Controlled deterioration test for evaluation of sunn hemp seed vigor

Abstract

-The controlled deterioration test is efficient for seed vigor evaluation of several species. However, the procedures conditions are incipient, especially in respect to tropical forages such as sunn hemp, which still does not have a standardized procedure. The objective of this research was to adjust the procedures for a controlled deterioration test in Crotalaria juncea L. seeds. For this, five commercial seed lots were evaluated for water content and initial physiological potential (germination test, first germination count, germination speed index, saturated salt accelerated aging with NaCl, electrical conductivity and seedling field emergence). For controlled deterioration test, the initial seed moisture content was adjusted to 18, 21 and 24% and, subsequently, the samples were exposed at 45 °C during 24 hours. Seed germination test was conducted with the use of sand as substrate. Evaluations were performed on the fourth, fifth and sixth day after sowing. The controlled deterioration test for sunn hemp seeds should be performed with 24% seed moisture content, at 45 °C during 24 hours, and the test evaluation on the fourth day after sowing.Index terms: Crotalaria juncea L., germination, physiological potential, test standardization.Teste de deterioração controlada para avaliação do vigor de sementes de crotalária RESUMO -O teste de deterioração controlada é eficiente para avaliar o vigor de sementes de diversas espécies. No entanto, as condições para realização desse teste são incipientes, principalmente quando se trata de forrageiras tropicais, como é o caso da crotalária, cujas informações sobre a adequação do teste ainda são escassas. Assim, o objetivo deste trabalho foi adequar os procedimentos para a execução do teste de deterioração controlada para sementes de Crotalaria juncea L. Para tanto, cinco lotes de sementes comerciais foram avaliados quanto ao teor de água e potencial fisiológico inicial (teste de germinação, primeira contagem, índice de velocidade de germinação, envelhecimento acelerado com solução saturada de NaCl, condutividade elétrica e emergência de plântulas em campo). Para o teste de deterioração controlada, o teor de água inicial das sementes foi ajustado para 18, 21 e 24% e, posteriormente, as amostras foram expostas a 45 °C durante 24 horas, postas para germinar entre areia, e avaliadas aos quarto, quinto e sexto dias após a semeadura. O teste de deterioração controlada em crotalária deve ser conduzido com sementes contendo 24% de teor de água, a 45 °C, durante 24 horas e a leitura realizada aos quatro dias após a semeadura.Termos para indexação: Crotalaria juncea L., germinação, potencial fisiológico, padronização de teste.

Ozone penetration in a column containing sunn hemp (Crotalaria spectabilis Roth) seeds and the effect on the quality

“…As it was possible to observe the results of electrical conductivity were not influenced by exposure to ozone and also showed higher values of electrical conductivity for both treatments and control. According to [34] normal values of conductivity of Sunn hemp seeds ranged from to 0 μS cm -1 g -1 , lower values compared to the control value of this study of 46 μS cm -1 g -1 . Accordingly, such behavior can be explained by the fact that rupture of the membranes, detected electrical conductivity test through the release of exudates, is a natural consequence of seeds, whose intensity varied according to the exposure time of (O 3 ) (Fig.…”

Accelerated aging as vigor test for sunn hemp seeds

“…For evaluation of the physiological potential of sunn hemp seeds, some vigor tests have been standardized and validated such as electrical conductivity and Seed Vigor Imaging System -SVIS ® (SILVA et al, 2012a), tetrazolium (SILVA et al, 2012b) and controlled deterioration (SILVA et al, 2015) tests. However, studies on accelerated aging test in sunn hemp seeds are still incipient.…”