Bactérias de nim no controle do complexo Meloidogyne x Fusarium em bananeira

Abstract

The Panama disease and plant parasitic nematodes are responsible for losses in banana yield. There is evidence that fungicidal and nematicidal effect of neem may be related to epiphytic and endophytic microorganisms associated with plant. Therefore, this work was carried out in order to evaluate: In the first chapter, the effect of bacteria from neem leaves on mobility and mortality of second stage juveniles (J2) of Meloidogyne javanica and on the penetration and reproduction in plantlets of 'Prata-Ana Jand 'Maça' banana; and in the second chapter, the effect of those bacterial isolates on antagonism to Fusarium oxysporum f. sp. cubense (foc), and to evaluate the effect of the same associated with the sterile neem extract (SNE) way on M. javanica and foc, and on M. javanica + foc complex in 'Maça' banana. In the first chapter, it was observed that 57.14% of bacteria from neem promoted more than 50% of mortality of J2 of M. javanica. About 66.66% of the isolates reduced from 72.64% to 97.13% penetration of J2 of M. javanica in 'Prata-Ana' banana roots with synergistic effect between the isolates and the SNE. In the greenhouse, the SNE increased the plantlets length and reduced the number of egg masses. The BNF 7 and BNF 2 isolates in SNE stood out in reducing the number of galls and egg masses. In the second chapter, there was a reduction of up to 35.57% of the mycelial growth of foc in the presence of 45.45% of the evaluated isolates. The fermented neem extract caused lysis of foc microconidia. However, SNE and centrifuged neem extract stimulated germination. The reduction in germination of foc was linear with increasing concentration of bacterial cells to 82.85% of the tested isolates. In the greenhouse, the EPI 6 isolate excelled in promoting growth within the Mj x foc complex. Nevertheless, the BNF 9 isolete was the most promising in reducing the number of eggs, reproductive factors and the severity of the Panama disease within the Mj x foc complex. The association of bacteria from neem with SNE has the potential to control the Mj x foc complex, and researches should be conducted seeking more information on that association.