Comparative Effects of Natural and Synthetic Fungicides on the Pink Root Disease of Onion (<i>Allium cepa </i>L.), in Nursery

Abstract

Onion is an important vegetable in Senegal horticulture, where it occupies the first place. However in the greatest areas production like the Gandiolais, in the North of Senegal, Pink root disease caused by a soil born fungus Pyrenochaeta terrestris (Hansen) Gorentz, Walker and Larson affects its productivity especially in nursery. On soil sterilized and inoculated by the fungus, we tested 5 natural fungicides and 2 synthetic fungicides, to measure their effectiveness on the Pink root disease on onion, in nursery. The device used is a split plot with 4 repetitions and 8 treatments. The measured variables are the emergence rates, the survival rates and the infestation rates. Our experimentations have shown that, for the emergence rates, there is no significant difference between thiophanate-methyl (Pelt 44), Carbendazim (Bavistine), Azadirachta indica A. Juss and Carica papaya L. It is the same between C. papaya and Moringa oleifera Lam, between M. oleifera and Cassia alata L. It is also the same between C. alata and Crotolaria retusa L. Regarding the survival rates, there is no significant difference between thiophanate-methyl, Azadirachta indica, Carbendazim, C. papaya and M. oleifera. The same is true between M. oleifera and Cassia alata, and between C. alata and C. retusa. Concerning the infestation rates, apart from the control check, all other treatments show no difference.

Promising Natural Products in Crop Protection and Food Preservation: Basis, Advances, and Future Prospects

“…Translaminar fungicides help in even distribution of fungicides from the upper parts of the plants to the lower parts [36]. Synthetic fungicides such as azoxystrobin, prochloraz, or thirame are mostly employed in crop protection, while examples of natural fungicides include rosemary oil, tea tree oil, and jojoba oil among many others [37][38][39].…”

“…include Azadirachta indica leaf extract [97], peels of Ipomoea batatas Lam [98], Curcuma longa leaves [37], C. papaya leaves [38], and thyme and lemongrass extract [99].…”

“…However, extracts from A. indica and C. papaya leaves were compared well with synthetic fungicides in the inhibition of this fungus disease. erefore, A. indica and C. papaya leaves can be engaged as a cheap, readily available, and environmentally friendly alternative in the antifungal therapy [38].…”

Potentials of Medicinal Plant Extracts as an Alternative to Synthetic Chemicals in Postharvest Protection and Preservation of Horticultural Crops: A Review

“…Studies have shown that some plants produced secondary metabolites, such as essential oils and volatile compounds that can have a biocidal action against postharvest pathogens [49,50]. Commercial products of natural fungicides such as rosemary oil, neem oil, Aloe vera gel (AVG), tea tree oil and jojoba oil, among many others, are now used in crop protection and preservation as fungicides [51][52][53], while commercial natural insecticides include nicotine and pyrethrum, amongst others [54,55]. Medicinal plant extracts could be a useful alternative to synthetic fungicides in the control of rot fungi when handling fruits and vegetables after harvest.…”