José Maria Gomes Neves

Qualidade de sementes de Helianthus annuus L. em função da adubação fosfatada e da localização na inflorescência

In recent years, the expansion of sunflower promoted a search for genetic material more competitive, and for seeds with a maximum physical, physiological and health quality. In the field, harvesting time and plant nutrition are essential in the expression of these qualities. With this objective, this research aimed to evaluate the physical and physiological quality of sunflower seeds under different phosphorus levels and locations within the same inflorescence. The experimental design was randomized blocks in factorial (3x2), being the first factor, the location of the seed in the inflorescence (outside, middle and center) and the second phosphorus levels (zero and to 70kg ha-1 super-simple). Its application was performed during the culture deployment . Seeds were subjected to the moisture content determination, thousand seed weight, seed weight per inflorescence location in germination and vigor (first count and index of germination rate). Phosphorus fertilization allowed an increase in physical and physiological quality of sunflower seeds. The region along the periphery with the environment contributes in most to obtain a better physical and physiological quality of sunflower seeds. The physical quality is affected by the location of seeds in inflorescences, which are heavier in the periphery, followed by middle and having the center with lighter seeds.

Physiological quality of osmoprimed gherkin seeds

It was aimed to verify the effect of different methodologies of osmopriming on physiological quality of gherkin seeds. Prior, it has been characterized the initial profile of the gherkin seeds. Then, the seeds were osmoprimed in gerboxes containing two blotter papers wetted with osmotic solutions in a volume equal to three times the paper dry weight and kept in BOD at 15 °C. After the priming, the seeds were dried at room temperature for 48 hours. Then, the following variables were evaluated: seeds moisture content, percentage of germination, percentage of emergence, emergence speed index and electrical conductivity. The analyses of variances were realized according to a randomized design in a factorial scheme 3 x 2 x 4: three solutes (polyetilene glycol 6000 - PEG, potassium nitrate - KNO3 and PEG + KNO3), two osmotic potentials (-0.55 and -1.10 MPa) and four times of priming (24, 48, 72 and 96 hours), followed by analyses of regression. It is concluded that the priming has no effect on germination and affects positively the vigor of the gherkin seeds lots; osmopriming with potassium nitrate is effective in improving the physiological quality of gherkin seeds lot.

DETERMINAÇÃO DE INIBIDORES E SUPERAÇÃO DE DORMÊNCIA EM SEMENTES DE CUTIEIRA

The objective of this work was to verify the presence of inhibitors of germination and vigor in different parts of the seed of Cutieira. Secondly, we evaluate the effects of the methods for breaking dormancy, as well as to identify and quantify the microflora in Cutieira seeds. In the preliminary phase of the research, using lettuce seeds as an indicator of inhibitors and aqueous extract of seed coat, film, tissue reserves, cotyledon and embryo axis of Cutieira seeds. It was evidenced the presence of inhibitors primarily in tissues of the embryonic axis and cotyledons. In a second stage of the research, in finding overcomes Cutieira seed dormancy, fruits of Cutieira were collected and separated into freshly harvested fruits and remnants. The experimental design was completely randomized, factorial 2 x 5, with two types of seed from freshly harvested fruits and remnants and five pre-germination treatments. The seed coat removal promotes increased germination and seed vigor derived from harvested fruits. Fungi identified in the cutieira seeds were Aspergillus niger, Aspergillus flavus, Penicillium sp. and Rhizopus sp.

Curva de absorção de água em sementes de Pinhão-Manso (Jatrophas curcas L.)

RESUMO – O presente trabalho teve o objetivo de caracterizar a curva de absorcao de agua em sementes de pinhao-manso (Jatrophas curcas L.) pelo metodo teste-padrao, com sementes mantidas em rolo de papel de filtro umedecido em agua destilada. O delineamento experimental foi o inteiramente casualizado, em esquema fatorial 2 x 16, sendo 2 classes de sementes (vivas e mortas), com 16 periodos de embebicao e 4 repeticao de 10 sementes por parcela. E foi realizado o teste de tetrazolio para verificar a nao viabilidade das sementes. As sementes de pinhao-manso apresentaram o padrao trifasico de embebicao. Onde a fase I foi comum para as sementes vivas e mortas, estendendo-se por 15 horas. Apenas sementes vivas ingressaram na fase II, estendendo-se por 45 horas, sendo compreendida entre 15 ate 60 horas de embebicao. Somente sementes vivas ingressaram na fase III, apos 60 horas de embebicao, quando foi possivel visualizar a emissao da radicula. CURVE OF WATER ABSORPTION IN SEEDS JATROPHA (Jatropha curcas L.)