Nitrogen Fertilization and Rhizobacteria in the Control of Meloidogyne javanica in Common Bean Plants

Abstract

The effects of treating seeds of the common bean with rhizobacteria before sowing associated with different nitrogen (N) doses on the control of the nematode Meloidogyne javanica was evaluated. The assay was carried out in a greenhouse in random blocks, with a factorial arrangement of 5 × 5 + 1: five N doses (0, 25, 50, 100, and 200 kg/ha); five isolates: Bacillus pumilus (1, 60 and 76), Bacillus subtilis.-34, Bacillus sp.-36, and one control treatment. The plants were inoculated with 3,000 nematode eggs/pot. After 60 days the assay was evaluated. In the absence of N, B. pumilus-60 promoted a reduction of more than 50% in the number of galls and egg masses compared to the control. B. pumilus (1 and 76) and Bacillus sp.-36 reduced the number of galls in combination with increased N doses. Treatment of seeds with Bacillus in combination with N fertilization contributed to a reduction in the number of galls and nematode egg masses. B. pumilus (60 and 76) reduced the number of galls and egg masses in the absence of N, indicating a nematicidal effect. The treatments had no effect on the number of second-stage juveniles, eggs, or the plant parameters.

Association of Bacillus subtilis 34 and soil conditioner for promoting growth in okra plants

“…Longer and fine roots, for the same mass (same metabolic consumption), present a larger surface area and, consequently, in a higher capacity to absorb nutrients, mainly those with low mobility in the soil, such as phosphorus. The rhizobacterium evaluated in the present study (B. subtilis-34) has been shown to be efficient in promoting the growth of vegetable, common bean, and banana plants (Lopes et al, 2019a;Lopes et al, 2019b;Santos et al, 2019;Lopes et al, 2018). Most studies found in the literature evaluated rhizobacteria and water-retaining materials separately (Basyony and Abo-Zaid, 2018;Andrade et al, 2023), thus neglecting the potential synergistic effects of the combined use of these agents.…”