Seed Germination and Early Seedling Growth Responses to Drought Stress in Annual Medicago L. and Trifolium L. Forages

Climate change in the Mediterranean-like regions of South Africa has resulted increased rainfall variability, a delayed start to wet winter season, and occurrences out-of-season summer events. These changes bioclimatic conditions are predicted become more pronounced and, therefore, could result poor seedling establishment false breaks from soil seed bank, followed by desiccation annual medic clover pastures. This study therefore aimed quantify compare responses three Medicago species five Trifolium drought stress imposed at germination, establishment, early growth stages. Three separate controlled trials were conducted. Firstly, seeds germinated germination chambers constant temperatures ranging 5 30 °C, °C increments, with osmotic treatments within each temperature, was recorded daily. For second experiment, planted 100, 70, 50, 30% soil’s moisture-holding capacity without subsequent watering, emergence third one-month-old seedlings subjected two water-limitation periods (15 or days), their morphological measured. The results these experiments indicated that differed significantly drought, best-performing often when different development Five species—M. polymorpha L., M. truncatula Gaertn., T. alexandrinum vesiculosum Savi., subterraneum L. ssp. subterraneum—were able tolerate incidences better than other thus, should be prioritized for further research into variation tolerance between cultivars species.