Growth and fruiting of selected provenances of Moringa oleifera Lam. in South Eastern region of Kenya

Abstract

There is increasing narrowing of the genetic base of exotic species introduced in many parts of the world. This is causing a restricted genetic diversity and consequential loss of biotic and abiotic tolerance of these species. Hence, there is need to establish the genetic stability of such species for future genetic broadening. One such plant is Moringa oleifera Lam. which belongs to the family moringaceae; a monogeneric family of shrubs and trees consisting of 13 species and is native to India. M. oleifera is the most economically useful species in the genus and is widely cultivated and naturalized in tropical and subtropical areas and in over 60 countries worldwide. In Kenya, M. oleifera is widely cultivated in coast and some parts of Eastern Kenya. A provenance trial was set up at South Eastern Kenya University (SEKU), located at Kwa Vonza location, lower Yatta Sub-County, Kitui County. The aim of the provenance trial was i) to determine whether the collected Moringa exhibited different growth and fruiting habits and ii) if so, select the best performing provenances for large-scale propagation of the species in Kenya. The trial involved fifteen provenances selected from a wide geographical region in Eastern and Coastal regions of Kenya. Each provenance consisted of 200 seedlings at a spacing of 2m by 2m and was replicated three times. The experiment was laid in a randomized complete block design (RCBD). Growth data (diameter and height), fruiting and fruit maturation were measured for a period of 12 months. Monthly growth data were used to generate horizontal and vertical growth curves. Duncan Multiple Range Test (DMRT) and test of homogeneity of variances were used to detect existence of statistically significant differences in the fifteen provenances. The results indicated statistically significant differences (p<0.05) between the provenances with the Mwakiki provenance being the most significantly different and the Mackinnon one being the least. Intra-seasonal fruiting and fruit maturation peaked in the months of November and December. Pearson and Spearman correlation analysis showed very strong positive correlations between growth and yield traits. The results also showed that the Mwakiki provenance had a stable performance in the three traits studied and is recommended for adoption especially where fruit production is the preferred end product. Molecular analysis of all the species should also be done to determine the genetic base status and correlate them with this phenotypic analysis.