Vigor tests in assessing the quality of signal grass seeds

Abstract

The correct assessment of the physiological quality of seed lots is necessary for the quality control program of companies. For such purpose, tests that detect differences in the physiological potential of seed lots and that meet the minimum market requirements. Thus, the study was conducted towards assessing the efficiency of laboratory tests in differentiating the quality of Brachiaria brizantha cv. Xaraés seed lots. Seeds from nine lots were assessed regarding water content, germination, first germination count, electrical conductivity and seedling emergence in sand in the laboratory (normal seedlings, first count and germination rate index), and the results were compared with those from the seedling emergence test conducted in the field. The experimental design used was completely randomized, with four replicates, and the Pearson correlation coefficient between the values from the germination, vigor and field seedling emergence tests was determined. The germination and seedling emergence in sand tests and the seedling emergence rate index efficiently assess the physiological quality of Brachiaria brizantha cv. Xaraés seed lots, providing data similar to those from seedling emergence in the field. Key words: Brachiaria brizantha. Germination. Forrage grass. Vigor tests. ResumoA avaliação correta da qualidade fisiológica dos lotes de sementes é necessária para o programa de controle de qualidade das empresas, para isso se utiliza testes que detectam diferenças no potencial fisiológico de lotes e que atendam às exigências mínimas para a comercialização. Assim, o trabalho foi conduzido com o objetivo de verificar a eficiência de testes de laboratório na diferenciação da qualidade dos lotes de sementes de Brachiaria brizantha cv. Xaraés. As sementes de nove lotes foram avaliadas quanto ao teor de água, germinação, primeira contagem de germinação, condutividade elétrica, emergência de plântulas em areia no laboratório (plântulas normais, primeira contagem e índice de velocidade de emergência) e os resultados comparados aos obtidos no teste de emergência de plântulas em campo. O delineamento experimental utilizado foi o inteiramente casualizado, com quatro repetições e determinado o coeficiente de correlação de Pearson entre os valores obtidos nos testes de germinação e de vigor e o teste de emergência em campo. O teste de germinação, emergência de plântulas em areia e índice de velocidade de emergência de plântulas em areia são eficientes na avaliação da qualidade fisiológica de lotes de sementes de Brachiaria brizantha cv. Xaraés, fornecendo informações equivalentes à emergência de plântulas em campo. Palavras-chave: Brachiaria brizantha. Germinação. Gramíneas forrageiras. Testes de vigor.

Accelerated aging for evaluation of vigor in Brachiaria brizantha ‘Xaraés’ seeds

“…The effectiveness of the traditional accelerated aging test or the saturated saline solution test for seed vigor evaluation was also observed through the correlation between the results of the accelerated aging test and the results obtained in evaluation of seed lot quality, especially when correlated with the seedling emergence test (Figure 1). The correlation of data of a vigor test with seedling emergence in the field is crucial for the test to be considered effective, since a vigor test should not only classify lots into different vigor classes, but should also be as near as possible to results of seedling emergence in the field (Marcos-Filho, 2015a;Melo et al, 2017).…”

Accelerated aging test for forage pea seeds

“…Seedling emergence in the field was used as a reference for the selection of vigor tests (MELO et al, 2017;SILVA et al, 2017), and it was possible to classify the performance of the lots in descending order of vigor from 1 to 10 and group them into four classes of vigor: high (lots 1 and 2), high-medium (lots from 3 to 7), low-medium (lots 8 and 9), and low (lot 10). This criterion was used because one purpose of the vigor tests is to evaluate the physiological quality of the seeds to differentiate the lots in terms of vigor level and predict seedling emergence in the field (COIMBRA et al, 2007;MARCOS FILHO, 2015a;OLIVEIRA et al, 2014;MELO et al, 2017;SILVA et al, 2017).…”

“…The correlation of data from a vigor test with the emergence of seedlings in the field is crucial to consider the test as efficient because, in addition to classifying lots into different vigor classes, it should be as close as possible to emergence of seedlings in the field (LOPES;FRANKE, 2010;MARCOS FILHO, 2015a;MELO et al, 2017;SILVA et al, 2017).…”

Discrimination of forage pea seed lots by means of multivariate techniques

“…It is worth noting that the tests of interest in the evaluation of lots in seed analysis laboratories, besides ranking the lots at vigor levels, must present results correlated with seedling emergence in the field (Marcos Filho, 2015). Therefore, seedling emergence in the field was used as reference for the selection of vigor tests (Melo et al, 2017;Silva et al, 2017). The performance of the lots was classified in descending order of vigor, from 1 to 10, grouping them into four vigor classes: high (lots 1 and 2), medium high (lots 3 to 7), medium low (lots 8 and 9), and low (lot 10).…”

“…The performance of the lots was classified in descending order of vigor, from 1 to 10, grouping them into four vigor classes: high (lots 1 and 2), medium high (lots 3 to 7), medium low (lots 8 and 9), and low (lot 10). This criterion was used because one of the purposes of the vigor tests is to evaluate the physiological quality of the seeds attempting to differentiate lots regarding the vigor level and to predict seedling emergence in the field (Marcos Filho, 2015;Oliveira et al, 2014;Melo et al, 2017;Silva et al, 2017).…”