ABSTRACT:In a quality control program, seed vigor evaluation is of fundamental importance for the success of the program. The objective of this project was to evaluate the efficiency of several vigor tests to evaluate the physiological quality of Brachiaria brizantha cv. 'BRS Piatã' seed lots and to preview seedling emergence in the field. Ten grass seed lots of the B. brizantha cv. 'BRS Piatã' were evaluated by the following tests: germination, first count of germination, accelerated aging (43 °C/48 hours), cold test (seeds rolled in paper towel), seed water content before and after accelerated aging, electrical conductivity (50 and 75 mL, 25 °C and readings made 2, 4, 6, 8, and 24 hours after beginning the test), speed of germination index, and seedling emergence in sand substratum in the laboratory (26 ± 3 °C) and daily seedling counts between the 7th and the 21th day after sowing. The treatment replications were distributed in the laboratory according to a completely random design with four replications. Seedling emergence in the field data were analyzed according to a randomized complete block design. Treatment means were compared by the Scott Knott test, at the 5% level of probability. The tests for germination and first germination count, seedling emergence and first emergence count in the sand, and accelerated aging are useful to assess the vigor of seed batches of the piatã grass, and provide similar evidence to the seedling emergence in the field.

Alibertia edulis Rich. is a native species of the Brazilian Cerrado and can be used for reforestation of degraded areas. In addition, it produces edible fruits. The objective of this study was to evaluate the effect of substrates and water levels on the emergence, initial growth, and quality of seedling of A. edulis. The substrates tested were: latosol (L), latosol + sand (L + S = 1:1), latosol + sand + chicken manure (L + S1 + CM = 1:1:0,5), latosol + sand + chicken manure (L + S2 + CM = 1:2:0,5), and latosol + commercial substrate (L + C = 1:1); and the water retention capacities (WRC) tested were: 25, 50, 75, and 100%. The experiment was carried through in a completely randomized design and subdivided into a plot scheme, in which the plots represented water availability and the subplots represented the substrates. Latosol + commercial substrate at 100% of WRC provided the best conditions for emergence, initial growth and formation of seedlings of A. edulis. Sowing in the substrate Dystroferric Red Latosol isolated at 25% of WRC should not be used for the formation of seedlings of this species.

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Plukenetia volubilis is a species native to the Amazonia and has economic potential due to the high contents of polyunsaturated fatty acids and vitamins of the seeds; however, information about production of seedlings in nursery is scarce. Factors that contribute to fast emergence and generation of vigorous seedlings are desirable for plant production in the nursery. Therefore, this study aimed to identify the most favorable substrate and seed position for the production of P. volubilis seedlings. The seeds were sown in the following four positions: hilum facing up, hilum facing down, seed lying on its cotyledon suture, and seed lying flat on one of its cotyledon faces. The substrates were sand, vermiculite and commercial substrate. Treatments were distributed according to a completely randomized design in a 4 × 3 factorial arrangement (seed position and substrate) with three replicates of 25 seeds each. The following variables were evaluated: emergence percentage; first count of seedlings; number, width and length of leaves; plant height; stem diameter; dry matter of shoots and roots. It was concluded that the production of P. volubilis seedlings is not affected by either substrate or seed position at sowing. The substrates most favorable to the quality of P. volubilis seedlings were the commercial substrate and vermiculite, always for the positions of seed lying on its cotyledon suture, with faces parallel to tube walls, and seed lying flat on one of its faces.

The aim of this research was to evaluate the quality and photosynthetic metabolism of "uvaia" seedlings (Eugenia pyriformis Cambess.) on different substrates and water regimes. ), photosynthesis (µmol m -2 s -1 ) and efficiency of water use (µmol de CO 2 / mmol de H 2 O). Until their 150 th days, the seedlings had higher quality and photosynthetic metabolism when cultured with substrates containing latosol + sand + poultry litter on the two variations assessed and water retention capacity of 50%.

The rules for seed analysis do not have recommendations for conducting the germination test of Eucalyptus phaeotricha seeds. Thus, the aim of this study was to determine the best substrate, temperature, conduction time, and substrate moistening level for the germination test of E. phaeotricha seeds. First count of germination, germination, germination speed index and mean time of germination were evaluated. The first experiment was carried out in a completely randomized design, in a factorial scheme (6 x 2), corresponding to six temperature regimes (15, 20, 25, 30, 35 °C and 20-30 °C) and two substrates (paper and sand) with four replicates, and the means were compared by Tukey test at 0.05 probability level. In the second experiment, the germination test was installed with the most favorable substrate and temperature identified in the previous step, evaluating substrate moistening levels equivalent to 1.0, 1.5, 2.0, 2.5 and 3.0 times the dry weight of the substrate; due to the quantitative nature of the treatments, the data were subjected to regression analysis and curve fitting. The germination test of E. phaeotricha seeds should be conducted at 30 °C on paper, moistened with a water volume of 2.2 times the dry weight of the paper, with initial and final counts at 6 and 14 days after sowing, respectively.

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