Tetrazolium test for evaluation of the physiological quality of seeds of Vigna unguiculata (L.) Walp.

Abstract

The aim of this study was to develop appropriate procedures for carrying out the tetrazolium test in order to verify viability in seeds of the cowpea. The following were evaluated: two temperatures, 35 and 40 degrees C; three concentrations of tetrazolium, 0.05, 0.075 and 0.1\%; and three periods, 90, 150 and 210 minutes. At the same time, tests for germination, seedling emergence, electrical conductivity and accelerated aging were conducted in order to establish criteria for assessing viability and vigour. The seeds were divided into two groups, viable and nonviable, which displayed an appropriate relationship to emergence. Evaluation of the viability and vigour of cowpea seeds by means of the tetrazolium test is efficient after preconditioning by direct immersion in water for 16 hours at 25 degrees C, and when using a tetrazolium solution at a concentration of 0.05\% for 210 minutes at 40 degrees C.