Influence of temperature and watering frequencies on seed germination and seedling growth of Ornithogalum longibracteatum and Tulbaghia violacea

The effect of temperature and watering frequencies on seedling growth were investigated in Ornithogalum longibracteatum and Tulbaghia violacea. Temperature had a significant influence on seed germination with low (10 °C) and high (40 °C) temperatures resulting in poor germination in both species. The optimum temperature for seed germination of O. longibracteatum and T. violacea was 22.9 and 26.8 °C, respectively. Seedling survival rate for both species was higher at temperatures ranging from 10 to 25 °C. Bulb fresh weight of seedlings grown at 15-25 °C was significantly higher than for seedlings subjected to 30 and 35 °C. Leaf length increased with higher temperature. The highest number of roots was recorded at 25 °C in both species. Watering had a pronounced positive effect on the seedling survival percentage and seedling growth of O. longibracteatum and T. violacea. Watering three times a week (W3) resulted in rapid seedling growth compared to watering once or twice a week. These findings suggest that a combination of temperature (25 °C) and frequency of watering of the seedlings will result in better seedling quality for field planting.