The differentiation of seedling growth and development is the result of the vigor level of the seed lot. Because of this, knowing the seedling growth curve is essential for the evaluation of the seedling length test, to be carried out at the moment when any differences in vigor really manifest, thus being able to reduce the time of evaluation of the test. In this research, the objective was to determine the most efficient time interval to perform the seedling length test in soybean seeds, depending on the vigor levels. The evaluated characteristics were percentage of seed germination, first germination count, emergency, days for emergence, aerial, root and total length (evaluated every 12 hours), aerial, root and total dry mass in completely randomized design. High vigor seeds originated seedlings with higher growth rates (cm. h-1), with vigor being one of the factors that interfere in the seedling length test. After 96 hours of the seedling length test, there was a statistical differentiation between the three vigor levels tested. The soybean seedling length test between lots, with different vigor, can be performed 96 hours after sowing.

Soybean is one of the leading commodities in Brazilian agribusiness. Its cultivation is widespread in different seed-producing regions of the country, where it generates income and local development. In this context, the soybean seed is a fundamental input, as its quality strongly influences the success of the crop. However, the period after the achievement of physiological maturity is critical for the maintenance of seed quality. For that reason, this study aimed at evaluating the effect of harvest delay on both the initial and final qualities of soybean seeds. The research consisted of four harvest times, in which the initial quality was assessed through tests of first germination count, germination, accelerated aging and tetrazolium. After 120 days of storage, the germination and accelerated aging tests were once again conducted. The experiment complied with a completely randomized block design with eight replications. The rainfall was monitored during the pre-harvest phase. All variables experienced negative impacts due to the delay in harvesting. Also, the seeds suffered more damage as the delay progressed, and the variables germination and seed vigor decreased after the storage period.

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The objective of this study was to determine adequate conditions of water volume, seed quantity and immersion period to perform the electrical conductivity test, and to analyze the parameters of the accelerated aging test and its correlation with the the physiological potential of amaranth seeds. Five lots of amaranth seeds (Amaranthus cruentus), cultivar BRS Alegria, were used. The initial evaluation of the quality of these lots comprehended the following tests: water content, germination, first germination count, accelerated aging (traditional method, and modified versions, using unsaturated and saturated saline solution for the periods of 24, 48 and 72 h), electrical conductivity in different periods (2, 4, 6, 8 and 24 h), different quantities of water (25, 50 and 75 mL), different seed quantities (100 and 150), and field emergence. It could be concluded that the accelerated aging test at 41 °C, for 72 h, using unsaturated NaCl solution was efficient in the classification of amaranth seed lots in levels of vigor. The electrical conductivity test performed for 8 hours with 25 mL of water and 100 seeds was efficient in the classification of amaranth seeds as to their physiological potential.

Storage is a fundamental step for maintaining seed quality after processing. Thus, in this study, we evaluated the physiological potential of onion seeds stored in different packings and environments. Impermeable, semi-permeable and permeable packings were tested under natural environment conditions (+19ºC), cold and dry chamber (10±2ºC and 33% RH) and cold chamber (16±2ºC and 60% RH), at 0, 90, 180, 270 and 360 days. The design was completely randomized in a 3x3x5 factorial scheme, with three replicates. In order to evaluate emergency in field, a 3x3 factorial arrangement (packing x environment) was adopted. Onion seeds maintained their physiological quality when stored in impermeable packing for 360 days, regardless of the environment. The seeds' physiological quality was maintained in the other packings when stored in a cold or cold and dry chamber, with viability and vigor above 80% up to 180 days of storage.