Potencial de bactérias isoladas de raízes de figueira e folhelhos pirobetuminosos no controle de Meloidogyne incognita em Ficus carica cv. Roxo de Valinhos ; Potential of bacterial isolated from the roots of fig and pirobetuminoso shales in the control of Meloidogyne incognita in Ficus carica cv. Roxo de Valinhos

The fig tree (Ficus carica L.) is a fruitfull grown throughout the world due to its ability to climate adaptation; being important economically to Brazil and Rio Grande do Sul State in the family farming context. However, pests such as the root-knot nematode Meloidogyne incognita seriously affect the fruit production considering the high aggressiveness of this nematode and the lack of effective management technologies for control of this pest. In this context, the phytosanitary management in infested fig orchards by this nematode is essential to allow the economic viability for this fruit crop. Thereby, the introduction of biological control in the M. incognita integrated management is an important strategy. Among biocontrol agents, the rhizobacteria are good rhizosphere competent bacteria for promoting plant growth and or inhibiting the action of parasitic nematodes on host plants. Therefore, the objectives of this study were: 1) To isolate bacteria with potential for biocontrol of M. incognita from the fig tree roots and pirobetuminoso shale rocks; 2) to characterize the most promising isolates through biochemical tests and DNA sequencing; 3) to evaluate the performance of selected bacterial isolates in the biocontrol of M. incognita on fig tree growing in naturally infested soil under two application forms of the microorganisms; and 4) to evaluate the effect of treatments on bacterial inhabitant nematofauna soil. Firstly, the bacterial isolates obtained from the pirobetuminoso shales and from the fig roots were evaluated on the hatching and mortality of M. incognita second-stage juveniles in in vitro tests besides the production of related compounds to biological control of nematodes. Fourteen bacterial isolates produced at least one compound related to the biocontrol of plant parasitic nematodes (protease Litmus milk and gelatin, lipase, chitinase and or ammonia), and high levels of mortality (78-100 %) or inhibition of hatching (73-100 %) of second stage juveniles of the nematode. Subsequently, these ...