Testes de vigor para avaliação da qualidade fisiológica de sementesde Sebastiania commersoniana (Baill.) Smith & Downs.

The objective of this work was to evaluate the efficiency of different vigor tests to assess S. commersoniana seeds physiological quality during storage. Therefore, seeds were stored in cloth bags, plastic bags and glass containers for 531 days, both at room temperature and in a cold chamber. Periodically samples were taken and the following tests were conducted: standard germination, germination speed index, first count after germination, seedlings fresh and dry matter, electrical conductivity (imbibitions for 2 and 24 hours) and accelerated aging, in order to monitoring the seeds physiologic quality. Data were submitted to polynomial regression analysis, for each of the combination of packaging/storage condition. The results obtained led to the following considerations: a) the speed germination index and the accelerated aging test permitted a good evaluation of the seed-lots quality; b) the first count of germination did not allow any prediction about seed lots vigor; c) seedling fresh and dry matter did not discriminate among seed lots; d) electrical conductivity test after 2 h imbibitions was not adequate to evaluate the seed lots vigor and e) the electric conductivity test with 24 h imbibitions was more adequate to differentiate among seed lots, but with little efficiency to discriminate among seed lots with intermediate vigor or with low quality differences.

Avaliação do vigor de sementes de rúcula pelo teste de lixiviação de potássio

The objective of this study was to evaluate methodologies for the potassium leaching test and to verify its sensitivity for identifying different levels of vigor of arugula seed lots. Five seed lots each of Rucula Cultivada and Rucula Gigante were used. Standard germination, first count of germination, seedling emergence and variations of the potassium leaching test (50 or 100 seeds imbibed in 50 mL or 75 mL in water; at 25 °C and 30 °C; for 0.5 h, 1 h, 1.5 h, 2 h, 2.5 h, 3, 4 and 5 hours) were done. It was observed that the period seeds need to be soaked can be reduced to 2 hours and the water volume can be reduced to 50 mL. The utilization of 50 seeds showed a smaller variation coefficient and the best temperature was 30 °C. It can be concluded that the potassium leaching test for arugula seeds can be run using 50 seeds in 50 mL of water for 2 hours at 30 °C.

Qualidade de sementes de crambe submetidas a métodos de secagem e períodos de armazenamento

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Doses de fósforo no acúmulo de nutrientes, na produção e na qualidade de sementes de couve-flor

Pós-graduação em Agronomia (Horticultura) - FCA

Testes laboratoriais para a avaliação do desempenho germinativo no campo de sementes de lotes de soja (Glycine max (L.) Merrill

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Testes de vigor em sementes de milho

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Etapas do beneficiamento na qualidade física e fisiológica de sementes de milho

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Desempenho de sementes de couve-flor em função de níveis de vigor e resposta à aplicação de nitrogênio

Pós-graduação em Agronomia - FEIS

Produção e qualidade de sementes de soja convencional e geneticamente modificada em relação à aplicação via sementes e foliar de produto bioestimulante

Pós-graduação em Agronomia - FEIS

Teste de envelhecimento acelerado em sementes de milho-doce (sh2)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Testes de vigor em sementes de quiabeiro

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Disponibilidade hídrica na germinação de sementes e no crescimento de plântulas da leguminosa forrageira Macrotyloma axillare (E. Mey) Verdc. cv. Java

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeito imediato do método de secagem na qualidade de sementes de crambe

Crambe (Crambe abyssinica Hochst) seeds have high oil contents and its growth in Brazil aims to produce bio diesel. The crambe seeds production and commercialization began a few years ago. Research in technology production is essential and it is also important to use high quality seeds regardless of the technological level employed in the crop production. One of the factors that affect seed quality there is the drying process. Seed drying performed properly can reduce seed moisture content for storage without decrease in its qualitative characteristics. The aim of this study was to evaluate the immediate effect of natural and artificial drying methods (using heated and unheated air) on crambe seeds quality. The seeds were produced at Fazenda Lageado, Faculdade de Ciências Agronômicas, UNESP, Botucatu/SP, on April 2009. Seeds were submitted to the following drying methods: a) seed drying in the shade with natural ventilation; b) artificial drying method using heated air; c) artificial drying method using unheated air; d) drying on ceramic patio; e) drying on the mother plant. The seeds were evaluated immediately after drying. The following tests were performed: seed moisture content; standard germination; first count of germination; seedling emergence; emergence speed index and electrical conductivity. The experimental design was randomized blocks and the data obtained was subjected to analysis of variance, worth means being compared by Tukey test at 5% probability. There was no significant difference among drying treatments in relation to: germination rate, first count of germination, electrical conductivity, seedling emergence and emergence speed index. The highest percentage of abnormal seedlings was obtained on treatment with heated air drying. The drying on the mother plant method showed the lower percentage of dead seeds. The drying methods studied did not cause an immediate effect on crambe seeds quality, which showed high percentage of dormant seeds post-harvest.

Mathematical analysis of maximum power generated by photovoltaic systems and fitting curves for standard test conditions

The rural electrification is characterized by geographical dispersion of the population, low consumption, high investment by consumers and high cost. Moreover, solar radiation constitutes an inexhaustible source of energy and in its conversion into electricity photovoltaic panels are used. In this study, equations were adjusted to field conditions presented by the manufacturer for current and power of small photovoltaic systems. The mathematical analysis was performed on the photovoltaic rural system I- 100 from ISOFOTON, with power 300 Wp, located at the Experimental Farm Lageado of FCA/UNESP. For the development of such equations, the circuitry of photovoltaic cells has been studied to apply iterative numerical methods for the determination of electrical parameters and possible errors in the appropriate equations in the literature to reality. Therefore, a simulation of a photovoltaic panel was proposed through mathematical equations that were adjusted according to the data of local radiation. The results have presented equations that provide real answers to the user and may assist in the design of these systems, once calculated that the maximum power limit ensures a supply of energy generated. This real sizing helps establishing the possible applications of solar energy to the rural producer and informing the real possibilities of generating electricity from the sun.

Cytogenetic analysis of the neotropical spider Nephilengys cruentata (Araneomorphae, tetragnathidae): standard staining, NORs, C-bands and base-specific fluorochromes

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)