Control of Camellia plant extracts and its preparation against plant parasitic nematodes
For the aim of screening nematicidal materials,Bursaphelenchus xyluplilus and Meloidogyne incognita were used as target in vitro bioassay to determined nematicidal activity of oil-tea cake and other plant materials;further control effects of tea-saponin preparations and oil-tea cake were assessed against root-knot nematode disease in pot experiment and field experiment,respectively.The results showed that plant extracts of oil-tea cake,tea-pericarp,and tea-seed reached strong nematocidal activity,inducing 90,100 and 100% mortality of B.xyluplilus respectively at 10 mg/ml after exposure for 72 h.Plant extracts of oil-tea cake and tea-seed reached medium-strong activity against M.incognita after exposure for 48 h.The effects of plant extracts concentrations on toxicity against B.xyluplilus were observed.The tea-saponin preparations obviously controlled tomato root-knot nematode disease in pot experiment,root gall,and M.incognita juvenile 2(J2) population were reduced;tomato biomass were increased obviously at 30 d after pot-soil treated with 1.5 g and 0.75 g(effective content) tea saponin per 1 kg soil at tomato seedling transplant.Oil-tea cake showed certain effect against root-knot nematode disease in field experiment applied by furrow application one week before Fructus Trichosanthis emergence,and the proliferation of J2 in soil was inhibited significantly 150 d later,while the fruit number and diameter were increased 180 d later after application.This paper reported the pot and field control effects of oil-tea vice products against plant nematodes for the first time.The results provide a basis for directly using oil tea and tea vice-products to the control of crop root-nematode disease.