Evaluation of the adaptability, productivity, and leaf powder quality of eight Moringa oleifera cultivars introduced to a dry-hot climate of Southwest China

Abstract

Although Moringa oleifera is a globally recognized multipurpose plant, and its seed-oil has been identified as an industrial source for the manufacture of cosmetic emollient, there is however lack of conclusive data on its performance in China, which is the most northerly latitude of moringa distribution in the world today. The objectives of this study were to (i) determine the adaptability, and (ii) evaluate the yield potential of seed-oil and quality characteristics of leaf powder from eight M. oleifera cultivars (‘Mali’ [ML], ‘Kenya’ [KE], ‘USA’ [US], ‘Cuba’ [CU], ‘Bangalore’ [BL], ‘Calcutta’ [CT], ‘Taiwan’ [TW], and ‘Myanmar’ [PO]) in the dry-hot regions of southwest China from 2014 to 2015. Evaluated cultivars showed variations in the studied vegetative and reproductive growth traits i.e. tree height, canopy diameter, and the number of branches producing fruit (NBF), etc. The results showed that the PO cultivar had the highest total number of ripe fruit loads (NRF). Although the plants from the US cultivar had the maximum number of fruit settings (NTF), they produced the smallest NRF/NTF ratio, suggesting that plants from different geographical provenances differed in their adapting to varied environments and a severe physiological fruit drop in the US cultivar. Also, the evaluated cultivars showed differences in the studied fruiting traits and yield components i.e. the number of seeds per fruit pod (NSF), seed weight, seed yield, and seed oil content. Among the plants assessed, M. oleifera from the PO produced significantly higher (P < 0.05) seed and oil yields per hectare, with respective average values of 1025 kg·ha−1 and 321 kg·ha−1 throughout the two evaluation years. In addition, nutrient variability in leaf powder as a fodder resource was analyzed for crude lipid, crude protein, and fibre components contents. There were no significant differences (P < 0.05) between the eight cultivars in the crude fiber, crude lipid, ash or dry matter (DM) contents, but the CT and BL cultivars exhibited significantly (P < 0.05) higher crude protein levels and in vitro dry matter digestibility (IVDMD) concentrations. These findings suggested that the best varieties regarding seed oil yield and leaf powder quality may be the PO cultivar from Myanmar, and CT and BL cultivars from India, respectively.