Experience in using biological methods to control the number of root-knot nematodes Meloidogyne spp. (Tylenchida: Meloidogyniedae) in the greenhouses of the Botanical Garden of Peter the Great

The effect of biological preparations on the development of root-knot nematodes (Meloidogyne spp.) in flower and ornamental plants was investigated in the greenhouse complex of the Botanical Garden of Peter the Great in 2015–2020. A nematicidal effect was noted after soil treatment with crushed aboveground organs of Brassica oleracea L., Nerium oleander L., Sinapis alba L., Tagetes sp. A decrease in the intensity of root system damage and disease spread was noted with prolonged use of solutions of neem oil, Dioscorea powder, chitosan lactate. The use of biological substances is recommended as a preventive method for controlling of root-knot nematodes in greenhouse conditions.