Citrullus lanatus cv. citroides is a widely used species as a food and water source for ruminants in regions with low rainfall such as the Brazilian Semi-arid. Studies on adequacy methodology involving the physiology of this species have been aimed at producing more vigorous seeds that originate healthy seedlings with uniformity and higher yield. However, the objective of this work was to adapt the methodology of the electrical conductivity test for forage watermelon seeds. Five seedlots were initially characterized for quality by tests of: germination, First germination count, germination speed index, seedling length, shoot, root and seedling dry mass, emergence in sand and emergence speed index. Two immersion volumes (50 and 75 mL) of deionized water, three soaking temperatures (25, 30 and 35 °C) and six immersion periods (1, 2, 4, 8, 12, 24 hours) were evaluated. The obtained data were analyzed according to a completely randomized design with two replications of 50 seeds using the analysis of variance, the 5% F-test and the comparison between the means of the seedlots using the Tukey test at 5% probability. The electrical conductivity was adequate in the volume of 75 mL1 of water with an immersion period of one hour, and temperatures of 25, 30 and 35 °C, demonstrating efficiency in proving the physiological quality of C. lanatus seeds.

Keywords: Seeds, physiological quality, vigor.