To obtain seeds of high physiological quality, it is of paramount importance to define the ideal harvest moment, which oftentimes corresponds to the period when the physiological maturity is reached. This experiment aimed to study the maturation process and determine the best harvest season of maroon cucumber fruits (Liso Gibão cultivar), in order to reach the maximum physiological seed quality. The flowers were labeled during the anthesis and the fruits harvested at 14, 21, 28, 35, 42, 49 and 56 days after the anthesis (DAA). The fruits had their visual aspects registered by photography analysis and, later, the seeds were extracted for physical (water and dry matter contents) and physiological (germination, seedling emergence, emergence speed index, accelerated aging and electrical conductivity) analyses. It was observed that the seeds reach the maximum dry mass (8.08 mg seed-1) between 47 and 49 DAA. However, the seed physiological maturity, characterized by a maximum germination (70 %) and vigor, occurs at 56 DDA. The best season to harvest seeds with a higher physiological quality takes place from 49 to 56 DDA, when the fruits present a yellowish color.

Natural factors such as salinity act directly on seed germination and vigor and, consequently, affect the establishment and development of seedlings in the field. In view of the above, the objective of this study was to assess the effect of saline stress on the germination and vigor of seeds from black bean cultivars. The study was conducted at the Seed Analysis Laboratory of the State University of Montes Claros, Janaúba-Minas Gerais, Brazil. The experimental design was completely randomized, in a 2 × 5 factorial arrangement (two cultivars × five osmotic potentials), with four repeats of 50 seeds per treatment. Bean seeds from cultivars Campeiro and Esteio were used, with sowing carried out on germitest paper rolls moistened at five osmotic potentials via sodium chloride solutions (NaCl): 0.0 [distilled water]; -0.3; -0.6; -0.9 and -1.2 MPa. Seed rolls were kept in a digital germinator, and the germination and vigor percentages of the seeds were determined by first germination count, germination speed index (GSI), and fresh and dry mass of seedlings. The germination and vigor of seeds from common-bean cultivars, black commercial type, are negatively affected under saline stress caused by NaCl solution with osmotic potential lower than -0.6 MPa. The seeds of the studied cultivars showed a different behavior regarding saline stress conditions, and cultivar Campeiro proved to be more tolerant to saline stress in relation to Esteio during the germination process and seedling formation.

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Saline stress is a condition that causes changes in physiological performance in several species and even in cultivars of the same species. Thus, this studyaimed to evaluate the physiological performance of black bean cultivars to salt stress. A completely randomized experimental design was used in a factorial scheme with two cultivars (Mataço and BRS Paisano) and five osmotic potentials simulated with sodium chloride solutions (control = 0.0; -0.2; -0.4; -0.6 and -0.8 MPa), in four replications of 50 seeds per treatment. The variables related to germination, first germination count, germination speed index, and shoot length were evaluated. There were significant interactions (p <0.05) for all variables analyzed. In general, it is concluded that the physiological performance of the seeds of black bean cultivars is affected under simulated saline stress by NaCl solution with an osmotic potential below -0.2 MPa.