226 research outputs found
Resistance of Soybean Genotypes to Anticarsia gemmatalis (Lepidoptera: Erebidae): Antixenosis and Antibiosis Characterization
Injury by herbivores is a major biotic stress that limits soybean [Glycine max (L.) Merrill] crop production. Among the main soybean insect pests, Anticarsia gemmatalis HĂŒbner is responsible for causing significant economic damage in soybean. The primary management strategy for this insect is chemical control and use of Bt transgenic soybean. Alternative strategies, such as host plant resistance, are considered an efficient and less-aggressive method, especially in association with other strategies as part of an integrated pest management (IPM) approach. In this study, we evaluated 30 soybean genotypes to verify antixenosis expression through oviposition, attractiveness, and food consumption tests. From this, we selected 13 promising genotypes to verify the possible presence of antibiosis. Our results suggest that antixenosis was found in genotypes âTMG 133â RR, âTMG 1179â RR, âIAC 19â, âIAC 17â, âIAC 100â, D75-10169, and IAC 78-2318. By influence on behavior and negative impact on larval viability, antixenosis and antibiosis were indicated for the genotypes IAC 74-2832, âIAC 19â, âIAC 17â, âIAC 100â, and PI 274454. âTMG 7062â IPRO was found to provide antibiosis resistance by negatively affecting larval development and viability. Because of reduced food consumption by larvae, antixenosis was indicated for âIAC 24â. These genotypes should be considered in soybean breeding programs focusing on soybean resistance to A. gemmatalis
Generation of Bianchi type V cosmological models with varying -term
Bianchi type V perfect fluid cosmological models are investigated with
cosmological term varying with time. Using a generation technique
(Camci {\it et al.}, 2001), it is shown that the Einstein's field equations are
solvable for any arbitrary cosmic scale function. Solutions for particular
forms of cosmic scale functions are also obtained. The cosmological constant is
found to be decreasing function of time, which is supported by results from
recent type Ia supernovae observations. Some physical aspects of the models are
also discussed.Comment: 16 pages, 3 figures, submitted to CJ
Equation of state for Universe from similarity symmetries
In this paper we proposed to use the group of analysis of symmetries of the
dynamical system to describe the evolution of the Universe. This methods is
used in searching for the unknown equation of state. It is shown that group of
symmetries enforce the form of the equation of state for noninteracting scaling
multifluids. We showed that symmetries give rise the equation of state in the
form and energy density
, which
is commonly used in cosmology. The FRW model filled with scaling fluid (called
homological) is confronted with the observations of distant type Ia supernovae.
We found the class of model parameters admissible by the statistical analysis
of SNIa data. We showed that the model with scaling fluid fits well to
supernovae data. We found that and (), which can correspond to (hyper) phantom fluid, and to a
high density universe. However if we assume prior that
then the favoured model is close to concordance
CDM model. Our results predict that in the considered model with
scaling fluids distant type Ia supernovae should be brighter than in
CDM model, while intermediate distant SNIa should be fainter than in
CDM model. We also investigate whether the model with scaling fluid is
actually preferred by data over CDM model. As a result we find from
the Akaike model selection criterion prefers the model with noninteracting
scaling fluid.Comment: accepted for publication versio
The nitrogen sufficiency index underlying estimates of nitrogen fertilization requirements of common bean
Integrated analysis of water quality from two rivers used for public supply in southern Brazil
Desinfestação superficial, germinação e regeneração in vitro a partir de sementes de calĂȘndula
Colonization by benthic macroinvertebrates in two artificial substrate types of a Riparian Forest
Produtividade do feijoeiro em resposta a adubação fosfatada e a regimes de irrigação em solo de cerrado
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