Effect of spacing on growth performance and leaf biomass yield of Moringa stenopetala tree plantations

Moringa stenopetala is a multipurpose tree distributed naturally in the lowland dry lands of the southern part of Ethiopia. The tree has vital nutritional, industrial, and medicinal applications and is thus good for large scale and/or commercial plantations. However, its cultivation is limited to traditional practices by small holder farmers for food, fodder, shade, windbreak and medicinal value around homesteads and on farmlands. The aim of this study was to determine the effect of plant spacing on plant growth parameters and leaf biomass production of M. stenopetala. The study was conducted in Arbaminch zuria woreda of Southern Nation Nationalities and Peoples Region (SNNPR). Three planting spacings (0.5 x 0.5 m; 1 x 1 m and 2 x 2 m) were arranged in a randomized complete block design (RCBD) and the treatments were replicated three times. Survival%, rootcollar diameter (RCD), height and stem diameter of the trees in each plot were recorded at three monthly intervals from the 3rd to 15 months. Data for leaf biomass were collected at the age of 27, 32 and 48 months. The harvested leaves were then oven dried to determine the dry leaf biomass. Individual Moringa trees showed better growth performance at the wider spacing of 2 x 2 m. The mean RCD, plant height and stem diameter were 7.45 +/- 0.20 cm, 1.69 +/- 0.06 cm and 3.19 + 0.11 cm for the wider spacing, while 3.12 +/- 0.16 cm, 1.02 +/- 0.07 cm and 2.12 +/- 0.14 cm for the narrow spacing at the age of 15 months. The wider spacing produced the largest quantity of dry leaf biomass per individual plant (119.28 +/- 9.02, 143.85 +/- 10.29 and 249.8 +/- 24.220 g/tree, but the least quantity on hectare bases 298.20 +/- 22.54, 359.62 +/- 25.73 and 624.49 +/- 60.59 kg/ha) while the narrow spacing produced the smallest quantity per individual plant (48.36 +/- 5.10, 44.74 +/- 3.19 and 88.15 +/- 30.28 g/tree), but the largest quantity on hectare bases (1934.40 +/- 203.89, 1789.56 +/- 127.78 and 3526.01 +/- 1211.2 kg/ha) at the first, second and third harvest, respectively. This indicates that an increase in the plant spacing led to higher dry leaf biomass production per tree due to better plant growth, but the lesser the leaf biomass yields per hectare due to the lower planting density. The performance of M. stenopetala is promising and hence it can be considered for large scale and commercial plantation .