Effects of temperature, soil water potential, and seed applied super slurper on germination and seedling elongation of soybeans and sunflowers

Germination and seedling elongation of soybeans(cults : ‘Essex’ and ‘Williams’), and sunflowers cults. ‘Seed Tec’ 327 and ‘SIGCO 449’) were measured at three temperatures(15.0, 22.5, and 30.0 C) and four soil water potentials(-1.80, -0.50, -0.04, and 0.02 MPa), with and without treatment with super slurper. Measurements were made at 0, 1, 2, 4, and 8 days. Seedling moisture uptake and seedling development were affected by temperature, soil water potential, and cultivar of each of the two species. Super slurper did not significantly affect seedling growth. Highly significant positive correlations were found between seedling moisture content and seedling length. Negative correlations were found between seedling dry weight and the other dependent variables. Multiple regression equations for seedling moisture content of two species were developed as a function of cultivar, temperature, soil water potential, and interaction terms in germination time. Soybeans required more time to achieve the initial one cm of seedling length than sunflowers at the lower soil water potential(-1.80 MPa), but less time at the high soil water potential(-0.02 MPa).