Primary root emission and electrical conductivity test for wheat seed vigor evaluation

Primary root emission and electrical conductivity tests are rapid tests used to estimate the seed vigor of various species. However, few studies are directed to wheat seeds. This research aimed to evaluate the efficiency of the primary root emission and electrical conductivity tests to evaluate the vigor of different cultivars and wheat seed lots. Seeds from six cultivars represented by one lot each and five lots from cultivar CD 150 were used. Primary root emission at 20 °C and 25 °C after 24, 48, and 72 h and conventional and modified electrical conductivity with 2 and 4 g of seeds immersed in water at 25 °C for 6, 16, and 24 h, were compared with the following tests: germination, first germination count, accelerated aging, field and sand emergence and emergence speed index. A completely randomized design was used for laboratory tests. A factorial scheme was used for the primary root emission and modified electrical conductivity tests. Data were subjected to analysis of variance and means compared by the Tukey test (p≤ 0.05). A simple correlation analysis was performed between the tests and the seedling emergence percentage in the field. The primary root emission test (> 2 mm) at 20 or 25 °C for 48 or 72 h is efficient for evaluating the physiological potential of wheat seeds and correlates with seedling emergence in the field. The electrical conductivity test conducted using either the traditional or modified methodology is not effective in assessing the vigor of wheat seeds.