Repositório RCAAP

O objetivo deste trabalho foi avaliar a variabilidade de características agronômicas de uma população de trevo vermelho (Trifolium pratense L.) tais como: taxa de crescimento em altura nos períodos vegetativo e reprodutivo, taxa de crescimento em diâmetro no períodos vegetativo e reprodutivo, rendimento de matéria seca por planta, produção de sementes e seus componentes (hastes/planta, inflorescências/plant

The main objective of this study was to develop a freely available mobile software application and education platform in health and safety for aquaculture workers and managers.  The application, called AquaSafe, was created in Portuguese and English for the Android system using the Java 8 programming language and the Android Studio development environment. AquaSafe content focusses on the identification of hazards and health risks, hazardous sources and preventive measures for occupational health and safety in the aquaculture sector. It has three predominantly interactive user interfaces to reinforce the main messages, which include games in the form of compliance checklists, quizzes and question-answer tools. The software is designed to act as a platform for assessment and management of occupational hazards, guide decision making on simple techniques or measures to prevent injuries, diseases and fatalities during aquaculture activities. It is envisaged that the AquaSafe mobile software will contribute to the prevention of occupational injuries and diseases in aquaculture.

Four trials in randomized complete blocks design were carried out in the Laboratory of Centro de Pesquisa para Pequenas Propriedades, of Empresa de Pesquisa Agropecuária e Extensão Rural de Santa Catarina, Chapecó, western Santa Catarina, Brazi I, to study repellent and toxic products to Sarasinula linguaeformis (Semper, 1885) (Mollusca, Veronicellidae). Repellents tested were: copper sulfate 2%, creolin 2%, ammoniac salt 2%,and sodium hydroxide 0.125%, sprayed on the leaves of cabbage used for feeding the slugs. The evaluation was done 96 hours after measuring the remains of the food. The toxicity of different products were tested with: sodium hydroxide 2%, copper sulfate 2%, tobacco extract 3%, detergent 3%, slugs extract 10%, creolin 2%, ammoniac disinfectant 3%, kerosene 3%, ammoniac salt 2%, sodium chloride 3% and 5%, and urea 3%, sprayed directly on the slugs. The mortality of the slugs was evaluated 24; 48 and 72 hours after spraying. The best repellent was copper sulfate. The most toxic products were sodium hydroxide, kerosene, creolin, and ammoniac salt.

The present study aimed to identify some common techniques of management which may affect the experimental error of competition assays in com, soybean, rice, wheat, bean and oat. A total of 1920 assays were developed in Rio Grande do Sul State, from 1987 to 1995. For each crop, the assays were grouped based on similarity of management. For each new group the value of the mean square of the average error was calculated, considering the error degrees of freedom. These values were used to apply F test to compare two variations. The effects of crop management on the experimental error were analyzed based on comparisons among specific groups. It can be concluded that seeds treatment in soybean and wheat, com trimming, use of pre-germinated seeds in rice, insect and weed control in soybean reduce the experimental error, generally. On the other hand, cover fertilizer application in soybean, and insect control in com and wheat usually increase the experimental error.

The use of mean separation tests is one of the alternatives to compare treatments, when the factors are qualitative and not structured. This paper had the objective to evaluate the use of mean separation tests in oat trials and to discuss the advantages of application of more appropriate statistical procedures. The data analyzed were published in the annals of "Reunião da Comissão Brasileira de Pesquisa de Aveia" (Meeting of Oat Research Brazilian Committee), from 1996 to 1998. The published papers were classified as follows: appropriate, partially appropriate and inappropriate, concerning its use. The conclusions regarding the oat trials were encouraging. More than 80% of the papers that presented mean separation tests were properly applied, with a tendency to increase in the evaluated years. The mean separation tests applied inadequately represented 10% (in average) of analyzed papers, where the most frequent error was to apply these tests to compare levels of quantitative factors. The incorrect use of mean separation tests does not imply, necessarily, in erroneous conclusions. However, it may limit the inferences that could be made on the obtained data.

Disease resistance, at seedling stage, has been widely used in breeding programs because it is easier to recognize and select. However, the adult-plant resistance (APR) can be used to increase the durability of resistance. An experiment was carried with the cultivars Rio Negro, Rio Tibagi, Diamante Negro, Pérola, Xamego and Aporé, with the objective of identifying APR. Six successive planting dates of these cultivars were madc at seven-day intervals and inoculation with four pathotypes of Colletotrichum lindemuthianum. APR was observed in the cultivars Rio Negro and Rio Tibagi. However, a seedling resistance interferente in the latter was observed. Although the susceptible cultivars Diamante Negro and Pérola showed reduction in symptoms intensity with increase of age, they did not achieve the resistance level of 'Rio Negro' and 'Rio Tibagi'. The cultivars Aporé and Xamego showed seedling resistance to alI four isolates of the pathogen tested.

The objective of this study was to evaluate the effect of three methods of soil tillage (conventional, reduced and no-tillage), three crop systems (oats/ com, oats + clover/ com, and oats + clover/ com + cowpea) and two rates of nitrogen (0 and 120 kg/ha) on the accumulation of crop residues on the soil surface, com nutrition and yield. The accumulated crop residues on the soil surface, evaluated at the end of the year, varied from 3.09 to 5.60 t/ha of dry matter, and it was not affected by soil tillage, crop systems and N rates. The nitrogen was the most limiting nutrient to the com yield, and its availability was lower in no-till lago, as compared with conventional tillage. However the com yield was not affected by tillage methods and it varied from 2.39 to 5.72 t/ha. Without N application, use of legumes as green manure-cover crops increased com yield up to 81% and it was correlated with total amounts of N in the biomass on the soil surface (residues plus winter crops). The conservation management systems, that associate no-tillage or reduced tillage, and legumes for cover and N addition, resulted in relatively high com yields. In addition, they have benefits due to soil cover crop residues during a larger period of the year, compared with conventional soil management systems.

Among bacterial diseases that affect dry beans, common bacterial blight, caused by Xanthomonas axonopodis pv. phaseoli, can considerably reduce grain yield of this crop and is the most important in Brazil. Genetic resistance is one important characteristic to be considered in the integrated disease management during the development of new dry bean cultivars. The objective of the present research was to obtain dry bean lines resistant to common bacterial blight using the single seed descent method. Thirty lines resistant to common bacterial blight were obtained with considerable reduction in generation advance time.

Seed germination is basic to good pasture implantation. The objective of this work was to evaluate germination ability of Paspalum notatum Flügge var. notatum seeds, ecotype André da Rocha, under distinct storage conditions: storage at 5° C in refrigerator, or in laboratory conditions. Sceds were submitted to the standard germination test and two methodologies to break dormancy: 1) imbibition in potassium nitrate (0,2 %); 2) manual scarification of the caryopsis. A split-plot experimental design was used with four replications of 50 seeds, for each storage condition and treatment. Storage conditions were treated as plots, and treatments as subplots. There were no differences in seed germination, regarding storage conditions and treatments to break dormancy (P>0,05). The KNO 3 treatment was the most efficient in breaking dormancy of seeds.

The objective of this study was to evaluate the efficiency of baits formulated with boric acid to control Sarasinula linguaeformis (Semper, 1885) (Mollusca, Veronicellidae). The trial, in randomized complete design with nine treatments and five replications, was carried out in laboratory of Centro de Pesquisa para Pequenas Propriedades, EPAGRI (Empresa de Pesquisa Agropecuária e Extensão Rural de Santa Catarina), Chapecó, westem Santa Catarina, Brazil. Each plot consisted of three slugs inside boxes (gearbox). The treatments, baits formulated with a mix of boric acid (different percents), wheat and com flour and eggs, were efficient in the attractiveness and control of the slugs, mainly at the rates of 2,0; 3,0; 5,0 and 10,0 %, with mortality between 99,46 and 100 %, up to 72 hours after the baits supply.

The mito Dichopelmus notus (Acari, Eriophyidae) causes tan and fali of leaves in mate tree. The treatments: canopy thirds (upper, medium and lower) and depth inside canopy (internal and external) were arranged in randomized blocks with a factorial design, with ten replications (trees), and were performed in an orchard in Chapecó, Santa Catarina to propose a sampling plan for Dichopelmus. Each plot consisted of one tree. Samples of three leaves per treatment were collected every two weeks from February through May 1999, per treatment. The number of mites/1 cm2 of each leaf was counted at laboratory. Through the modal, an estimator of the overall mean variance and the variances associated with random effects was obtained. The number of trees (10 and the number of leaves (L) were obtained by the combination of KxL, timing the variance of the mean at a minimum level. Results indicate that it is necessary to examine three internal leaves from inferior or medium thirds on a minimum of 110 trees.

The soil microbial biomass is of paramount importance for the understanding of the organic matter combover, nutrient cycling and energy flux in the soil. The most widespread and correlated methods are direct microscopy for fluorescent stained microorganisms (Biovolume), the chemical methods (ATP=adenosine triphosphate and fumigation-extraction—FE), and the physiological methods (fumigation-incubation=FI and substrate induced respiration—SIR). The biovolume method is rather subjective and time consuming, while the chemical and physiological methods are of better reproducibility and applied to a wider range of soils. For lowland soils, the methods tested are basically the same as for upland soils. The data available show that the FE and modified versions of Fl and SIR have a satisfactory performance, but the original ATP method seems to be unsuitable. The expression usually found in the literature does not refer to the total microbial biomass, but rather to specific components of the biomass I like C, N and ninhydrin reactive nitrogen. For the forthcoming years, significant increase in research is expected involving ATP, SIR, Fl and FE methods in organic matter turnover and energy cycling. The flourishing methods for biomass assessment of particular groups of microorganisms as well as the molecular techniques for the identification of individual components of the biomass are also expected to become more popular.

Virulence of 24 strains of Pasteurella multocida, 13 isolated from pleuritic and pneumonic pig lungs, and 11 from pig lungs obtained from abattoirs was studied. P multocida was cultured in BHI medium incubated at 37° C for 18 h and the number of colony forming units (C FU/ml) determined by inoculation of decimal dilutions on blood agar plates. Dilutions from 10 4 to 10.13 (8,3 x 10 15 to 1 CFU) were inoculated intraperitoneally in mice and the number of deaths for each dilution determined over a 7-day period. Each inoculated strain was recovered from at least two mice. LD50 were determined by the Spearman- Kãrber method. It was observed a wide variation in LD50, ranging from <1 to 10 10.2 CFU. There was no difference in virulence among strains from clinical cases or from abattoir lungs.

The high sensibility of maize crops to water deficits, mainly during the flowering period, makes necessary precise data in terms of water necessity, for several purposes of applications. With the objective to quantify the evapotranspiration throughout the maize crop cycle, at different atmospheric conditions, a field experiment was carried out from 1993/94 to 1996/97, at the Estação Experimental Agronômica of UFRGS, in Eldorado do Sul, Brazil. It was used an early hybrid (Pioneer 3230), sowed at the end of October, in a stand of around 67 thousands plants per hectare. The crop maize maximum evapotranspiration was measured in a weighing lysimeter, located in the center of a 0,54ha homogeneously cropped area. An average ETm of 656mm for the entire crop cycle was obtained, ranging from 575 to 732mm during the four-years period. This variation was attributed, mainly, to differences in the atmospheric evaporative demand. Variations in ETm throughout the crop cycle were also observed in a similar pattern, with minimum values at the beginning of the plant growth, increasing according to the leaf area index, up to maximum values during the flowering stages, and decreasing at the end of the crop cycle. 

 A study was conducted in greenhouse to evaluate the effect of different flooding periods on water utilization, nutrient uptake, and growth of the soybean plant in a soil of Guaiba series (Ultisol). The treatments consisted in flooding for 5, 10, 20, and 26 days, started when the plants presented three developed trifoliolate leaves, and compared to the soil water content at the field capacity. The treatment of flooding for 26 days ended when the plants showed the first flower. Soybean water consumption per unit of dry matter weight increased with the flooding duration, reducing the efficiency of water usage by the plants. Flooding reduced the water intake, dry matter weight, and plant height as well. The amount of roots increased due to the secondary root development, a reaction to low oxygen availability in the flooding condition. The P, K, Ca, Mg, and Mn content in the plant tissue decreased with the flood duration, whereas high Fe content was detected as a result of flood until the beginning of flowering. 

This research was carried out in a citrus nursery of orange 'Valência' to study the effect of products to control the citrus leafminer, Phyllocnistis citrella. The products (active ingredient) and amounts of commercial product/100 I water, were: imidachloprid (150 g), Bacillus thuringiensis (200 g), lufenuron (75 ml), abamectin + mineral oil (25 ml + 250 ml), fention (100 ml), and a check. The statistical design was a randomized block, with six treatments and four replications. Each treatment consisted of 20 plants (five in each block), and 10 leaves per plant were collected. The treatments were evaluated 7 and 14 days afta product application. The most efficient products were: imidachloprid, lufenuron and abamectin + mineral oil; Bacillus thuringiensis presented moderate control and fention was not efficient.

The experiment started in 1987 and finished in 1.990; was carried out at Estação Experimental Agronômica, Universidade federal do Rio Grande do Sul, located in Eldorado do Sul, Rio Grande do Sul —Brazil (30° 05' S, 5l"40' W). The orchard was established in 1976 and the main objective of the experiment was to evaluate fruit yield and quality of 'Valência' orange submitted to six spray fertilization treatments, with ultimate suppression of magnesium, manganese, zinc and boron. The experimental design was in randomized blocks, with five replications. Results did not show any effect on fruit yield, but there were significant effects on fruit quality. The fertilization increased the concentration of boron, manganese, and zinc in the leaaves.

The effect of Brachiaria brizantha on leaf arca and biomass production of Eucalyptus citriodora and E. grandisseedlings, grown in soils with different water contents, was evaluated under greenhouse conditions. Treatments were arrangedin factorial design, with four replications (2x3x4): two species of eucalyptus (E. citriodora and E. grandis), three watercontents (20, 23 and 26% mass), and four B. brizantha populations (0, 1, 2, 3 plants per pot). Moisture content in the potswas maintained constant until experiment harvest, 70 days after seedlings transplanting. B. brizantha showed a negativeinfluente on E. citriodora and E. grandis seedlings developent, when grown in the three water contents. However, there wasa higher effect when growth was under the best water conditions (26%), especially in presence of two to three plants of B.brizantha. E. citriodora was more sensitive to the interaction of water content and B. brizantha populations.

Presence of native forest showed a detrimental effect on the colonization and distribution of Anastrepha fraterculus (Wied.) adults in apple (Malus domestica) orchard but not in the peach (Prunus persicae) orchard. In apple, adults began to occupy the orchard in arcas adjacent to the forest, and concentrated its presence in the forest and surroundings. In peach, 90.5% of the flies were captured within the orchard, and only 0.5% in the forest or nearby. Within the apple orchard, 43.0% of the flies were captured, and the first flies invading the habitat were females, while in peach both sexes occurred simultaneously, especially females. It was possible to characterize a pattem of adult colonization and distribution in peach and apple agroecosystems. In peach, fruit presence (especially dose to ripening) had a positive correlation with adult occurrence and distribution, while in apple this did not occur.

Important contribution for oat genetic improvement is the possibility to use mechanisms that increase geneticvariability. The objective of this work was to evaluate and compare the sensibility of hexaploid oat fixed genotypes as aresponse to the employment of mutagenic agents. Two mutagenic chemicals, ethyl methanesulphonate (EMS) and methylmethanesulphonate (MMS), and one physical (gamma rays), in three doses, were tested in four genotypes. The experimentaldesign was a randomized complete block with three replicates for each treatment, where the experimental unit was composedby a gerbox with germitest paper and 100 seeds. Averages were compared by the Scheffé test. Data indicate linear decrease ofthe characters germination and root length with the increase of the mutagenic dose. Only the linear effect of mutagenic EMSwas significant. Within the studied interval (0-3%), germination decreased (b= -1,03) with the increase of the EMS doses.Gamma radiation caused significant reduction in root length (b = -4,72), as compared to the other mutagenic agents.