Using of biological pesticides, either of bacterial or fungi origin, and the addition of organic material to the soil can be an effective alternatives to the environmentally unsafe chemical treatments that are used to control plant parasitic nematodes Therefore, the present study analyzed the suppressive effects of some commercial formulations of biological pesticides, either of bacterial or fungal origin, on the soil populations of the root-knot nematode, Meloidogyne spp., in potato fields. Also, we evaluated the efficacy of the addition of some organic materials to the soil, either alone or combined with biological pesticides on the occurrence of nematode density. Four cultivars of potato were planted during 2016/2017 season.
We hypothesized that the addition of organic materials, either alone or mixed with selected biopesticides, could provide faster and better nematode suppression attacking potato.
The main results of this present study revealed that:
v The survey study showed that there were eight nematode genera associated with potato soils, and Meloidogyne spp. was considered as the most widely distributed genera with the four potato cultivars.
v The' Spunta' cultivar seemed to be the most sensitive to be infested by nematodes.
v The effectiveness of NemaFree ، ®NemaStop ® , Dipel-2X® in reducing the population density of Meloidogyne spp. compared to other treatments, whereas, the conventional nematicide ‘COUNTE®' was still the most effective pesticide.
v The addition of organic materials, vz. Organic compost, biofertilizers Nirobein®, and Phosphorin® into the soil significantly reduced population density of root-knot nematode.
v The nematicidal activity of biological pesticides increased when applied in combinations with certain organic materials. The most effective mixtures were: [Dipel-2X + NemaStop® + Compost] and [NemaStop® + Dipel-2X® + Polutry manure].
v These mixtures, in general, resulted in significant increase in average of plant tuber yield per plant.
v The biological pesticides, NemaStop, NemaFree and Mycorrhizeen, applied alone or in combinations with compost or biofertilizers resulted in significant increase in the levels of Catalase and peroxidase activities in leaf tissues.
v In conclusion, these results revealed that these amendments are thus promising for the control of plant parasitic nematodes in sustainable agricultural systems.