Potentials of compost, compost tea and aqueous neem leaves extract in reducing some diseased plants and boosting onion (Allium cepa L.) production in the field at Gapring-Lara in t he Department of Mayo Kani (Cameroon)

With a view to promoting the onion sector, we studied the behavior of onion following the application in fields of Cow Dung compost, compost tea and the aqueous extract of neem leaves during the 2018/2019 and 2019/2020 growing seasons. The device used was a complete randomized block comprising 10 treatments including compost (Cp), compost tea (CpT), Neem extract (Nex), compost + compost tea (Cp+CpT),compost+Neem extract (Cp+Nex), compost tea+Neem extract (CpT+Nex), compost+Compost Tea+NeemExtract (Cp+CpT+Nex), Control (Ctrl), Chemical Pesticide (ChP) and Chemical Fertilizer (ChF) with 3 repetitions each. The work focused on agronomic and phytopathological parameters. The results reveal that Cp+CpT+Nex treatment had a highly significant influence on the germination rate (92.33%) than Ctrl treatment (44%). He was significantly increased the number of leaves, size and yield compared to other treatments with 22.16 leaves, 52 cm and 114.74 t/ha (2018/2019) and 20.83 leaves and 53.84 cm; but yield was higher by ChF with 47.49 t/ha (2019/2020). Nex, Cp+Nex and CpT+Nex treatments reduced attack of Delia antiqua compared to control. And significant reduction in number of plants attacked by onion mildew was observed in Cp+CpT+Nex treatment. In view of the results obtained, organics fertilizers can be used in onion production.