Effectiveness of different formulations of moringa extracts against postharvest papaya diseases

S. Langa, S.Z. Tesfay, N.C. Mbili, L.S. Magwaza, A. Mditshwa
Synthetic fungicides have been found to have human and environment health drawbacks and as a result; plant extracts are becoming a promising alternative for controlling postharvest diseases of fruits. Therefore, this study investigated the effect of moringa extracts on fungal growth of different papaya diseases. Colletotrichum gloeosporioides, Rhizopus stolonifer, and Phytophthora palmivora were isolated from infected papaya fruits and inoculated onto potato dextrose agar (PDA). The pure cultures were studied using a light microscope and identified based on cultural and morphological features. For in vitro assay, the PDA was amended with different concentrations of moringa leaf and seed aqueous extract (MLWE and MSWE) and moringa leaf and seed ethanolic extract (MLEE and MSEE) at concentrations of 10, 20 and 30%. After seven days of inoculation, the mycelium growth of the fungi was recorded. Treatments MLEE and MSEE suppressed mycelium growth of the studied pathogens by 100%. While, MLWE was most effective at a concentration of 30% for P. palmivora and R. stolonifer as it recorded a maximum mycelium growth inhibition of 71.28 and 33.71%, respectively. MSWE was most effective at a concentration of 10% for C. gloeosporioides and P. palmivora as it recorded a maximum mycelium growth inhibition of 28.24 and 57.45%, respectively. Ethanolic-based extracts had higher antifungal activity at all concentrations and were more effective in suppressing mycelium growth of papaya fungal diseases compared to aqueous extracts. Scanning electron microscope images showed that moringa extracts suppressed the mycelium growth of papaya fungal diseases by breaking and shrinking hyphal strands of pathogens as well as by reducing the number of spores. In conclusion, Moringa oleifera extracts can be used as a readily available and environmentally friendly alternative to synthetic chemicals.
Langa, S., Tesfay, S.Z., Mbili, N.C., Magwaza, L.S. and Mditshwa, A. (2021). Effectiveness of different formulations of moringa extracts against postharvest papaya diseases. Acta Hortic. 1306, 347-354
DOI: 10.17660/ActaHortic.2021.1306.45
https://doi.org/10.17660/ActaHortic.2021.1306.45
antifungal activity, Moringa oleifera, mycelium, plant extracts
English
1306_45
347-354

Acta Horticulturae