Phenolphitalein-exudate pH test in the evaluation of Crateva tapia L. seed viability

The success of reforestation depends on seed quality, making it essential to assess their physiological potential. This evaluation can be carried out through vigor tests, such as the exudate pH test, which is considered quick and cost-effective. The objective of this study was to evaluate the exudate-phenolphthalein pH test in assessing the viability of seed lots of Crateva tapia L. A completely randomized design in a 2 × 5 × 5 factorial scheme was used, with two temperatures (20 and 30 °C), five soaking periods (30, 60, 90, 120, 150 min), and five seed lots (I: matrix 0, II: matrix 99, III: matrix 100, IV: matrix 101 from Juarez Távora, and V: matrix Remígio). In the Seed Analysis Laboratory, the physical and physiological characteristics of the seeds were determined, followed by exudate pH and germination tests to verify the results. The data were subjected to analysis of variance, and the means were grouped by the Scott-Knott test. Lot I showed the lowest vigor, a result confirmed by the exudate pH test. The tests for first count, percentage, and germination speed index were effective in evaluating seed lot quality. The pH test, conducted at 20 °C for 30 min, proved efficient in analyzing seed viability.