The growth of Balanites aegyptiaca (L.) seedlings under varied watering intervals in the nursery
Water stress has a strong influence on the physiological functions of tree crops which adversely affects the growth and yield of tree plants. Drought and soil fertility are the major factors that influence seedling survival and growth in arid areas, thus it is of paramount importance to establish optimum water requirements for tree seedlings in order to promote growth. In line with this, an investigation was carried out to assess early growth behaviours of Balanites aegyptiaca when exposed to varied watering intervals in the screen house. Two weeks old seedlings in polythene bag (2kg) containing the standard potting mixture as growing media were used for the experiments. Seedlings were exposed to 4 different watering intervals (once daily, once after 3, 7 and 14 days) and 200ml of water was administered per each seedling based on the watering frequency for 12 weeks. Ten seedlings were allocated per watering frequency and replicated 5 times in a completely randomized design. Data was collected on stem height, collar diameter, number of leaves and seedlings dry weights. Net assimilation rate, relative growth rate and absolute growth rate were also calculated. Data was analysed with analysis of variance and the significantly different means were separated with Duncan Multiple Range Tests (p<0.05). The result revealed a significant effect of water stress on seedlings growth of B. aegyptiaca where seedlings that received water once daily and once after 3 days produced highest growth in all the variables measured. Administering 200ml of water per seedling once after 3 days is therefore recommended for the improved growth of B. aegyptiaca in the nursery.
Key words: water stress, seedling growth, B. aegyptiaca, nursery, regeneration