Estimation of Optimum Water Requirement and Frequency of Watering for Different Tree Seedlings at Bako Agricultural Research Center Nursery Site

Abstract

Determining water requirement and application frequency of tree seedlings is crucial to use available water effectively. This study estimated the Optimum water requirement and application frequency of tree seedlings: Grevillea robusta, Moringa olifera and Cordia africana at nursery site for the two consecutive years. The experiment was implemented during off-season; because of the objective of the study was to determine amount of water and frequency required for normal growth tree seedlings at nursery stage. Three different water application (1, 1.5, and 2 liters) and two irrigation frequencies (watering twice daily and watering twice after one day) and the control (Local practices) were combined with tree species. Seeds were sown directly into polythene bags in the traditional nursery site. Different growth parameters were collected and evaluated to estimate the optimum water requirement and watering frequency of different tree seedlings at nursery site. Growth parameters: root collar diameter (cm), height (cm), root depth (cm) and survival rate (%) were assessed during the nursery stage. The growth parameters measured were subjected to Analysis of Variance (ANOVA). The means were separated by Least Significant Difference (LSD; P ≤ 0.05). The result reveals that significant difference (P≤0.05) was observed among the three tree species growth parameters; root collar diameter, height and survival rate under different watering applications and irrigation frequencies. The average potential evapotranspiration of study area over the two consecutive years were 47 mm/month. The result indicated that, the growth performance of Moringa olifera and Grevillea robusta were better when watered twice daily with 1.5 liters of per a given plot. The growth performance of Cordia africana was good performed when watered twice after one day with 2 liters of water per a given plot. Also the result showed that Moringa olifera watered twice daily with 1.5 liters had the highest height of 50.74 cm followed by Moringa olifera watered twice after one day with 2 liters had height of 45.35 cm and while Grevillea robusta watered twice after one day with 1 liters had the least height 10.73 cm. The study therefore recommends that Moringa olifera and Grevillea robusta seedlings watered twice daily with 1.5 liters and Cordia Africana seedlings watered twice after one day with 2 liters per plot of water availability should be adopted in the area where warm humid climate and high potential evapotranspiration, since it ensures good growth performance of those tree seedlings species.