An alternative procedure for evaluating the quality of castor seeds by the tetrazolium test

Abstract

The use of fast technologies, which also permit efficient decisions on seeds lots quality, is fundamental to the seed industry. Five seeds lots of “IAC 80”and five seeds lots “AL Guarani 2002” cultivars were used to test an alternative procedure for evaluating the seed quality of castor seeds by the tetrazolium test. Seeds lots characteristics were determined by tests of germination, first count germination, seedling emergence, speed emergence index and initial stand. The seeds were imbibed in water at 30°C for 3 h for the tetrazolium test and submitted to three preparation methods: (1) a bevel cut in the region opposite to the caruncle; (2) removal of the coats and a bevel cut in the region opposite to the caruncle; (3) removal of the coats and lateral cuts in the seed. After preparation, the seeds were immersed in 0.5 and 1.0% tetrazolium solutions for 6 h at 30°C. Imbibitions in water at 30°C for 3 h, followed by removal of the coats and lateral cuts in the seeds, with immersion in a 1% tetrazolium solution at 30°C for 6 h, is a suitable methodology for evaluating castor seed quality.