The aim of this work was to correlate macronutrient content of soybean seeds to physiological quality of different cultivars. The work was developed in the Federal University of Pelotas, in the facilities of the Seed Science and Technology Graduate Program. The experimental design was randomized blocks in arranged in four replicates. The following soybean cultivars were used: BMX Apolo RR (12 lots), BMX Ativa RR (13 lots), BMX Energia RR (26 lots), BMX Força RR (24 lots), BMX Impacto RR (35 lots), BMX Magna RR (16 lots), BMX Turbo RR (44 lots), BMX Potência RR (82 lots) and NA 5909 RR (28 lots), with seeds produced in northwest Rio Grande do Sul. The determination of nutritional contents found in plant tissues of soybean seeds, were measured: Nitrogen (N), Phosphorus (P), Potassium (K), Magnesium (Mg), Calcium (Ca), Sulfur (S). The macronutrient contents of the seeds vary according to genetic characteristics of the cultivars, with higher oscillations of nitrogen, phosphorus, magnesium and sulfur contents present in soybean seeds. Potassium and calcium are defined as the most stable nutrients for the cultivars and seed lots analyzed. High concentrations of nitrogen, phosphorus and calcium are determinants for the physiological quality of soybean seeds.

The objective of this study was to evaluate soybean growth, conversion of solar energy and seed vigour of plants cultivated with different nitrogen doses. We carried out experiments using the cultivar BMX Potência RR belongs to the maturation group 6.7, presenting an indeterminate growth habit. The experimental design was completely randomised with four replications in a 4 x 8 factorial scheme (four nitrogen doses and eight collection periods). In the Vn stage of soybean development, we applied four different nitrogen fertilisation doses, i.e. 0, 25, 50 and 75 Kg N ha -1 in the form of urea (45% of N). We evaluated leaf area (A f ), leaf dry mass (W f ), stem (W c ), roots (W r ) and pods (W v ), dry matter production rate (C t ), relative growth rate (R w ), net assimilation (E a ), rate, leaf area ratio (S a ), solar energy conversion factor (ξ), leaf area ratio (F a ) and leaf mass (F w ), dry matter partition between plant structures, seedling emergence (E) and the emergence speed index (IVE) of the seedlings originated from the seeds produced. The experiment was conducted throughout the crop cycle. Nitrogen application positively impacted soybean growth; a nitrogen dose of 50 Kg ha -1 resulted in highest values of W t . However, plants subjected to 75 Kg N ha -1 reached higher R w and L values. Nitrogen fertilisation applied in the stage Vn facilitated plant growth, enhanced the conversion of solar energy and resulted in higher seed vigour. Keywords:Glycine max (L.); relative growth rate; net assimilation rate; emergence; emergence speed index. Abbreviations: A f _Leaf area, C t _Dry matter production rate, E a _Net assimilation rate, E_Emergence, F a _ Leaf area ratio, F w _And leaf mass, IVE_And the emergence speed index, L_Leaf area index, N_Nitrogen, R w _Relative growth rate, S a _Leaf area ratio, W c _Stem, W f _Leaf dry mass, W r _Roots, W v _And pods, ξ_Solar energy conversion factor.

This study aimed to evaluate the physiological performance of white clover seed lots of different tegument colours, besides to analyses the electrical conductivity test methodology with different seeds number, water volume and soaking periods. The experiment was developed at the Seed Didactic Laboratory in the Agronomy College “Eliseu Maciel” at the Federal University of Pelotas, in Pelotas-RS, Brazil. White clover seeds were manually separate, composing four lots of different coloured seeds: yellow, orange, brown and mixed. White clover seeds of yellow colour tend to present greater physiological potential through its germination and vigour. The electrical conductivity test was not efficient on identifying different vigour levels in white clover seed lots.

The objective of this work was to evaluate the effects on the physiological attributes of soybean seeds submitted to the seed treatment with addition of insecticide, polymers and micronutrients throughout the storage. The experimental design was completely randomized in a factorial scheme, with four seed treatments per two seasons of storage of the seeds. The analysis of variance revealed a significant interaction among seed treatments and storage times for both cultivars at 5% of probability, referring to the characteristics of shoot length (SL), primary root length (RL), shoot dry mass (SDM) and dry mass of the primary root (RDM) for the cultivar Fundacep 37 RR. Addition of seed treatments influences the physiological performance of seedlings originated from soybean seeds stored for 240 days. The shoot and primary root lenghts, and shoot dry mass express the isoenzyme esterase through the aerial part and primary root of the seedling, the malate dehydrogenase is expressed in the primary root while in the peroxidase it is evident in the shoot of the seedlings.

In Brazil, Asian rust is the main disease that affects the soybean crop, which is responsible for the great inventiveness of financial resources with fungicides to control this pathogen. The objective of this work was to evaluate the grain yield and economic viability of the different combinations of fungicides used in the soybean crop. The experiment was conducted in the 2014/2015 agricultural year in the experimental field located in the municipality of Campo Novo-RS, Brazil. The treatments used correspond to 15 combinations of fungicides, and these were applied at different times during the soybean cycle. The characters measured weremass of 1000 seeds, grain yield, gross income, fungicide cost, total cost, net income, income gain and profitability. The grain yield of soybeans was reduced by 35% due to the absence of fungicide applications. Combinations of fungicides that provide the highest yields and profitability for soybean are based on the use of different active principles such asstrobilurins and carboxamides.