Danton Camacho Garcia

A secagem de sementes

The drying operation of the seeds is fundamental in the production system because it reduces the tenor of water to allow its physiologic quality preservation during the storage and makes possible the anticipation of the crop avoiding losses of several CAUSE. In the choice of the drying method, the amount seeds factor is limited and, when we need to dry larger amounts the use of artificial drying is indispensable, whose operation costs are related, mainly, with volume, drying speed and temperature of the air. It becomes important that the operators are aware of the drying conditions that they get to provide to the seeds, aiming to maximize the possible benefits or, on the other hand, to minimize to the maximum the inevitable and irreversible losses that happen from the moment that the seeds reach its maximum quality, still in the field.

Correlação entre absorção de água e tempo de cozimento de cultivares de feijão

The purpose of this work was to evaluate the behavior of bean cultivars regarding water soaking test and cooking time as well as the possible correlation of these variables to identify bean lines with high cooking capacity. A factorial of two cultivars (TPS Nobre and Perola) and different times (2 to 18 hours of soaking) in a completely randomized design, with three replications, was conducted. Soaking capacity was increased over time up to 13h07min for TPS Nobre and 13h12min for Perola cultivar. Cooking time was reduced after 12h49min of soaking for both cultivars. There was a high and negative correlation between water soaking and cooking time.

Métodos para avaliação do potencial fisiológico de sementes de alface

RESUMO – A alface (Lactuca sativa L.) e uma hortalica que se multiplica por meio de sementes e seu potencial fisiologico pode ser avaliada atraves do teste de germinacao e testes de vigor. No entanto, apenas o teste de germinacao esta completamente padronizado para esta especie, enquanto os demais necessitam de ajustes em suas metodologias a fim de torna-los precisos para a avaliacao do potencial fisiologico de sementes de alface. Os objetivos do trabalho foram comparar e identificar testes para avaliar o potencial fisiologico das sementes de alface. Utilizaram-se sementes de alface cv. Regina e Vera e os testes de germinacao, primeira contagem, solucao osmotica, envelhecimento acelerado, emergencia de plântulas, condutividade eletrica, comprimento de plântulas e massa seca de plântulas. O delineamento experimental usado foi o inteiramente casualizado, com os dados analisados atraves do teste de Tukey a 5% de probabilidade. O teste de germinacao mostrou diferencas entre lotes da cv. Regina e os testes de vigor estratificaram lotes quanto ao potencial fisiologico. Para a cv. Vera, os testes de vigor aplicados as sementes nao mostraram diferenca significativa entre os lotes, com excecao do teste de envelhecimento acelerado. Concluiu-se que o potencial fisiologico de sementes de alface pode ser avaliado com o uso dos testes de primeira contagem, envelhecimento acelerado e emergencia em gerbox, enquanto os testes de solucao osmotica e de condutividade eletrica necessitam estudos adicionais para adequar suas metodologias e viabilizar a sua utilizacao para sementes de alface.

Efeito da luz, temperatura e estresse hídrico no potencial fisiológico de sementes de funcho

The objective of this study was to evaluate the effects of light, temperature and hydric stress on the germination and vitality of fennel seeds.. First, the seeds were sowed on paper at constant temperatures of 20, 25, 30oC or alternating temperatures of 20-30oC in the presence or absence of light. In a second step, seeds were kept on paper in aqueous polyethylene glicol (PEG 6000) at the osmotic potentials equivalent to zero; -0,05; -0,10; -0,15; -0,20; -0,25;-0,30MPa. According to the results, it was possible to conclude that germination of fennel seeds occurred in presence or absence light. The fennel seeds germinated better at constant temperatures of 20 and 25oC but 30oC was not useful for the germination test. The decrease in the osmotic potentials reduced the germination and vigor of fennel seeds, and vigor was more affected than germination. The germination was drastically reduced, starting at -0,1 MPa for fennel when there was a decrease in the osmotic potentials with polyethylene glicol 6000.

Teste de condutividade elétrica em sementes de aveia preta

Determining physiological potential in black oats seeds shows some difficulties due to the lack of standardized tests. On the other hand, the measuring the electric conductibility of the seed immersion solution can be a fast method, that can be applied to oats seeds, because it indicates the integrity of cellular membranes, and gives us, indirectly, the information about the physiological quality of the seeds. The objective of this study was to evaluate the effect of the number of seeds and the imbibition time over the electrical conductivy of the solution, in the evaluation of the strength of oats seeds with and without shell. The experiment was conducted using three lots of common oats seeds. The test was made at 25o C, imbibition testing times of 4, 8 and 16 hours, with 25 and 50 seeds. The treatments constituted a factorial, using a complete randomized design with four repetitions. The use of 25 black oat seeds without shell in 75mL distilled water, with an imbibition time of eight hours, was enough to stratify the lots in different strength levels.

COMPARAÇÃO ENTRE MÉTODOS PARA AVALIAÇÃO DA QUALIDADE FISIOLÓGICA E SANITÁRIA DE SEMENTES DE MELÃO 1

RESUMO - O objetivo do trabalho foi avaliar a eficiencia de diferentes testes na identificacao do vigor e da qualidade sanitaria de lotes de sementes de melao (Cucumis melo L.). Foram avaliados quatro lotes de sementes das cultivares Gaucho e Carvalho, produzidas no municipio de HulhaNegra-RS submetidas aos testes de germinacao, primeira contagem de germinacao, emergencia em campo, deterioracao controlada, envelhecimento acelerado, classificacao do vigor de plântulas e sanidade. Os resultados indicaram que os testes de deterioracao controlada e envelhecimento acelerado apresentam sensibilidade suficiente para avaliacao do potencial fisiologico de sementes de melao, mas os testes de avaliacao de plântulas nao mostraram sensibilidade suficiente para realizar uma estratificacao dos lotes pelo vigor. Patogenos como Aspergillus spp. e Fusarium oxysporum interferem na qualidade fisiologica das sementes de melao.

PRÉ-GERMINAÇÃO DE SEMENTES DE ARROZ DE SEQUEIRO 1

Pre-germination is a technique of seed physiological conditioning of seeds that is based on their controlled hydration, preparing them for germination and the initial development of the seedlings. The objective of this study was to evaluate the effects of the physiological conditioning, through the pre-germination at the temperatures of 20 and 25°C, with subsequent drying of the rice seeds cv. Primavera. The seeds were submitted to immersion in water for periods of 8, 16, 24 and 32h, followed by 16, 24, 32 and 40h incubation. At the two temperatures, after conditioning, the germination tests and first count tests were applied. For the temperature of 25°C, in addition, initially, the imbibition curve was determined and, later, the cold test and the length and dried seedling mass tests were applied. At the temperature of 25°C, the treatment of 8 h of immersion and 16h of incubation presented humidity of 30.5%, considered enough for metabolic activation and presenting the best results detected in the vigor tests. It was concluded that the periods of 8 h immersion for16 h of incubation, at the temperature of 25°C and, 16 h of immersion for 24h of incubation, at the temperature of 20°C, are suitable for the pre-germination of upland rice seeds cv. Primavera. The drying of the seeds, after the pre-germination, can be accomplished up to 17.0%, without damage to the physiological quality, however, the reduction of the water content to 13.0% annuls the benefits of the treatment, harming the seed vigor.

Qualidade de sementes de milho armazenadas em diferentes embalagens

The storage is a decisive part of seed production of high quality. The objective of this study was to evaluate the physical, physiological and sanitary quality of three maize varieties seeds, stored for six months in plastic packaging and cotton bags. Germination, quantification of insect damage and seed health were evaluated. In the plastic packaging storage, were observed reduction in the germination, but the presence of insect pests was lower. The storage in cotton bag reduced the seeds quality, due to the presence of insect pests and the high incidence of Fusarium, Penicillium and Aspergillus. The storage in plastic package provided the maintenance of seeds quality, with a lower incidence of insects and fungi when compared to the cotton bags. The varieties showed different answers in relation to the packages used.

Heterogeneity index of zucchini yield on a protected environment and experimental planning

The objectives of this work were to assess zucchini heterogeneity index and fruit weight at different harvest frequencies for plants grown on a protected environment; to estimate the optimum plot size; and to determine the least significant difference among treatments, varying plot size and replication number. Plants of cultivar Caserta were grown in a plastic greenhouse, using spaces of 0.80 x 1.00 among plants and lines, respectively. The following harvest frequencies were studied: fruits harvested daily, (1) at 10:00, (2) at 10:00 and 18:00, (3) at 8:00, 10:00, 12:00, 14:00, 16:00 and 18:00 h and; (4) fruits harvested every other day, at 18:00 h. Twenty-seven harvests were carried out, collecting fruits larger than 0.15 m. Plots were planned with 1, 2, 3, and 6 plants per row. Heterogeneity index was estimated according to Smiths method and, the optimum plot size, according to modified maximum curvature method. Fruit yield per plant gradually increased reaching a maximum at the 15th harvest. Total yield was of 3214, 3124, 3928 and 3248 g plant1, respectively, at the harvest frequencies 1, 2, 3 and 4, with no significant differences among them. The heterogeneity index in the plastic greenhouse was nearly zero. The use of smaller plots combined with a larger number of replications increased the experimental accuracy. Although optimum plot size to assess total fruit yield varied between one and seven plants, depending on the harvest frequency, plots with three plants per row plots, with six replications, were the most appropriate design, allowing detecting a least significant difference among treatments equal to 76% of the mean.

Teor de proteína e qualidade fisiológica de sementes de arroz

O trabalho teve como objetivo avaliar o teor de proteina como elemento auxiliar na determinacao da qualidade fisiologica de sementes de arroz, alem de correlaciona-la com a emergencia em campo. Foram utilizados seis lotes de sementes de arroz, sendo tres lotes da cultivar IRGA 417 e tres lotes da cultivar IRGA 422 CL, submetidas ao conjunto de testes, para caracterizar o potencial fisiologico dos lotes: germinacao, primeira contagem de germinacao, envelhecimento acelerado, frio sem terra, comprimento de plântula e massa seca de plântula. Apos a determinacao da qualidade inicial dos lotes foi aplicado novo conjunto de testes, composto pelo teor de proteina bruta e pelas avaliacoes das plântulas e plantas em campo. Conclui-se que o teor de proteina bruta e capaz de identificar diferencas entre lotes de arroz, em funcao da qualidade das sementes, e correlacionar-se com a emergencia em campo, quando ocorre em condicoes desfavoraveis; portanto, trata-se de uma determinacao promissora para associacao aos testes convencionais a fim de avaliar o potencial fisiologico das sementes de arroz.