Nutrição do feijoeiro e intensidade da antracnose em função da aplicação de silício e cobre

The objective of this work was to evaluate the effect of calcium silicate and copper sulfate on anthracnose intensity and nutrition of bean plants. The experiment was conducted using an experimental design in randomized blocks following a 4 x 4 factorial arrangement, (four levels of calcium silicate and four levels of copper sulfate) and two additional treatments (plants without inoculation and plants sprinkled with Benomyl). Four evaluations of the incidence and severity of anthracnose were done, in addition to measuring total leaf area. At the end of the evaluations, incidence and severity data were integrated over time, obtaining the area under disease progress curve (AUDPC). Contents of N, P, K, Ca, Mg, B, Cu, Fe, Mn, Zn, Si and lignin were determined in the aerial part. A linear decrease of the intensity AUDPC was observed with the increase of the doses of calcium silicate. The severity AUDPC was influenced by the doses of copper, obtaining a reduction of 35% on the higher dosage. The supply of silicon and copper altered the content of the K, Mg, S, Zn, Ca and Si in the aerial part of the bean plants.

Síntese e aplicação de catalisadores à base de óxidos de cério, tungstênio e HZSM-5 para a produção do biodiesel

This work presents a study on the production of biodiesel by esterification reaction of oleic acid with methanol using batch reactor and different catalysts based on CeO2 and WO3 and HZSM-5. Acid treatment was performed in order to increase the catalytic activity. Different characterization techniques were performed, among them X-ray diffraction (XRD), Thermogravimetric analysis TGA/DTA, Spectroscopy in the Region in Fourier Transform Infrared (FTIR) and X-ray fluorescence (XRF). The effects of independent variables: temperature, molar ratio of oil: alcohol and the amount of catalyst and their interactions on the dependent variable (conversion of oleic acid to the corresponding ester). Overall, through the results obtained in the characterization was observed that the applied treatments were efficient, however the XRF technique, indicated that tungsten oxide leaching could occur during the preparation of the materials. The treatments performed on HZSM-5 caused no significant changes in the structure indicating that the zeolite was quite resistant to the treatments used. It was evaluated using complete 23 factorial design. For the catalysts investigated, the best reaction conditions were obtained when using higher levels of the independent variables temperature and amount of catalyst. However, for the variable molar ratio the lowest level showed significant yields for most of the synthesized catalyst, obtaining maximum conversion to the OC (67.97%), OW (74.37%), HZSM-5 (61.16%) OC-OW 1 (75.93%), OC-OW 2 (82.57%), OC-OW 3 (79.15%), S/OC-OW 1 (86.90%), S/OC-OW 2 (91.04%), S/OC-OW 3 (88.60%), S/OC-OW/H 1 (92.34%), S/OC-OW/H 2 (100%) and S/OC-OW/H 3 (98.16%). According to the experimental design, the temperature has the biggest influence on the reaction variable for all the synthesized catalysts. Among the catalysts investigated S/OC-OW/H 2 e S/OC-OW/H 3 were more effective. Reuse tests showed that the catalyst activity decreased after each cycle, indicating that the regeneration process was effective. The leaching test indicated that the catalysts are heterogeneous in the evaluated operating range. The catalysts investigated showed themselves promising for the production of biodiesel.

Aspectos nutricionais do baru (Dipteryx alata Vog.) em casa de vegetação e em campo

With the objective of evaluating the response of baru (Dipteryx alata Vog.) to nutrient limitation and to the different levels of fertilization, seven experiments were conducted. Experiment 1: Nutritional limitation in greenhouse. We employed 12 treatments in a completely randomized design with eight replicates. Experiment 2: Levels of liming and P in greenhouse. The experimental design was completely randomized in a factorial scheme with four levels of liming (V23.2% (natural soil), V45%, V65% and V85%) and four doses of P (0, 100, 300 and 500 mg kg -1 of P). Experiment 3: Doses of N in greenhouse. We used seven treatments (0, 75, 150, 225, 300, 375 and 450 mg kg -1 of N) in a completely randomized design. Experiment 4: Doses of K in greenhouse. We used seven treatments (0, 75, 150, 225, 300, 375 and 450 mg kg -1 ) in a completely randomized design. Experiment 5: Levels of liming under field conditions. We used four treatments (V6.7% (natural soil), V35%, V55% and V75%) in a randomized blocks design. Experiment 6: doses of P under field conditions. We used five treatments (0, 23.67, 53.34, 106.67 and 213.36 kg ha -1 of P 2O5) in a randomized blocks design. Experiment 7: Doses of N under field conditions. We used five treatments (0, 30, 60, 120 and 240 kg ha -1 of N) in Latin square. In greenhouse, the evaluations were conducted at eight months (for experiments 1 and 2) and 12 months (for experiments 3 and 4) after seeding, when the measurements of height and root collar diameter of the seedlings. Subsequently, the plants were harvested and separated into shoot and root system, for weighing and evaluating dry biomass gain. In the field, the evaluations were conducted at six, 12, 18, 24 and 30 months (for experiments 5 and 6) and at six, 12 and 18 months (for experiment 7). In these experiments, we evaluated the survival of the seedlings, height of the plants and diameter of the stem at soil height. The data obtained were submitted to analysis of variance, mean tests and regression analysis. In conclusion, during the phase of seedling formation, the species is little demanding in S and B, negatively responds to liming, positively responds to phosphate fertilization and does not respond to nitrogen and potassium fertilization. In the field, in general, the species does not respond to the application of P or to liming, and is negatively influenced by the application of elevated doses of nitrogen.