Determination of the treatment period of banana seedlings with rhizobacteria in the control of Meloidogyne javanica

Abstract

The introduction of rhizobacteria to the soil can be done via treatment of propagating materials. The aim of this work was to evaluate in greenhouse the influence of immersion periods of micropropagated ‘Prata-Anã’ banana seedling roots in suspension of different rhizobacterial isolates on the growth of seedlings and control of Meloidogyne javanica. The experiment was set up in greenhouse in a randomized block design in a 10 x 2 factorial scheme (rhizobacteria isolates) x (immersion periods: 60 and 120 minutes) with 10 replicates. The additional treatment (control) was composed of seedlings without any treatment infected with M. javanica. Treated seedlings were planted in pots containing soil: previously autoclaved sand. After twenty-four hours, suspension containing 3,000 M. javanica eggs was added to the soil. At 60 days, number of galls, egg mass and eggs per root system, number of second-stage juveniles (J2) per 100 cm3 of soil were evaluated and the reproduction factor was calculated. Shoot dry matter mass was also evaluated. Of the four rhizobacteria that reduced the reproductive capacity of the nematode, three were more efficient when seedlings were treated for 120 minutes. The treatment period of banana seedlings did not affect the shoot dry matter yield and all rhizobacteria increased the dry matter weight of seedlings infected with Meloidogyne javanica. It could be concluded that rhizobacteria have different treatment time requirements for seedlings to control the nematode, but do not interfere with the development of seedlings.