pH Exudate Test for Determining the Viability of Araucaria angustifolia Seeds

This study aimed to verify the efficiency of methods of pre-conditioning and periods of water immersion to perform the pH exudate test to evaluate the viability of Araucaria angustifolia seeds. Three pre-conditioning methods (whole seed, seed longitudinally sectioned, excised embryo) and three water imbibition periods (30, 60 and 90 minutes) were tested, and the solution color was evaluated. Additionally, the seeds were artificially aged for four and eight days at 40 degrees C. The viability was higher in embryos excised, after 30 minutes of imbibition, showing high coefficient of correlation with the germination and tetrazolium tests. Seeds at advanced stage of deterioration should be evaluated by associating the solution color with the tissue aspect. In conclusion, the pH exudate test is efficient to evaluate the viability of A. angustifolia seeds, and it should be performed using excised embryo imbibed in water for 30 minutes.