Resumen

ARAUJO, Roberto F et al. Electrical conductivity test for physic nut (Jatropha curcas L.). Idesia [online]. 2011, vol.29, n.2, pp.79-86. ISSN 0718-3429.  http://dx.doi.org/10.4067/S0718-34292011000200010.

ABSTRACT In order to have more accurate information of seed quality among different seed lots, it is necessary to supplement the data supplied by the germination test with other tests, making possible the selection of best lots for marketing and seeding establishment and among those tests the electrical conductivity test fits well to that purpose. For physic nut (Jatropha curcas L.), no information about electrical conductivity test methods is available in the literature. Thus, the aim of this research was to establish a standard method for testing the electrical conductivity of physic nut seeds leaking, testing different number of seeds, amount of water and soaking period. So, we used eight lots of physic nut seeds proceeding the electrical conductivity test with the following variations: 15, 25 or 35 seeds, soaked in 75 or 100 mL of distilled water at 25 °C, and the readings performed after 3, 6, 9, 12, and 24 hours of soaking. As a matter of fact, were determined the germination percentage and the seedling emergence rate. Based on the results and on the correlation coefficients calculated between the results of electrical conductivity test and emergence percentage, the most efficient methods were with 15 seeds under soaking in 75 mL of water, with readings after 6, 9 and 12 hours; 25 seeds under soaking in 75 mL of water, with readings at the same time mentioned before, but the most appropriate method to to distinguish physic nut seed lots with different physiological quality is the use of 15 seeds in 75 mL of water, with reading after six hours of its starting.

Palabras clave : Electric conductivity test; physic nut; vigor; seed.

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