Impacts of deforestation on water balance components of a watershed on the Brazilian East Coast

The Brazilian East coast was intensely affected by deforestation, which drastically cut back the original biome. The possible impacts of this process on water resources are still unknown. The purpose of this study was an evaluation of the impacts of deforestation on the main water balance components of the Galo creek watershed, in the State of Espírito Santo, on the East coast of Brazil. Considering the real conditions of the watershed, the SWAT model was calibrated with data from 1997 to 2000 and validated for the period between 2001 and 2003. The calibration and validation processes were evaluated by the Nash-Sutcliffe efficiency coefficient and by the statistical parameters (determination coefficient, slope coefficient and F test) of the regression model adjusted for estimated and measured flow data. After calibration and validation of the model, new simulations were carried out for three different land use scenarios: a scenario in compliance with the law (C1), assuming the preservation of PPAs (permanent preservation areas); an optimistic scenario (C2), which considers the watershed to be almost entirely covered by native vegetation; and a pessimistic scenario (C3), in which the watershed would be almost entirely covered by pasture. The scenarios C1, C2 and C3 represent a soil cover of native forest of 76, 97 and 0 %, respectively. The results were compared with the simulation, considering the real scenario (C0) with 54 % forest cover. The Nash-Sutcliffe coefficients were 0.65 and 0.70 for calibration and validation, respectively, indicating satisfactory results in the flow simulation. A mean reduction of 10 % of the native forest cover would cause a mean annual increase of approximately 11.5 mm in total runoff at the watershed outlet. Reforestation would ensure minimum flows in the dry period and regulate the maximum flow of the main watercourse of the watershed.

Water Balance Components in Covered and Uncovered Soil Growing Irrigated Muskmelon

ABSTRACT Knowledge of the terms (or processes) of the soil water balance equation or simply the components of the soil water balance over the cycle of an agricultural crop is essential for soil and water management. Thus, the aim of this study was to analyze these components in a Cambissolo Háplico (Haplocambids) growing muskmelon (Cucumis melo L.) under drip irrigation, with covered and uncovered soil, in the municipality of Baraúna, State of Rio Grande do Norte, Brazil (05º 04’ 48” S, 37º 37’ 00” W). Muskmelon, variety AF-646, was cultivated in a flat experimental area (20 × 50 m). The crop was spaced at 2.00 m between rows and 0.35 m between plants, in a total of ten 50-m-long plant rows. At points corresponding to ⅓ and ⅔ of each plant row, four tensiometers (at a distance of 0.1 m from each other) were set up at the depths of 0.1, 0.2, 0.3, and 0.4 m, adjacent to the irrigation line (0.1 m from the plant row), between two selected plants. Five random plant rows were mulched using dry leaves of banana (Musa sp.) along the drip line, forming a 0.5-m-wide strip, which covered an area of 25 m2 per of plant row with covered soil. In the other five rows, there was no covering. Thus, the experiment consisted of two treatments, with 10 replicates, in four phenological stages: initial (7-22 DAS - days after sowing), growing (22-40 DAS), fruiting (40-58 DAS) and maturation (58-70 DAS). Rainfall was measured with a rain gauge and water storage was estimated by the trapezoidal method, based on tensiometer readings and soil water retention curves. For soil water flux densities at 0.3 m, the tensiometers at the depths of 0.2, 0.3, and 0.4 m were considered; the tensiometer at 0.3 m was used to estimate soil water content from the soil water retention curve at this depth, and the other two to calculate the total potential gradient. Flux densities were calculated through use of the Darcy-Buckingham equation, with hydraulic conductivity determined by the instantaneous profile method. Crop actual evapotranspiration was calculated as the unknown of the soil water balance equation. The soil water balance method is effective in estimating the actual evapotranspiration of irrigated muskmelon; there was no significant effect of soil coverage on capillary rise, internal drainage, crop actual evapotranspiration, and muskmelon yield compared with the uncovered soil; the transport of water caused by evaporation in the uncovered soil was controlled by the break in capillarity at the soil-atmosphere interface, which caused similar water dynamics for both management practices applied.

Phenotypic stability and genetic gains in six-year girth growth of Hevea clones

Rubber tree [Hevea brasiliensis (Willd. ex Adr. de Juss.) Müell. Arg.] budgrafts of seven clones were evaluated on five contrasting sites in the plateau region of the São Paulo State, Brazil. The objective of this work was to study the phenotypic stability for girth growth. The experimental design was a randomized block design with three replications and seven treatments. Analysis of variance of girth at six-year plant growth indicated a highly significant clone x site interaction. Only linear sites and clone x site components of clone x year interaction were significant, indicating that the performance of clones over sites for this trait could be predicted. The clones GT 1 and PB 235 showed the greatest stability in relation to girth growth, with foreseen responses to change, introduced in the sites. The clones PB 235 and IAN 873 showed significative difference in relation to regression coefficient, representing clones with specific adaptability on favorable and unfavorable sites respectively. The clone GT 1 became the most promissory one in the study of stability and adaptability even showing low girth growth. Expected genetic gains from planting sites, along with estimates of clonal variance and repeatability of clonal means are generally greatest or close to the greatest when selection is done at the same site.

Analysis of variance of primary data on plant growth analysis

Plant growth analysis presents difficulties related to statistical comparison of growth rates, and the analysis of variance of primary data could guide the interpretation of results. The objective of this work was to evaluate the analysis of variance of data from distinct harvests of an experiment, focusing especially on the homogeneity of variances and the choice of an adequate ANOVA model. Data from five experiments covering different crops and growth conditions were used. From the total number of variables, 19% were originally homoscedastic, 60% became homoscedastic after logarithmic transformation, and 21% remained heteroscedastic after transformation. Data transformation did not affect the F test in one experiment, whereas in the other experiments transformation modified the F test usually reducing the number of significant effects. Even when transformation has not altered the F test, mean comparisons led to divergent interpretations. The mixed ANOVA model, considering harvest as a random effect, reduced the number of significant effects of every factor which had the F test modified by this model. Examples illustrated that analysis of variance of primary variables provides a tool for identifying significant differences in growth rates. The analysis of variance imposes restrictions to experimental design thereby eliminating some advantages of the functional growth analysis.

Growth components and zinc recovery efficiency of upland rice genotypes

The objective of this work was to evaluate Zn use efficiency by upland rice genotypes. The experiment was carried out in a greenhouse, with ten upland rice genotypes grown on an Oxisol (Typic Hapludox) with no application, and with application of 10 mg kg-1 Zn, applied as zinc sulfate. Shoot dry weight, grain yield, Zn harvest index, Zn concentration in shoot and in grain were significantly influenced by soil Zn levels and genotypes. However, panicle number and grain harvest index were significantly affected only by genotype. Genotypes CNA8557, CNA8540 and IR42 produced higher grain yield than other genotypes. Genotypes showed significant variability in Zn recovery efficiency. On average, 13% of the applied Zn was recovered by upland rice genotypes. Genotypes with high Zn recovery efficiency could be used in breeding of Zn efficient upland rice cultivars. Higher level of soil Zn (10 mg kg-1) increased significantly the concentrations of plant Cu and Mn. However, Fe concentrations in plant (shoot and grain) were not influenced by soil Zn levels.

Gas exchange rates, plant height, yield components, and productivity of upland rice as affected by plant regulators

The objective of this work was to evaluate gas exchange rates, plant height, yield components, and productivity of upland rice, as affected by type and application time of plant growth regulators. A randomized block design, in a 4x2 factorial arrangement, with four replicates was used. Treatments consisted of three growth regulators (mepiquat chloride, trinexapac-ethyl, and paclobutrazol), besides a control treatment applied at two different phenological stages: early tillering or panicle primordial differentiation. The experiment was performed under sprinkler-irrigated field conditions. Net CO2 assimilation, stomatal conductance, plant transpiration, and water-use efficiency were measured four times in Primavera upland rice cultivar, between booting and milky grain phenophases. Gas exchange rates were neither influenced by growth regulators nor by application time. There was, however, interaction between these factors on the other variables. Application of trinexapac-ethyl at both tillering and differentiation stages reduced plant height and negatively affected yield components and rice productivity. However, paclobutrazol and mepiquat chloride applied at tillering, reduced plant height without affecting rice yield. Mepiquat chloride acted as a growth stimulator when applied at the differentiation stage, and significantly increased plant height, panicle number, and grain yield of upland rice.

Tratamento estatístico dos parâmetros da qualidade das águas da bacia do alto curso do Rio das Velhas

Water quality was monitored at the upper course of the Rio das Velhas, a major tributary of the São Francisco basin located in the state of Minas Gerais, over an extension of 108 km from its source up to the limits with the Sabara district. Monitoring was done at 37 different sites over a period of 2 years (2003-2004) for 39 parameters. Multivariate statistical techniques were applied to interpret the large water-quality data set and to establish an optimal long-term monitoring network. Cluster analysis separated the sampling sites into groups of similarity, and also indicated the stations investigated for correlation and recommended to be removed from the monitoring network. Principal component analysis identified four components, which are responsible for the data structure explaining 80% of the total variance of the data. The principal parameters are characterized as due to mining activities and domestic sewage. Significant data reduction was achieved.

Characterization of the major nutritional components of Caryocar brasiliense fruit pulp by nmr spectroscopy

Pequi (Caryocar brasiliense Camb.), a typical fruit of Brazilian Cerrado, is well known in regional cookery and used in folk medicine to treat various illnesses. Mass spectrometry and chromatographic methods have identified the organic composition of pequi fruit pulp; however, NMR spectroscopy is used for the first time to characterize the nutritional components of organic and aqueous-ethanolic extracts. This spectroscopic technique determined the triacylglycerols in the pequi organic fraction, which is constituted mainly by oleate and palmitate esters, and detected the carbohydrate mixtures as the major components of aqueous and ethanolic fractions, respectively. In this study, presence of phenolic compounds was only evidenced in the ethanolic fraction.

In vitro activity of essential oils of Lippia sidoides and Lippia gracilis and their major chemical components against Thielaviopsis paradoxa, causal agent of stem bleeding in coconut palms

Essential oils of Lippia sidoides, Lippia gracilis and their main chemical components were investigated for in vitro control of Thielaviopsis paradoxa. Mycelial growth and a number of pathogen conidia were inhibited by the essential oil of L. sidoides at all concentrations tested (0.2; 0.5; 1.0; 3.0 µL mL-1). L. sidoides oil contained 42.33% thymol and 4.56% carvacrol, while L. gracilis oil contained 10% thymol and 41.7% carvacrol. Mycelial growth and conidial production of T. paradoxa were completely inhibited by thymol at a 0.3 µL m-1 concentration. The results suggest that thymol could potentially be used for controlling coconut stem bleeding.

Electron paramagnetic resonance (EPR) spectral components of spin-labeled lipids in saturated phospholipid bilayers: effect of cholesterol

Electron paramagnetic resonance (EPR) spectroscopy was used to study the main structural accommodations of spin labels in bilayers of saturated phosphatidylcholines with acyl chain lengths ranging from 16 to 22 carbon atoms. EPR spectra allowed the identification of two distinct spectral components in thermodynamic equilibrium at temperatures below and above the main phase transition. An accurate analysis of EPR spectra, using two fitting programs, enabled determination of the thermodynamic profile for these major probe accommodations. Focusing the analysis on two-component EPR spectra of a spin-labeled lipid, the influence of 40 mol % cholesterol in DPPC was studied.

VOLATILE COMPONENTS FROM GALLS INDUCED BY Baccharopelma dracunculifoliae(Hemiptera: Psyllidae) ON LEAVES OF Baccharis dracunculifolia(Asteraceae)

The volatile components of the galls induced by the insect Baccharopelma dracunculifoliae (Hemiptera: Psyllidae) on leaves of Baccharis dracunculifolia (Asteraceae) were analyzed by gas chromatography-mass spectrometry (GC-MS) and gas chromatographyflame- ionisation detection (GC-FID), and then comparison with volatile oil samples from healthy leaves collected in the vicinity. The galls produced around 3.5% of the total organic volatiles whereas healthy leaves rendered an average yield of 0.6%. The observed higher proportions of germacrene D, bicyclogermacrene, limonene, and β-pinene in the galls suggest that all these compounds are important targets in the search for natural enemies of this Psyllid. Moreover, higher relative percentages of (E)-nerolidol and spathulenol were found in healthy leaves.

MCR-ALS APLICADO NO MONITORAMENTO QUANTITATIVO DO PROCESSO DE ELETRODEGRADAÇÃO DA ATRAZINA USANDO ESPECTROS UV: RESULTADOS COMPARATIVOS COM HPLC-DAD COMO UM MÉTODO DE REFERÊNCIA

Electrodegradation of atrazine in water was performed using homemade (PA and PB) and purchased (PC) boron-doped diamond anodes. The degradation was monitored off-line by analyzing total organic carbon and high performance liquid chromatography with diode array detector (HPLC-DAD) and at-line by UV spectroscopy. The spectra were recorded every 2 min. The rank deficiency problem was resolved by assembling an augmented column-wise matrix. HPLC was employed to separate the original and byproducts degradation components. Aiming the same goal, multivariate curve resolution - alternating least squares (MCR-ALS) was applied to resolve the UV spectroscopic data. Comparison between HPLC and MCR-ALS separations is presented. By using MCR-ALS the spectra of atrazine and two byproducts were successfully resolved and the resulted concentration profiles properly represented the system studied. The ALS explained variance (R2) for PA, PB and PC was equal to 99.99% for all of them and the lack of fit for PA, PB and PC were 0.39, 0.34 and 0.54 respectively. The correlation (R) between the recovered and pure spectra were calculate for each electrodegradation, validating the MCR-ALS results. The average R was equal to 0.997. The spectral and concentration profiles described with this new approach are in agreement with HPLC-DAD results. The proposed method is an alternative to classical analyses for monitoring of the degradation process, mainly due to the simplicity, fast results and economy.

APPLICATION OF PARAFAC AND OPLS-DA ANALYSES ON HPLC FINGERPRINTS FOR THE CHARACTERIZATION OF Hibiscus sabdariffaCALYXES

The calyxes of Hibiscus sabdariffa are used in traditional medicine around the world. However, quality assurance protocols and chemical variability have not been previously analyzed. In the present study, chemical characterization of a set of samples of H. sabdariffa calyxes commercialized in Colombia was accomplished with the aim to explore the chemical variability among them. Chemometrics-based analyses on the data obtained from the HPLC-UV-DAD-derived profiles were then performed. Thus, the pre-processed single-wavelength data were subjected to principal component analysis (PCA). The PCA-derived results evidenced different groups which were well-correlated to the corresponding total phenolic and total anthocyanin contents. Multi-wavelength chromatographic (HPLC-UV-DAD surfaces) data were additionally examined via parallel factor analysis (PARAFAC) as data reduction method and the obtained loadings were subsequently submitted to PCA and orthogonal partial least squares discriminant analysis (OPLS-DA). Results were thus consistent with those from single-wavelength data. PCA loadings were employed to determine those chemical components responsible for the data variance and OPLS-DA model, constructed from PARAFAC loadings, and indicated differentiation according total anthocyanin contents among samples. The present chemometric analysis therefore demonstrated to be an excellent tool for differentiation of H. sabdariffacalyxes according to their chemical composition.

REDUÇÃO DE VARIÁVEIS DE ENTRADA DE REDES NEURAIS ARTIFICIAIS A PARTIR DE DADOS DE ANÁLISE DE COMPONENTES PRINCIPAIS NA MODELAGEM DE OXIGÊNIO DISSOLVIDO

The objective of this work is to demonstrate the efficient utilization of the Principal Components Analysis (PCA) as a method to pre-process the original multivariate data, that is rewrite in a new matrix with principal components sorted by it's accumulated variance. The Artificial Neural Network (ANN) with backpropagation algorithm is trained, using this pre-processed data set derived from the PCA method, representing 90.02% of accumulated variance of the original data, as input. The training goal is modeling Dissolved Oxygen using information of other physical and chemical parameters. The water samples used in the experiments are gathered from the Paraíba do Sul River in São Paulo State, Brazil. The smallest Mean Square Errors (MSE) is used to compare the results of the different architectures and choose the best. The utilization of this method allowed the reduction of more than 20% of the input data, which contributed directly for the shorting time and computational effort in the ANN training.

JUVENILE-MATURE GENETIC CORRELATIONS IN Pinus taeda CLONES PROPAGATED VIA SOMATIC EMBRYOGENESIS

ABSTRACT This study aimed to estimate the genetic correlation among selection ages (juvenile - adult) and efficiency of early selection for the height, diameter, and volume traits of individuals from Pinus taeda families propagated via somatic embryogenesis. This study was carried out by genetic-statistical analysis, estimation procedure of variance (Reml), and prediction components of breeding values (Blup), using the Selegen-Reml/Blup software. Genetic correlations among juvenile ages and rotation age were performed by applying the linear model developed by Lambeth (1980). In accordance with results of the established model, the early selection can be performed in clones of Pinus taeda with high selection efficiency. Ages from 4 to 6 years old are enough to select Pinus taeda clones propagated via somatic embryogenesis for harvesting at 8 and 12 years old; and 6 to 10 years old are enough to select them for harvesting at 20 years old. On the basis of the genetic correlations estimates from the environments, the clones' selection of Pinus taeda propagated via somatic embryogenesis should be developed specifically for each environment. The clones' selection can be performed considering the diameter due to the high correlation between volume and diameter.