Companies have sought to improve, more and more, the quality control of the seeds produced, improving tests that evaluate the vigor of the seeds with greater speed and precision. The objective of the present work was to study the effects of imbibition time on the results of the electrical conductivity test to evaluate the vigor of millet seeds and to correlate with the other tests carried out. Six seeds lots of the ADR300 cultivar with different vigor levels were used. Germination, first germination count, accelerated ageing, emergence and emergence speed of seedlings in sand and electrical conductivity with variations in water volume were performed (50 And 75 cm 3 ), during the imbibition time of 2, 4, 6 and 8 hours, at 25 ºC. The time of 2 hours of the seed imbibition in 75 cm 3 in water proved to be efficient to evaluate the vigor of millet seeds in all lots tested.

No abstract

Stored beans have active metabolism and respiration may cause significant quality losses. Therefore, some care is necessary during this period, aiming at maintaining the physiological quality of seeds, minimizing their deterioration and reducing their germinative power. Seed quality during storage may be influenced by environmental factors and the interaction of genotypes with the environment. The objective was to evaluate the germination and vigor of bean seeds after 90-days storage under different temperature conditions. The experiment was conducted under a completely randomized design, with four replications, in 3 × 2 factorial scheme, considering three storage temperatures (10 °C, 20 °C and 30 °C) and two storage times (0 and 90 days). For potential evaluation, the following characteristics were considered: moisture content, thousand seed mass, germination, electrical conductivity, accelerated aging and cold test. Numerical data were submitted variance analysis with averages compared by means test at 5% of significance. Results showed that storage temperature conditions directly affect physiological quality of bean seeds. Temperature of 10 °C provided better seed conservation whereas temperature of 30 °C promoted higher deterioration and reduced vigor.

The objective of this research was to quantify the photosynthetic efficiency of Cedrela fissilis and Schinus terebinthifolius seedlings after application of salicylic acid for eight weeks. The experimental design was completely randomized, composed of four treatments, with five replicates of 20 seedlings each. The treatments consisted of increasing doses of the salicylic acid solution: 0, 100, 200, 300 mg L-1. The solution was composed of salicylic acid, deionized water and adjuvant and applied with hand sprayer, weekly for 2 months. The parameters evaluated after the application of the acid consisted of the rate of CO2 assimilation, leaf transpiration, stomatal conductance and internal CO2 concentration, as well as water use efficiency, intrinsic water use efficiency and instantaneous carboxylation efficiency. In seedlings of Schinus terebinthifolius there was a reduction of the photosynthetic parameters and consequently a better use of water as the doses of the plant growth regulator were increased. In the seedlings of Cedrela fissilis the dose of 200 mg L-1 resulted in greater CO2 fixation per molecule of water lost and in this sense, it can be inferred that the increase in the doses of salicylic acid improved the photosynthetic efficiency, but the use of water was lower. Thus, for both species, lower doses are more recommended because there must be a balance between the fixed amount of CO2, the plant generated from photoassimilates and the amount of water lost, in order not to generate a negative potential in the plant metabolism.