Core Ideas The soaking kinetics of seeds of six cultivated species was modeled.Morphological and physical properties of seeds affected the water absorption.Two models were adapted in order to capture the third phase of the soaking process. Several models can be used to describe the seed soaking curve, which, under optimal conditions, occurs according to a three‐phase pattern. Among these models, the Peleg model stands out by its wide use. However, phase III (of germination itself) is not captured by this and other common models in seed soaking curves. The soaking curves of pea (Pisum sativum L.), lentil (Lens culinaris Medik.), onion (Allium cepa L.), welsh onion (A. fistulosum L.), maize (Zea mays L.), and millet [Pennisetum glaucum (L.) R. Br.] seeds, diverging for physical and morphological properties, were obtained with the following objectives: (i) to propose models to fully describe the kinetics of soaking of seeds, capturing the three stages of the process; (ii) to identify the most appropriate model for each species; (iii) to identify the phases of the soaking process; (iv) to relate physical and morphological properties of seeds, such as bulk density, sphericity, with the soaking kinetics. Five models were fitted: third degree polynomial, Peleg model, logistic model, an adaptation of the logistic model and an adaptation of the Peleg model, both adaptations with the addition of an exponential term with two parameters. The species P. sativum (pea) and L. culinares (lentil) did not present the third stage of the process. In this case, the Peleg model shall be used. On the other hand, the other species presented the three phases. The adaptation of the Peleg equation was quite effective in modeling the seed soaking curve of those species. The water absorption capacity is negatively correlated with the seed's sphericity and density.

-Vigor tests are important tools for verifying the physiological potential of seed lots; however, various aspects can interfere in the consistency of the test results. The search for less subjective procedures has drawn the interest of researchers. The aim of this study was to adapt the methodology of the controlled deterioration test and verify the efficiency of the Seed Vigor Imaging System (SVIS ® ) to evaluate the vigor of crambe seeds. Initially, seed moisture content was determined and germination and vigor were evaluated in five seed lots. For the controlled deterioration test, the seed moisture content was adjusted to 18%, 20%, and 22%, and the results were interpreted at four and five days after sowing. The controlled deterioration test should be performed with initial adjustment of seed moisture content to 18%, and the germination test should be evaluated on the fifth day after sowing. SVIS ® provided information on the vigor index and the length and uniformity of seedling development. Computerized image analysis is effective in evaluating the vigor of crambe seeds, and the uniformity of seedling development parameter offers the most consistent data.Index terms: Crambe abyssinica, software, seed vigor.Teste de deterioração controlada e uso do sistema automatizado de análise de imagens de plântulas (SVIS®) na avaliação do potencial fisiológico de sementes de crambe RESUMO -Os testes de vigor são ferramentas importantes para aferir o potencial fisiológico de lotes de sementes, porém, vários aspectos podem interferir na consistência dos resultados desses testes, tendo a busca por procedimentos menos subjetivos despertado o interesse dos pesquisadores. Este trabalho foi realizado com o objetivo de adequar a metodologia do teste de deterioração controlada e verificar a eficiência do sistema automatizado de análise de imagens de plântulas (SVIS ® ) na avaliação do vigor de crambe. Inicialmente, cinco lotes de sementes foram submetidos à determinação do teor de água e avaliações de germinação e vigor. Para o teste de deterioração controlada, o teor de água das sementes foi ajustado para 18, 20 e 22%, e a interpretação dos resultados realizada aos quatro e cinco dias após a semeadura. O teste de deterioração controlada deve ser realizado com ajuste inicial do teor de água para 18% e a avaliação da germinação realizada no quinto dia. O SVIS ® forneceu informações sobre o índice de vigor, comprimento e uniformidade de desenvolvimento de plântulas. A análise computadorizada de imagens é eficiente para avaliar o vigor de sementes de crambe, sendo o parâmetro uniformidade de desenvolvimento de plântulas o que apresenta dados mais consistentes.Termos para indexação: Crambe abyssinica, software, vigor de sementes.

Core Ideas Dehydration of C. adamantium seed is followed by a decrease in seed viability and vigor. Physical injury damage and internal free space increase as the seed dehydrates. X‐ray images can be used to evaluate the internal morphology of C. adamantium seed. Internal morphology is related to germination and vigor. Sensitivity to desiccation is a characteristic that hinders the ex situ conservation of seeds, which can result in reduction of viability and vigor as the water is lost. Dehydration is sometimes followed by the occurrence of injuries and retraction of tissues. In this study, radiographic images of Campomanesia adamantium (Cambess.) O. Berg. seed were used to evaluate changes caused by desiccation in the internal morphology and their relationships with germination and vigor. The initial water content of the seed was determined (48%) and adjustments were made to obtain samples with water content of 36, 30, 27, 24, and 21% (wet basis). Evaluations of germination, germination first count, speed germination index, mean germination time, and seedling length were performed. Individual radiographs of the seed were obtained using digital x‐ray equipment. The images were used to identify cracked seed (CS) and to determine the internal free space (IFS). Data were subjected to analysis of variance and the effect of desiccation studied through polynomial regression. Seed viability and vigor decreased linearly as the seed desiccated. The results indicated that IFS and CS are positively associated with the loss of water. The loss of germination and vigor of C. adamantium seed is related to changes in the internal morphology during desiccation, which can be identified by x‐ray imaging.

RESUMO: O processo de germinação tem início com a embebição, por ocasião da água disponível, a qual desencadeia uma sequência de mudanças metabólicas que culminam com a protrusão da raiz primária, em sementes viáveis. Pela organização do sistema de membranas celulares, um método que pode indicar o nível de vigor das sementes é a condutividade. Objetivouse avaliar e modelar o processo de embebição de sementes de grão-de-bico, além de estabelecer metodologia eficiente para volume de água, tempo de embebição e número de sementes no teste de condutividade elétrica. Foram utilizados oito lotes, sendo quatro da cultivar BRS Aleppo e quatro da cultivar Cícero que foram submetidos ao teste de germinação e vigor para caracterização inicial. A condutividade elétrica foi conduzida com subamostras de 50 e 75 sementes utilizando 75 e 100 mL de água deionizada, e avaliou-se os períodos 2, 4, 8, 12, 18, 24 e 30 h, mantidas à temperatura de 25 °C. O experimento de condutividade elétrica foi em delineamento inteiramente casualizado com quatro repetições. Para cinética de embebição foi ajustado o modelo de Peleg. A metodologia mais adequada foi a utilização de 75 sementes, volume de 100 mL de água durante 30 h. O modelo de Peleg foi eficiente na descrição do processo de absorção de água, ainda que haja diferenças no potencial fisiológico dos lotes. Palavras-chave: Cicer arietinum L.; lixiviados; metabolismo; modelo de Peleg; vigorElectrical conductivity test and soaking of chickpea seeds ABSTRACT: The germination process begins with the imbibition, during the available water, which triggers a sequence of metabolic changes that culminate in the protrusion of the primary root into viable seeds. By the organization of the cell membrane system, a method that can indicate the level of seed vigor is the conductivity. The objective of this study was to evaluate and model the process of imbibition of chickpea seeds, in addition to establishing an efficient methodology for water volume, imbibition time and number of seeds in the electric conductivity test. Eight lots were used, four of the BRS Aleppo cultivar and four of the Cícero cultivar, which were submitted to the germination and vigor test for initial characterization. The electrical conductivity was conducted with 50 and 75 seed subsamples using 75 and 100 mL of deionized water, and the periods 2, 4, 8, 12, 18, 24 and 30 h were maintained at 25 °C. The experiment of electrical conductivity was in a completely randomized design with four replicates. The Peleg model was adjusted for imbibition kinetics. The most appropriate methodology was the use of 75 seeds, volume of 100 mL of water for 30 h. The Peleg model was efficient in describing the process of water absorption, although there were differences in the physiological potential of the lots.

-Several factors affect the electrical conductivity test efficiency, with emphasis given to the initial water content and the temperature during imbibition. This study aimed to evaluate the effect of the initial water content of pea seeds and the temperature on the electrical conductivity test efficiency. Six lots of 'Mikado' pea were used, which were previously tested for initial characterization. In the first trial, based on the initial value of the samples, the seed moisture content was adjusted to 9, 11, 13 and 15% and then the seeds were submitted to the electrical conductivity test. In the second trial, the water for seed imbibition was kept for 24 hours at 10, 15, 20, 25 and 30 ºC, and after that time the seeds were added and soaked for other 24 hours at the temperatures already mentioned. It was observed that initial seed moisture content and water temperature during imbibition influenced the results of the electrical conductivity test. This test should be carried out with distilled water, previously maintained for 24 hours at 25 °C for temperature stabilization. Then, the seeds with seed moisture content between 11 and 15% should be put to soak at 25 °C, and maintained at this temperature for 24 hours.Index terms: Pisum sativum, imbibition, exudates, vigor.Temperatura e teor de água afetam o teste de condutividade elétrica em sementes de ervilha RESUMO -Vários fatores interferem na eficiência do teste de condutividade elétrica, com destaque para teor de água inicial e temperatura durante a embebição. Este trabalho objetivou avaliar o efeito do teor de água inicial das sementes de ervilha e da temperatura na eficiência do teste de condutividade elétrica. Utilizaram-se seis lotes de ervilha 'Mikado' que foram submetidos a testes para caracterização inicial. No primeiro ensaio, baseado na umidade inicial das amostras, foi ajustado o teor de água para 9, 11, 13 e 15% e, posteriormente, foram submetidas ao teste de condutividade elétrica. No segundo ensaio, a água para embebição das sementes foi mantida por 24 horas a 10, 15, 20, 25 e 30 °C e, após este período, adicionou-se às sementes e foram colocadas para embeber por mais 24 horas nas referidas temperaturas. Observou-se que teor de água inicial e temperatura da água durante a embebição influenciaram nos resultados do teste de condutividade elétrica. Este teste deve ser realizado com água destilada previamente mantida por 24 horas a 25 °C para estabilização da temperatura, posteriormente as sementes, com teor de água entre 11 e 15%, colocadas para embeber na temperatura de 25 °C, mantidas nesta temperatura por 24 horas.Termos para indexação: Pisum sativum, embebição, exsudatos, vigor.

The size of fruits and seeds can affect the seed germination process and aspects related to the vigor of the seedlings formed. Our aim was to characterize fruit and seed biometrics, evaluate the effect of seed size on soaking and the effect of seed size and temperature on the germination and vigor of Campomanesia adamantium . The fruit was evaluated to determine longitudinal diameter, transverse diameter, fresh mass and empty, full and total seed quantities. The seeds were sorted into small, medium and large classes and then measured for length, width, thickness and mass. Seeds from each class were submitted to the germination test at 25 and 30 °C. The germination and vigor (first count, germination speed index, mean germination time and seedling length) data were evaluated by analysis of variance and a means test. Seeds from each size class were weighed repeatedly during soaking. The soaking data were fit to logistic and Peleg models and best fit curves with confidence bands were constructed to compare the effect of seed size. Fruit morphology showed high intraspecific variability. Germination was not affected by seed size or test temperature. Large seeds yielded taller seedlings while the 25 °C germination temperature produced the highest seedling growth rate. The small and medium seeds showed all three phases of the soaking process. Finally, soaking was initially slower for the large seeds than for the small and medium seeds.

Snap beans are one of the ten most consumed vegetables in Brazil, and there are few cultivars available in the Brazilian market. This study aimed to evaluate the seed yield of 20 snap beans genotypes under conventional and organic systems under Brazilian Cerrado conditions. Plant height, number of seeds per pod, weight of 100 seeds and yield were evaluated. For plant height and number of seeds per pod, the 20 genotypes were equal in the conventional cultivation system. In the organic system, the 20 genotypes formed two distinct groups regarding these variables. In the conventional system there were no significant differences between genotypes regarding the weight of 100 seeds, the mean mass in this system was 19.08 g, but there were differences in the organic system. Regarding yield, there was significant difference between the genotypes for both cultivation systems, organic and convetional. Production of snap bean cultivars in the organic system was shown as viable and promising. The genotypes Amarelo Japonês, Hab 1 and Tendergreen Improved stood out among the most productive in both systems.

The objective of this work was to establish the temperature and the period of exposure needed to perform the traditional accelerated ageing test with saturated NaCl salt solution on chickpea seeds. Eight seed lots from two cultivars, including four seeds each, were subjected to germination and vigour tests for initial characterization. Following the methodology of the traditional accelerated ageing test. The seeds were placed on stainless steel screens in boxes with 40 mL deionized water. They were kept at 41 and 45º Celsius for 24 and 48 hours. Furthermore, the accelerated ageing test using [40 g of NaCl in 100 mL of water, thus providing 76% of relative humidity in air] NaCl (salt) solution in place of the deionized water was performed. Aged seeds were sowed in germination paper and kept in a germination chamber at 41º and 45º Celsius. The evaluations were performed five and eight days after sowing. The statistical analysis was performed with a completely randomized design and four replications. The traditional ageing of both cultivars showed a water content higher than the tolerated limits at 48 hour period and 41 and 45 °C. In the saturated saline test, the cultivar BRS Aleppo produced consistent results at temperatures 45 °C for 24 h. The cultivar Cícero showed a low correlation with the initial characterization as the results of accelerated ageing. Thus, for ‘BRS Aleppo’, the recommended accelerated ageing methodology was application of saturated saline solution, when seed exposed to 41 °C for 24 hours with germination evaluation at the first count date. For 'Cicero', satisfactory results were not obtained, and new studies are required to establish a methodology.