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Areia Branca, Brazil

De Souza Ferraz R.L.,Sao Paulo State University | De Macedo Beltrao N.E.,EMBRAPA - Empresa Brasileira de Pesquisa Agropecuaria | De Melo A.S.,State University of Paraiba | Magalhaes I.D.,CSIC - Institute of Agricultural Sciences | And 2 more authors.
Semina:Ciencias Agrarias | Year: 2014

The objective of this study was to evaluate gas exchange and photochemical efficiency of cotton cultivars under leaf application of silicon. Therefore, the experiment was conducted in a completely randomized in a factorial 3 x 5, three cotton cultivars ('BRS Topázio', 'BRS Safira' and 'BRS Rubi'), five silicon concentrations (0, 50, 100, 150, 200 mg L-1) and four replications. Gas exchange and photochemical efficiency were determined by measuring the rate of CO2 assimilation, transpiration, stomatal conductance, internal CO2 concentration, instantaneous efficiency in water use, instantaneous carboxylation efficiency, initial fluorescence, maximum quantum efficiency of the variable and photosystem II (PSII). The data variables were subjected to analysis of variance and regression test comparison of means. There were significant differences in gas exchange and photochemical efficiency in response to concentrations of silicon. There were also significant differences among cotton cultivars evaluated. In cultivar 'BRS Topázio', the application of silicon increased CO2 assimilation rate and quantum efficiency of PSII. In 'BRS Safira' silicon reduced the rate of assimilation and internal CO2 concentration. In 'BRS Rubi' element increased the fluorescence of chlorophyll 'a' and quantum efficiency of photosystem II, and reduced the rate of assimilation and internal CO2 concentration and stomatal conductance. Silicate fertilization provided 'BRS Topázio' to express better photosynthetic rate in relation to 'BRS Safira' and 'BRS Rubi'. No damage occurred in PSII when 'BRS Topázio', 'BRS Safira' and 'BRS Rubi' cultivars received silicon as supplementary nutrition. Source


Aguiar A.F.,Sao Paulo State University | Aguiar D.H.,UEPB | Felisberto A.D.S.,Sao Paulo State University | Carani F.R.,Sao Paulo State University | And 3 more authors.
Journal of Strength and Conditioning Research | Year: 2010

The purpose of this study was to utilize a rodent model to test the hypothesis that creatine (Cr) supplementation during resistance training would influence the pattern of slow-twitch muscle myosin heavy chain (MHC) isoforms expression. Male Wistar rats (2-3 months old, 250-300 g) were divided into 4 groups: Nontrained without creatine supplementation (CO), nontrained with creatine supplementation (CR), trained without creatine supplementation (TR), and trained with creatine supplementation (TRCR). TR and TRCR groups were submitted to a resistance training program for 5 weeks (5 days/week) for morphological and biochemical analysis of the soleus muscle. Weightlifting exercise involved jump sessions into water, carrying progressive overload equivalent to percentage of body weight. CR and TRCR groups were given creatine at 0.5 g/kg-1/d-1. Both Cr supplementation and resistance training alone or associated did not result in significant alterations (p > 0.05) in body weight gain, food intake, and muscle weight in the CR, TR and TRCR groups compared to the CO group. Also compared to the CO group, the CR group showed a significant (p < 0.02) increase in MHCI content and a reduction in MHCII; inversely, the TR group increased the MHCII content and reduced MHCI (p < 0.02). When combined, both creatine and resistance training did not promote significant (p > 0.05) changes in MHC content of the TRCR group compared to the CO group. The data show that Cr supplementation provides a potential action to abolish the exercise-induced MHC isoform transitions from slow to fast in slow-twitch muscle. Thus, Cr supplementation might be a suitable strategy to maintaining a slow phenotype in slow muscle during resistance training, which may be favorable to maintenance of muscle oxidative capacity of endurance athletes. © 2010 National Strength and Conditioning Association. Source


Ozaki V.A.,University of Sao Paulo | Olinda R.,UEPB | Faria P.N.,Federal University of Uberlandia | Campos R.C.,Federal University of Pelotas
Revista de Economia e Sociologia Rural | Year: 2014

In any agricultural insurance program, the accurate quantification of the probability of the loss has great importance. In order to estimate this quantity, it is necessary to assume some parametric probability distribution. The objective of this work is to estimate the probability of loss using the theory of the extreme values modeling the left tail of the distribution. After that, the estimated values will be compared to the values estimated under the normality assumption. Finally, we discuss the implications of assuming a symmetrical distribution instead of a more flexible family of distributions when estimating the probability of loss and pricing the insurance contracts. Results show that, for the selected regions, the probability distributions present a relative degree of skewness. As a consequence, the probability of loss is quite different from those estimated supposing the Normal distribution, commonly used by Brazilian insurers. Source


Dos Santos J.G.R.,CCHA UEPB | Andrade R.,CCHA UEPB | Galdino P.O.,UEPB | Linhares A.S.F.,CCHA UEPB | And 2 more authors.
Revista Brasileira de Engenharia Agricola e Ambiental | Year: 2014

The objective of this research was to study the effects of 5 doses of 4 different types of biofertilizer in production of banana Nanicão in 3 successive cycles. The experiment was conducted under field conditions at Escola Agrotécnica of the Cajueiro in the municipality of Catolé do Rocha, in the state of Paraíba, Brazil. The soil in the area is classified as Entisol with sandy loam texture. The experiment was conducted during June 2008 to June 2011. The experimental design was a randomized block design with 20 treatments in a 5×4 factorial scheme (doses × types) of biofertilizers with four replications. The results show that the types of biofertilizers did not affect the production quality, the length and diameter of fruit increased with increasing dose of biofertilizer to optimum limits, the length of the fruit of the second cycle was more than that of plants of first and third cycles, the diameter of the fruit of the second cycle of the crop was higher than the first and third cycles and values of oBrix and pH of the pulp of the fruit were not affected by biofertilizer doses. Source


de Mesquita E.F.,UEPB | Chaves L.H.G.,Federal University of Campina Grande | Guerra H.O.C.,Federal University of Campina Grande | de Lacerda R.D.,Federal University of Campina Grande
Revista Caatinga | Year: 2012

The actual paper was carried out aiming to evaluate the effects of nitrogen, phosphorus and potassium on the growth and seeds production of castor bean (Ricinus communis L.), cultivar BRS Nordestina and BRS Paraguaçu. For each cultivar an experiment was conducted in a greenhouse, in Campina Grande, PB. Each experiment was conducted on a 2 × 2 × 2 factorial design completely randomized resulting 24 experimental units, subjected to the following levels of fertilization: nitrogen (200 and 300 kg ha -1), phosphorus (150 and 250 kg ha -1) and potassium (150 and 250 kg ha -1). Plant height, stem diameter, number of leaves and leaf area were measured at 20, 40, 60, 80, 100, 120, 140 and 160 days after planting. At the end of the experiment the weight of seeds was measured. Nitrogen was the nutrient that promoted the highest growth and yield for both cultivars; the phosphorus and potassium application did not influence the stem diameter, leaf area and the yield of castor bean; the highest plant height was obtained with the treatment N 1P 1K 1 (200-150-150 kg ha -1). Source

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