Carlos Machado dos Santos

Qualidade das sementes de soja após a colheita com dois tipos de colhedora e dois períodos de armazenamento

Soybean mechanical harvest may bring qualitative losses to seeds. This study aimed to evaluate the quality of soybean seeds mechanically harvested by axial and conventional threshing systems, at different displacement speeds of the harvesters, before and after the storage period of six months. A randomized complete block design in a split-plot arrangement with four replications was used. The main plots were the harvest systems and the split-plots were the storage times. The harvest systems were: axial flow harvester, at 6, 8 and 10km h-1, conventional harvester, at 4 and 6km h-1, and manual harvest. Germination, percentage of normal seedlings, emergency speed index, sand emergency and mechanical damage of soybean seeds were evaluated. The results showed that the use of axial flow and conventional harvesters did not affect the emergency speed index, vigor and germination of soybean seeds. However, the axial flow system provided less mechanical damage. The increase of displacement speed, within the ranges of the operating parameters recommended by the manufacturer, did not change seed quality. Storage reduced seed vigor.

Biometria de frutos e sementes e emergência de plântulas de duas espécies frutíferas do gênero Campomanesia

The species Campomanesia adamantium and Campomanesiapubescens are morphologically similar, occur in common areas in the Cerrado, so they are difficult to be separated and identified. The objectives were to analyze biometrics of fruits and seeds of C. adamantium and C. pubescens, and the process of emergence of seedlings, for comparisons between species. In November 2007, 50 fruits of each species were measured of the transversal length (mm) and longitudinal (mm) of the fruits and seeds, fresh weight of fruits (g), number of locules per fruit and number of loci seeds. For the emergence testing, two independent experiments, one for each species, were installed in a completely randomized design with six methods of fruit processing for removal, drying or washing the mucilage, and four replicates with 40 seeds per plot. With the fruits of greater volume, with accumulation of fresh and wider biometrics in relation to C. pubescens, C. adamantium has a potential for selection of promising materials for breeding purposes. Drying in the shade for 24 hours with seed mucilage reduces the percentage of emergence and normal seedlings of C. adamantium, besides the seedlings emergence rate, although this method is indifferent to seedlings of C. pubescens. Under the same experimental conditions, seedlings of C. pubescens have a higher capacity emergence and normal seedlings as well as higher daily frequencies of seedlings emerged and reducing the time of emergence in relation to the seedlings of C. adamantium.

Composição química e qualidade fisiológica de sementes de girassol de plantas submetidas à competição intraespecífica

The objective of this study was to evaluate the chemical composition and physiological quality of sunflower seeds from different regions of the flowering head and from plants originating from high and low vigor seeds subjected to intra-specific competition. The experimental design was randomized blocks with four repetitions with treatments distributed in split plots. In the plots, five proportions of high vigor seeds sown in furrows were evaluated, whereas in the sub-plots, evaluations were made of the plants originating from high or low vigor seeds and two additional treatments. The relationship between the proportions of high vigor seeds and their position in the flowering heads was evaluated. The percentage of proteins, lipids, total carbohydrates, ashes, moisture content, weight of a thousand seeds and emergence parameters (beginning, middle and final times, mean emergence velocity, uncertainty, synchronicity, coefficients of variation of time and emergence), obtained from the emergence test in sand, were determined. The results indicated that: the proportion of seed vigor in the furrow interferes in plant performance and the resulting seed quality; the chemical composition of the seeds depended on seed position in the flowering head; the position of the seed in the head affected the germination variables.