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.

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.

Our objective was to evaluate the occurrence of mechanical damage in chickpea seeds with the combination of two harvester speeds (2.5 and 3.5 km.h-1) and three adjustments for rotor rotation speeds (500, 700, and 850 rpm). Harvesting was carried out in a seed production field. Seeds were evaluated for purity, germination (G), first count (FC), germination speed index (GSI), hypochlorite, electrical conductivity, and tetrazolium tests. There was an effect of harvester speeds on seed physiological quality for the first count (FC), germination (G), germination speed index (GSI), especially when combining with high rotor rotation speed. In these cases, the speed of 2.5 km.h-1 resulted in lower values. This harvester speed also had worse results when combining with 850 rpm for purity and hypochlorite tests. The tetrazolium test was not efficient in identifying differences in seed quality. There was no significant interaction between harvester speeds and rotor rotation speeds for the conductivity test. Evaluating the harvester speed’s isolated effect (3.5 km.h-1), we identified problems in seed vigor due to the higher value of exudates in the electrical conductivity test. Low harvester speed (2.5 km.h-1) associated with high rotor rotation speeds (700 and 850 rpm) causes a reduction of the physical and physiological quality of seeds.

O presente trabalho objetivou estabelecer (atualizar) a metodologia para execução do teste de germinação em sementes de grão-de-bico, no que se refere ao substrato, temperatura ideal e data da primeira contagem. Para tanto, foram realizados três ensaios: I) avaliação de substrato; II) avaliação da temperatura de exposição das sementes durante a germinação; e III) averiguação da data de primeira contagem. Os experimentos foram organizados em delineamento inteiramente casualizado, esquema fatorial 6 x 3 (cultivares x substratos), para o ensaio I e 6 x 4 (cultivares x temperatura) para o ensaio II, ao final foram realizadas as análises de variâncias e as médias comparadas pelo teste de LSD. Para o ensaio III foi elaborado gráfico de contagem de plântulas normais, avaliando a porcentagem de germinação. Os parâmetros analisados foram: germinação, índice de velocidade de germinação e tempo médio de germinação, nos ensaios I e II. No ensaio III apenas germinação. Foram observadas maiores porcentagens de germinação, e aumento na velocidade de germinação quando utilizado o substrato rolo de papel. As temperaturas extremas não se mostraram favoráveis ao processo de formação de plántulas. De acordo com os resultados obtidos recomenda-se a utilização de rolo de papel, à 20 °C e com data de avaliação da primeira contagem aos 6 dias após a semeadura para teste de germinação.

The chickpea crop is grown predominantly in the arid and semi-arid regions of the world. India is the largest producing country, in Brazil production is scarce, leading the country to import almost all of what is consumed. Grains are a good source of carbohydrates, proteins and even essential amino acids. One of the first steps towards profitable production is knowledge about the availability of high-quality seeds. The germination test, evaluates the formation of normal seedlings in ideal conditions, so it must be associated with vigor tests, rapid and uniform germination of the seeds, simulating adversities in the field. Among the tests used, accelerated aging and electrical conductivity are common, as well as the study of the water absorption curve by the seeds. Accelerated aging is based on high temperature and humidity, real stress conditions in the field or in storage. For chickpeas, it is recommended to use saturated saline solution, 24 h exposure, at 41 ºC and evaluation at the first count. The electrical conductivity is determined by the amount of leachate, the higher the values, the less vigor. The most suitable methodology is the use of 75 seeds, volume of 100 mL of water, during 30 h of soaking. The process of water imbibition by the seeds occurs according to a three-phase pattern. In studies with the species, there was no clear definition between the three phases. However, the Peleg model adjusted to the imbibition data of the analyzed cultivars. There are other efficient ways, not yet described, for evaluating the physiological potential in this species, among them the tetrazolium test, images from scanners and radiographs, or even magnetic resonance of seeds. Although these tools require expensive equipment, they can streamline and increase the accuracy of seed analysis.