Estimation of Cone Maturity and Effect of Temperature, Light, and Stress Conditions on Seed Germination of Cedrus deodara in Garhwal Himalaya

Maturity estimation before seed collection is necessary in reducing the costs of seed collection; it allows vigorous seeds to be collected, ensuring that maximum germination will be reached and producing quality planting stock. In addition to this, appropriate temperature, seed size, pH, light, and stress conditions also influence germination. Cones of Cedrus deodara were collected at different intervals to estimate the maturity of the cones. A seed germination test was conducted in the laboratory under constant temperature, seed size, pH, light conditions, and water and salinity stress conditions. Significant (p < 0.05) variations in cones, such as seed morphological characteristics, germination, and related parameters, of C. deodara at different maturity periods were observed. The morphological traits of cones, such as seed weight, seed length, seed width, and seed germination, increased with increasing maturity, while the cone weight, moisture contents, specific gravity, and seed moisture decreased with increasing maturity. A constant temperature of 15 °C to 20 °C (98.0% to 92.0%) and the use of large-sized seeds (99.0%) led to maximum germination. Lower concentrations of Polyethylene glycol (98.0%) and NaCl (78.0%) contributed to maximum seed germination. The germination of C. deodara is temperature-dependent and seed size, light, and high water and salinity stress significantly influence seed germination.