Suemar Alexandre Gonçalves Avelar

QUALIDADE DE SEMENTES DE SOJA ARMAZENADAS APÓS RECOBRIMENTO COM AMINOÁCIDO, POLÍMERO, FUNGICIDA E INSETICIDA 1

The objective of this study was to evaluate the effect of soybean seed coating treatment with amino acid, polymer, fungicide and insecticide on physiological and health quality. The treatments were: 1) control; 2) fungicide (Fludioxonil + Metalaxil); 3) amino acid (PT-4-0®); 4) polymer (Polyseed CF®+ Colorseed®); 5) fungicide + amino acid; 6) fungicide + insecticide (Thiametoxam); 7) fungicide + polymer; 8) fungicide + insecticide + polymer; and 9) fungicide + amino acid + insecticide. Germination, vigor and seed health were evaluated. The seeds were stored for six months and evaluations done every 60 days. The application of amino acid alone positively affected seed germination but when combined with fungicide and polymer there was no improvement in seed performance. Germination was negatively affected by using fungicides but the combination of fungicide and polymer had no effect. Fungicide application reduced fungus incidence, except for Cercospora sp. The use of polymer did not affect fungus control by the fungicide, indicating that this combination can be used.

Critical levels of organic acids on seed germination and seedling growth of wheat

The objective of this study was to determine the responses of the wheat cultivars CD 108 and CD 111 for tolerance to organic acids. The effects of five concentrations of the three main acids formed in the soil were studied: acetic acid (0, 4, 8, 12 and 16 mM), propionic acid (0, 4, 8, 12 and 16 mM) and butyric acid (0, 2, 4, 8 and 12 mM). Tests included germination, shoot length, root length and dry weight of shoot and root. The variable root length is the most responsive variable for all the acids tested and the critical level of toxicity of acetic, propionic and butyric acids, which reduced root length by at least 50% was 9.0, 8.5 and 4.0 mM respectively. It was concluded that the presence of acetic, propionic and butyric acids in the germination substratum of wheat seeds of the cultivars CD 111 and CD 108 reduced seedling development, mainly by reducing the length of the radicles.

Secagem estacionária de sementes de soja com ar desumidificado por resfriamento

The objective of this study was to monitor the drying process of soybean seeds using cooled, dehumidified air. Soybeans seeds of the Campo Mourao cultivar were dried in a stationary dryer, Dry-Excel model, with a radial distribution of the air flow, a 10 ton capacity and a Dry 60® equipment. The drying process consisted of lowering air humidity by cooling below the dew point temperature and subsequently warming up to 33 °C until a 40% relative humidity had been reached. Drying was made by an air flow of 17 m3.min-1.t-1. During drying, seed samples were collected at radial distances of 0.15 m, between 0.15 and 0.45 m and 0.45 and 0.60 m from the central cylinder and at heights of 0.5, 2.4 and 4.3 m from the dryer base. The following evaluations were made: loss of water and temperature of the seed mass at one hour intervals for six hours, germination, first germination count, accelerated aging and speed index of field emergence. It was concluded that it is possible to dry soybean seeds on a commercial scale using air dehumidified by cooling and reduced temperatures. Since the bin dryer has a central perforated tube, drying is not uniform and the drying rates and final moisture contents obtained varied according to seed position in the dryer; seed physiological quality is maintained by drying with air dehumidified by cooling, independently of the seed position in the drier.

DESEMPENHO DE SEMENTES E PLANTAS DE MILHO HÍBRIDO ORIGINADAS DE LOTES DE SEMENTES COM ALTA E BAIXA QUALIDADE FISIOLÓGICA

Estrategias que busquem aumentar a produtividade de palha pelas culturas devem ser implementadas na regiao dos Cerrados, no sentido de consolidar o plantio direto. Objetivou-se avaliar a influencia das epocas de aplicacao e do parcelamento da fertilizacao nitrogenada suplementar a adubacao de semeadura no milho sobre a produtividade de palha de aveia preta, especies espontâneas e a influencia desse parcelamento nos diversos componentes da cultura. Os tratamentos constaram da aplicacao de 70kg/ha de nitrogenio, como dose suplementar a adubacao de semeadura do milho, em epocas distintas: na semeadura da aveia-preta; oito dias antes da semeadura do milho; em cobertura, quando as plantas tinham quatro a cinco folhas; em cobertura, quando as plantas tinham sete a oito folhas. Na semeadura, aplicaram-se 42kg/ha de N em todas as parcelas. A adubacao nitrogenada aplicada na semeadura da aveia nao resultou em aumento da produtividade de palha, na entressafra. Houve aumento da produtividade de palha pelo milho quando se aplicou o nitrogenio suplementar a semeadura, assim como a aplicacao mais proxima da semeadura proporcionou aumento da produtividade em relacao a aplicacao do fertilizante na semeadura da aveia.