Do Aqueous Extracts from Buckwheat Compromise Seed Germination and Initial Development of Bidens pilosa and Euphorbia heterophylla?

Fagopyrum esculentum Moench (buckwheat) is a dicot species from the Polygonaceae family used as a cover crop in agricultural systems featured with a remarkable allelopathic potential for weed control, helping herbicide-resistance management and promoting substantial reductions in herbicide applications. The aim of this research was to examine the allelopathic potential of aqueous extracts from seeds and aerial part of buckwheat on seed germination and initial development of Bidens pilosa and Euphorbia heterophylla. Bioassay experiments were conducted under a completely randomized experimental design with four replications, containing 50 seeds each. Both weed seed species were harvested in a soybean field, and seed viability was previously assessed. Seeds were exposed to four concentrations (0, 25, 50, and 100%) from extracts of seeds (ES) and aerial part (EAP) of buckwheat. Germination speed index (GSI) in B. pilosa and E. heterophylla was daily evaluated throughout 14 and 16 days, respectively, whereas percentage of germination, abnormal seedlings, as well as non-germinated seeds, root (RL) and aerial part length (APL), and total dry matter (TDM) were rated at final germination test. EAP reduced the GSI, especially under the 100% concentration. Germination percentage was lower and abnormal seedlings increased for both weed species when seeds were exposed to EAP concentrations greater than 25%. However, ES did not impinge upon E. heterophylla germination. EAP and ES reduced the APL, RL, and TDM for concentrations greater than 50%, except for ES which did not affect E. heterophylla development. Both extracts from buckwheat have a high capacity to inhibit germination and compromise seedling development, culminating in such a potential alternative for B. pilosa and E. heterophylla management in agricultural systems.

Impact of Fungicide Spray Timings on Foliar Diseases Control in Wheat Cultivars

Wheat (Triticum aestivum L.) is grown throughout the winter time in Southern Brazil and turns out to be the main agricultural crop at such a year season in the State of Paraná. However, throughout the crop growing season foliar diseases significantly compromise commercial yields in such a manner as to justify the application of fungicides at the right time to control foliar diseases in production fields. The aim of the current manuscript was to assess the impact of different timings for fungicide application (epoxiconazole + pyraclostrobin) on the control of leaf rust (Puccinia triticina E.) and yellow spot (Pyrenophora tritici-repentis) diseases in two wheat genotypes featured by distinct levels of susceptibility in Southern Brazil. A field trial was conducted in Ponta Grossa, State of Paraná, Brazil, in light of split plot statistical design at an experimental area belonging to CESCAGE. The following treatments were imposed in the current study: control (with no sprays);sprays at the first node, booting and heading;sprays at stem extension and flowering;sprays at booting and heading. Throughout the entire crop growing season, the control treatment was conducive to the highest severity levels for both diseases. The increasing of the area under the diseases progress curve assessed herein substantially impinged upon yield components of both wheat genotypes under scrutiny. In general, fungicide sprays at the first node did not culminate in economical advantages. The best timing for fungicide application was the one ascribed to booting and heading stages.

Phenolic Compounds and Antioxidant Capacity of Brazilian Apples

Apple consumption is related to the prevention of chronic diseases due to the presence of phenolic acids and flavonoids that have antioxidant capacity. However, phenolic profile and antioxidant capacity can vary between varieties. The aim of this study was to analyze the total phenolic content (TPC) and antioxidant capacity (AC) of thirty-six apple varieties to establish a classification of these fruits. The TPC was analyzed according to the Folin-Ciocalteau method and AC was analyzed using the ferric reducing antioxidant power (FRAP) method. Hierarchical cluster analysis was used for the classification of the fruit. The TPC ranged from 456 to 1583 mg/kg of fresh fruit (catechin equivalents) and the AC ranged from 5606 to 23,719 mmol/kg (fresh fruit). The Pearson linear correlation showed significant differences in the association between TPC and AC (r: 0.79, p < 0.001). The apples were classified into the following five groups according to their AC: very high (8%), high (17%), medium (47%), low (11%) and very low (17%). The varieties classified in the group with very high AC were Carícia, Mollies and Imperatriz. The Gala varieties showed a great variability in AC, with values classified as high and low, while the Fuji, with less variability, was classified as low AC. The classification of apples based on TPC and AC using hierarchical cluster analysis was performed and the results can be of great value to geneticists, producers and consumers.

Field Comparison of Soil Moisture Sensing Using Neutron Thermalization, Frequency Domain, Tensiometer, and Granular Matrix Sensor Devices: Relevance to Precision Irrigation

The efficient use of irrigation water requires several kinds of information. One element of efficient irrigation scheduling is monitoring the soil moisture to assure that the crop irrigation goals are being met. Various soil moisture sensing devices were tested for irrigation scheduling in silt loam at the Malheur Agricultural Experiment Station, Oregon State University between 2001 and 2004. Neutron probes, frequency domain probes, tensiometers, granular matrix sensors, and Irrigas were compared as to their performance under field conditions at Ontario, Oregon, USA. Granular matrix sensors were tested as read automatically by a datalogger and read manually with a hand-held meter. Practical suggestions are provided to use soil moisture sensors to the benefit of crop production and water conservation.

Economic Feasibility of Canola Production in the Region of Campos Gerais, Paraná, Brazil

This study aimed to analyze the economic feasibility of canola production (Brassica napus var oleifera) for the region Campos Gerais-PR. We interviewed eight producers, and used information from four of them for economic analysis of agricultural crops in 2012, 2013 and 2014. The variables analyzed were: grain production cost, economical analysis (hurdle rate, net present value, internal rate of return, payback, lucratively index, profitability index and sensitivity analysis) and vegetable oil production costs. We compared the performance of canola, wheat (Triticum aestivum)—as the main crop in the autumn/winter—and soybean (Glycine max)—by liquidity in the world market. It was concluded that although the economic analysis indicates superior results of canola production compared to the wheat crop and vegetable oil production is more attractive financially than soybean, but the culture of canola is still insignificant in the region of Campos Gerais (PR). The producers interviewed pointed to limit the expansion of culture financing the limited farming, production technology in consolidation, the need for machine adjustments and canola be host of the white mold disease (Sclerotinia sclerotiorun).

The Alumina Film Nanomorphology Formed to Improve the Corrosion Resistance of Al-2.0 wt% Fe Alloy as Result of the Laser Surface Melting Technique Applied

The laser surface remelting (LSR) treatment was performed to Al-2.0 wt% Fe alloy with a 2 kW Yb-fiber laser (IPG YLR-2000S). The substrate and laser-treated material characterization were executed using different techniques. Among them, the microstructure was analyzed by optical microscope, SEM, low-angle X-ray diffraction (LAXRD) and the corrosion test was made in aerated solution of 0.1 M H2SO4 at a temperature of 25°C ± 0.5°C. As result was shown, the micrograph of LSR-treated material displaying can be a fine cellular structure and the existence of certain nano-porosities and a similar to a nano-dendritic growth was observed too. The characteristic of melted zone was constituted of metastable phases according to the result of x-rays and the behavior corrosion as a result of the LSR-treated sample, which it was shown to be more resistant to corrosion than the untreated sample. A comparative study was carried out of the cyclic polarization of the laser-treated and untreated samples, demonstrating that the reduction and oxidation reverse peaks were not observed and being the cyclic polarization behavior was of irreversible character in both samples, however, the LSR-treated sample propitious the passivity on the surface also reduced the corrosion phenomena. Wherefore, this type of laser-treated alloy can be applied in the aerospace, aeronautic and automobilist industries.

Applicability Evaluation of a Laser Light-Mater Interaction Based Computational Tool on Status Identification of Applied Micro-Structured Coatings

The current work aims at evaluating a proposed method based on a computational tool developed using Object-Oriented Programming to identify the status of micro-structured surfaces. In this case, these are micro-structured coatings with riblet microstructure developed by Fraunhofer Institute–IFAM, by building a graphical reproduction of the analyzed surface and calculating an expected laser reflection intensity acquired by a laser sensor device, the proposed method is assessed by using the simplest case: a flat surface, and an optimal case: an intact riblet surface. The results corroborate the calculations to be applied to further steps from more complex cases of degradation and to diverse riblets geometries. Based on Huygens-Fresnel and Fraunhofer diffraction theories, the calculations developed and demonstrated in this paper improved the nondestructive tests to support the status identification of the micro structured coatings, e.g. riblet structures based on shark skin used in shipping and aerospace industries. This work is assured required quality of the riblet coating identifying the number of structures and expected geometry using implemented calculations to foresee the laser reflection intensity acquired by a laser sensor device with 3 detectors, for instance, a riblet structure could be graphically reproduced, analyzed and completely identified based on the application of the theoretical optics applied on this work.

Water Quality and the Impact by Contaminants of Emerging Concern: The Case of Verde River in Campos Gerais

In this article, we report the results of the work carried out on the Verde River, a predominantly urban river located in the city of Ponta Grossa, Paraná, Brazil. Developed in three stages, it aimed to evaluate the water quality through physical-chemical parameters, the presence of caffeine as a chemical tracer, and the compound Triclosan (TCS), considered a pollutant of emerging concern. An attempt was made to identify possible polluting sources along the river. Samples were collected at 4 points from the spring region, with sampling upstream and downstream of a Sewage Treatment Plant (STP). The physical-chemical parameters were determined in situ, through portable analysers, as well as in the laboratory, in this case, through analyses using molecular absorption spectroscopy. For the determination of TCS and Caffeine, high-performance liquid chromatography (HPLC) was used, preceded by a pre-concentration step in the solid phase (SPE), and the techniques were implemented after validation. The physicochemical evaluations of the surface samples showed a decline in water quality after the STP. Mean total phosphorus concentrations of 1.0 mg·L-1 (±0.4), as well as dissolved oxygen (DO) levels below 5.0 mg·L-1 were verified downstream of the STP. Caffeine concentrations for Verde River were between 49.0 to 299.0 μg·L-1, verified upstream and downstream of the STP. The results demonstrated the relationship between the presence of caffeine and impaction, either by the input of raw sewage or by treated effluent. TCS was detected by chromatographic analysis, downstream of the STP, with an average concentration of 27.6 (±1.7) μg·L-1, noting that its presence was associated with the reactor maintenance procedure, with the STP in the process called bypass. Obtaining quality data from Verde River is important for the protection of the environment and affects the health of the population.

Pyrolysis of Banana and Coffee Residues after Acid Hydrolysis

The use of the residues from renewable feedstock, besides the production of fuels, but also for the generation of other chemicals products, has become a priority. Superior plants have considerable potential as carbohydrate, aryl and fatty acids sources. However, the separation of the main constituents of the samples is necessary for several purposes in the biorefinery concept. The acid hydrolysis and pyrolysis processes are very promising technology, however, some adjustments in the conditions of pyrolysis are needed for different biomasses since carbohydrates were detected （14%-17%） in the residues after the conventional acid hydrolysis of these uncommon biomasses （coffee husk and banana stem and stalk）. On the other hand, it was showed that, by pyrolysis, it is possible to obtain from the solid residue after acid hydrolysis： pyrogenic carbon （charcoal with a yield of 48.5%-52.7%） for agriculture use （biochar） and valuable chemicals in the pyrolysis oil biooil fraction （that accounted by 26.4%-29.0%, free of water）, such as lignin monomers （32.6%-56.4% of the bio-oil） and fatty acids （30%-52.5%）.

Effects of Climate and Agricultural Practices on Temporal Progress of Sclerotinia sclerotiorum for Soybean in Brazil

Currently the soybean crop is affected by the white mold (Sclerotinia sclerotiorum). The disease can reduce the crop yield and quality and decrease the prices of agricultural lands. The aim of the current research was to assess epidemiology of white mold on soybean crop grown at Arapoti, PR, Brazil, utilizing data related to agricultural practices and local meteorological factors. The experiment was conducted in a naturally infested area. The soybean crop was sown on October 18th, 2011. The experimental design adopted herein was a randomized block in a factorial combination with 4 row spacings (0.35, 0.45, 0.60, 0.75 m) and 4 plant populations (150, 200, 250, 300 thousand plants per hectare) and 4 replications. The temporal analysis of the epidemic was evaluated using mathematical models, such as Logistics, Monomolecular and Gompertz, in order to determine the best model that described the progress of the disease as a function of local meteorological elements. For the incidence data it has been shown that both logistic and monomolecular models were those that were best fitted to the experimental data. For severity, the best model related to the experimental data was the logistic one. Either for incidence or for severity, air temperature was considered to be the environmental factor most affecting the progress of the disease. The variability in the apparent infection rates of white mold on soybean was not affected by different row spacings and plant populations;therefore, suggesting that macroclimatic variations prevailed in such a fashion to mitigate the effect of cultural practices adopted in the field.

Understanding of Socially Vulnerable Individuals on Oral Health and Access to Dentist: A Brazilian Study

Social vulnerability experienced by collectors of recyclable materials has a strong influence on their understanding and confrontations health. This research aimed to explore the relationship between oral health and perception of subjects in a context of social disadvantage, in order to support concrete alternatives for action on (oral) health conference. This was a qualitative study carried out with representatives of an autonomous community of Brazilian collectors of recyclable materials. Data were collected through interviews and focus group treated with the technique of qualitative analysis. Respondents showed perceptions of etiology and care practices on oral health promoted beliefs and values collectively instituted in a social risk territory. Also, they associate the quality of their oral health and their difficulty of public access to the context of social vulnerability. This study suggests the adoption of protective, educational and interceptive in oral health practice in order to improve and enable the oral health status of this population.

Spacing between Soybean Rows

The soybean crop has great economical importance in Brazil and in the world. In order to make the crop production profitable, several factors must be considered. The objective of this study was to evaluate the impact of spacing between soybean crop rows (Glycine max). The experiment was installed in the Mutuca farm (Arapoti—PR, southern Brazil), in the crop seasons of 2012/2013 (four seeding seasons) and 2013/2014 (two seeding seasons), in a completely randomized blocks design. We used four treatments and six replicates. The treatments were the spacing between rows as follow: 0.25, 0.50, 0.75 and 1.00 m. The variables evaluated were: initial and final plant population, plant height, number of internodes, viable internodes, pods per plant, grains per pod, mass of thousand grains and crop productivity. We concluded that the reduction of the spacing between rows significantly increased, in most part of the crop seasons, the number of pods per plants and the crop productivity.

Agrometeorological and Soil Criteria for Defining Workable Days for Rational Mechanized Sugarcane Harvest in Southern Brazil

The number workable days (NWD) for agricultural field operations is of great importance for sizing agricultural machinery fleets. This is especially pivotal for sugarcane harvest, which extends from 8 to 10 months/year. In light of this, the current study aimed at defining criteria for obtaining the NWD for rational sugarcane harvest at different sites in the state of S&#227;o Paulo, southern Brazil, taking into account both a general and a specific criteria. For this purpose, data from harvest interruption of 30 sugar mills in southern Brazil throughout periods ranging from two to five years were used. The following variables were tested as criteria for defining harvest interruption: minimum precipitation (PREC);soil water holding capacity (SWHC);and the limit of the ratio between actual soil moisture (SM) and SWHC. Based on such a specific criterion ascribed to each site along with a general criterion, NWD maps were prepared for the state of S&#227;o Paulo, Brazil. The results showed that there were variations from the definition criteria of NWD at the different sites in the state. However, the use of a general criterion for harvest interruption, based on PREC ≥ 3 mm, SWHC = 40 mm and SM/SWHC ≥ 90%, provided accurate results. During the validation of these criteria, the NWD maps generated from the individual criterion proposed for each site resulted in an average error of 24.9 days/year, whereas the map generated from the general criterion culminated in an average error of 4.4 days/year.

Soil Pore Characterization Using Free Software and a Portable Optical Microscope

Total porosity （TP）, determined by image analysis, pore type and pore size distribution were evaluated on impregnated soil blocks from an undisturbed Brazilian sandy loam soil using a digital portable optical microscope. The free software Image J （version 1.40g） was used for image analysis. Procedures for soil image collection and analysis were presented. The image analysis allowed the evaluation of pore sizes with diameters ranging from 20 to 〉 1 000 μm. The following types of pores were also obtained： rounded, elongated and intermediate. The results M[owed the characterization of the soil as moderately porous （TP = 21.6%）. Rounded, intermediate and elongated pores were responsible for 11.6%, 31.7% and 56.7% of TP. In relation to pore size 51.1% of TP was in the 100-500μm size class and a third of TP came from the pores larger than 500μm.

Down-and up-conversion processes in Nd^(3+)/Yb^(3+)co-doped sodium calcium silicate glasses with concomitant Yb^(2+)assessment

Novel Nd^(3+)/Yb^(3+)co-doped sodium calcium silicate glasses were prepared by melting quenching method:Spectroscopic study was carried out as a function of doping content by fixing sensitizer(Nd^(3+))concentration to 0.2 mol%and adjusting activator(Yb^(3+))from 0 to 1.0 mol%.The energy transfer(ET)mechanisms between Nd^(3+)and Yb^(3+)are discussed based on their energy levels and excitation powerdependence emission intensity.Results show that the presence of Yb^(2+)might be considered for the Nd^(3+)-free and co-doped samples.The ET was confirmed by the down-conversion NIR emission spectra of the doped and co-doped samples under excitation at 808 nm.The mechanisms observed seem to involve only one VIS absorbed photon for each NIR emitted via direct energy transfer between^(4)F_(3/2)of Nd^(2+)and^(2)F_(5/2)of Yb^(3+)compensated by phonon assistance due to energy gap between these levels.The efficiency of ET increases with the ytterbium content up to almost 90%for the sample with 1 mol%of Yb2O3,which was evaluated by lifetime measurements.Up-conversion photoluminescence by exciting trivalent ions of neodymium(808 nm)and ytterbium(975 nm)is reported.The observed up-converted emission bands are related to the 4f-4f transitions of Nd^(3+)and the spin-forbidden 5d-4f transition of Yb^(2+).Nd^(3+)upconversion emission is observed under 975 nm excitation,presenting an almost quadratic emission dependence with power excitation,which suggests that two laser photons participate in the up-conversion(UC)process,showing that ET occurs by a phonon-assisted energy transfer and cooperative energy transfer.

Optimizing Nitrogen Use Efficiency for No-Till Corn Production by Improving Root Growth and Capturing NO_(3)-N in Subsoil

Subsoil acidity restricts root growth and reduces crop yields in many parts of the world. More than half of the fertilizer nitrogen(N) applied in crop production is currently lost to the environment. This study aimed to investigate the effect of gypsum application on the efficiency of N fertilizer in no-till corn(Zea mays L.) production in southern Brazil. A field experiment examined the effects of surface-applied gypsum(0, 5, 10, and 15 Mg ha^(-1)) and top-dressed ammonium nitrate(NH_4NO_3)(60, 120, and 180 kg N ha^(-1)) on corn root length, N uptake, and grain yield. A greenhouse experiment was conducted using undisturbed soil columns collected from the field experiment site to evaluate NO_3-N leaching, N uptake, and root length with surface-applied gypsum(0 and 10 Mg ha^(-1)) and top-dressed NH_4NO_3(0 and 180 kg N ha^(-1)). Amelioration of subsoil acidity due to gypsum application increased corn root growth,N uptake, grain yield, and N use efficiency. Applying gypsum to the soil surface increased corn grain yield by 19%–38% and partial factor productivity of N(PFPN) by 27%–38%, depending on the N application rate. Results of the undisturbed soil column greenhouse experiment showed that improvement of N use efficiency by gypsum application was due to the higher N uptake from NO_3-N in the subsoil as a result of increased corn root length. Our results suggest that ameliorating subsoil acidity with gypsum in a no-till corn system could increase N use efficiency, improve grain yield, and reduce environmental risks due to NO_3-N leaching.

Nitrogen fertilization and potassium requirement for cereal crops under a continuous no-till system

Nitrogen(N)and potassium(K)are the most required nutrients for corn and wheat production.Increasing the N application rate usually boosts crop yields.However,many uncertainties remain for K management.Potassium deficiency results in yield losses,but K application rate based on the percentage of K+in the cation exchange capacity(CEC)is doubtful,especially in soil with high CEC.A field trial was conducted to examine the effects of KCl application before sowing corn and wheat,by raising the percentage of K+in CEC at pH 7.0(CECpH7.0)to approximately 2.5%,3.5%,and 4.5%,and adding N as a topdressing(75,150,and 225 kg ha-1 to corn and 40,80,and 120 kg ha-1 to wheat)on the nutrition and yield of corn and wheat under a continuous no-till system(30 years).Exchangeable K+content increased in the topsoil(0–20 cm depth)up to 7.2 mmolc dm-3 after K application at the highest rate,which,however,did not result in significant increases in nutrient uptake and yields for both corn and wheat.The N application rate positively affected the uptake and removal of all macronutrients by corn and wheat.Applying N as a topdressing increased yields of corn and wheat by up to 83%and 22%,respectively.Our results suggest that in the soil with a high CECpH7.0(162.1 mmolc dm-3),the recommendation for K application made by considering the percentage of K+in the CECpH7.0 may result in excessive application of K fertilizer to crops with high K-recycling potential grown under a continuous no-till system.