.16, 0.45, 1.3, 3.8, 11, and 32 ppm), and prothioconazole (0, 0.02, 0.06, 0.164, 0.5, 1.4, and 8 ppm). Disease severity was evaluated 15 days after inoculation and only 16 bioassays showed ASR severity above 5%. The EC50 values were estimated by Proc Probit, SAS. The averages of EC50 were 0.59 for cyproconazole, 0.37 for metconazole, 0.33 for tebuconazole, and 0.1 for prothioconazole. These values were similar to the average values estimated in 2008–2009 and 2009–2010

Energy use and height in office buildings

The relationship between energy use and height is examined for a sample of 611 office buildings in England and Wales using actual annual metered consumption of electricity and fossil fuels. The buildings are of different ages; they have different construction characteristics and methods of heating and ventilation; and they include both public and commercial offices. When rising from five storeys and below to 21 storeys and above, the mean intensity of electricity and fossil fuel use increases by 137% and 42% respectively, and mean carbon emissions are more than doubled. A multivariate regression model is used to interpret the contributions of building characteristics and other factors to this result. Air-conditioning is important, but a trend of increased energy use with height is also found in naturally ventilated buildings. Newer buildings are not in general more efficient: the intensity of electricity use is greater in offices built in recent decades, without a compensating decrease in fossil fuel use. The evidence suggests it is likely – although not proven – that much of the increase in energy use with height is due to the greater exposure of taller buildings to lower temperatures, stronger winds and more solar gains