Seed Germination Modeling of Guar (Cyamopsis tetragonoloba), Affected by Temperature and Water Potential: Hydrothermal Time Model

The present study tries to quantify germination response of Guar (Cyamopsis tetragonoloba) to temperature and water potential. Performed in Vali-e-Asr University laboratory in 2020, it is a completely randomized design in a factorial arrangement with four replications. It aims at quantifying the rate of Guar germination in response to temperature, and water potential. The seeds have been germinated at seven temperatures (5, 10, 15, 20, 25, 30, and 35°C) and six water potentials (0, -0.2, -0.4, -0.6, -0.8, and -1 MPa). The results reveal that the Beta function is suitable for describing the response of seed germination temperature, and water potential. Under different water potentials, base, optimum, and maximum temperatures have been 7.3-12°C, 22.1-25.8°C, and 32.2-36°C, respectively. The hydrothermal time parameters are 268.3 bar °C h, -1.103 MPa and, 8.36°C for ɵHT (hydrothermal time constant). The data obtained from these models can be used to establish and manage guar for cultivation in different areas.