تأثیر قارچ تریکودرما، باکتری باسیلوس و چندین عصاره گیاهی بر فعالیّت نماتد ریشه‏گرهی در شرایط گلخانه

Root-knot nematode species (Meloidogyne spp.) are the most important known plant-parasitic nematodes. This nematode causes damage to crops and reduces their yield. Among the bacteria and fungi effective in biological control of root-knot nematodes, species of Bacillus bacteria (Bacillus spp.) and Purpureocillium fungus produce toxic compounds, and fungi such as Trichoderma also have nematode-eating properties. On the other hand, essential oils and plant extracts derived from different plants such as thyme, cinnamon, and marigold, as a natural and environmentally friendly approach, can effectively reduce the population and reproduction rate of this pathogen. In this study, four biological treatments (with and without nematode) including Trichoderma asperellum, Bacillus spp., marigold flower extract (Topal commercial name), and cinnamon extract 30% + pine extract 65.6% were applied against root-knot nematodes M. javanica species. The initial nematode population was prepared from the infected greenhouse and the nematode species was identified by preparing the perineal pattern of the female nematode. The experiment was conducted in greenhouse conditions and in three-kilogram pots as a completely randomized factorial design with three replications for each treatment. One week before the transfer of tomato seedlings (Sunseed 6189 cultivar), the soil of the pots was infected with 6000 root-knot nematode eggs. Finally, after 60 days of transplantation and completion of the second generation of root-knot nematode, the parameters of reproduction and pathogenicity of the nematode were investigated. Comparison of mean and analysis of variance of data was done based on Tukey's test at 1% level. The results of the experiment showed that the lowest number of galls and egg mass in the whole root was in Trichoderma treatment with a decrease of 38% and 56%, respectively, compared to the control. Also, the lowest number of eggs in the whole root was related to the Bacillus treatment with a 40% decrease compared to the control, followed by the two treatments of cinnamon + pine extract and Trichoderma with a decrease of 29% and 21%, respectively, compared to the control, and all three treatments were not different significantly (P < 0.01). The lowest final nematode population and reproduction factor (Pf/Pi) was related to Bacillus treatment, which was not different significantly (P < 0.01) with cinnamon + pine extract and Trichoderma treatments. The three mentioned treatments reduced the root-knot nematode reproduction factor by 20-40% compared to the control.