Effects of application of organic formulated fertiliser and composted Tithonia diversifolia leaves on the growth, yield and quality of okra

ABSTRACT The production of healthy food in a sustainable manner is a major challenge for agriculture. Pot experiments were conducted in an open field during the rainy season in 2017 and 2018 to study the effects of the application of composted leaves of Tithonia diversifolia (T) and organo-biodegradable (OBD+) formulated fertiliser on growth, yield and concentrations of minerals and bioactive compounds in okra. Treatments consisted of four application rates of composted Tithonia leaves (0, 10, 20 and 30 g 10 kg−1 soil) and three rates of organic-biodegradable (OBD+) formulated fertiliser (0, 10 and 20 g 10 kg−1 soil), which were combined and arranged in a complete randomised design with four replications. Performance and quality parameters of okra were measured. The application of the amendments significantly increased vegetative growth and yield parameters of okra, compared with the control, with the application of 30 T + 10 OBD+ resulting in the highest values for growth and yield. The number of days to flowering and fruiting of the okra was significantly reduced by the application of the organic amendments. The results also revealed that the concentrations of mineral elements and bioactive compounds in the okra fruits significantly increased with applications of 30 T + 20 OBD + and 30 T + 10 OBD +. Therefore, for improved vegetative and yield performance as well as accumulation of mineral elements and bioactive compounds, the application of 30 T + 10 OBD+ was considered as the most suitable for the cultivation of okra in the study area.