Streptomyces ssp. e resíduo de sisal no crescimento do tomateiro e controle de Meloidogyne javanica

Abstract

Tomato is amongst the most consumed vegetable crops worldwide, and is susceptible to the infection by nematodes of the genus Meloidogyne, which cause significant yield losses. Non-chemical management strategies such as biological and cultural control have high potential to control plant parasitic nematodes. This study aimed to evaluate the potential of isolates of Streptomyces spp. and residues from sisal leaf decortication process for growth promotion of tomato plants and control of Meloidogyne javanica. Ten isolates of Streptomyces spp. were evaluated for their efficiency for controlling M. javanica in tomato plants grown under green house conditions, in soil with and without cattle manure. In addition, the liquid residue (fresh and fermented), the solid dry and powdered residue and the aqueous extract of this residue were tested for control of M. incognita under in vitro and greenhouse conditions. The selectivity effect of the sisal liquid residue on beneficial microorganisms was evaluated through in vitro assays. Soil enrichment with Streptomyces sp. (isolate BFT 102) caused a reduction of up to 87% in the number of galls and of 97% in egg masssas per gram of tomato roots, in soil without cattle manure. Isolates BFT 7 and BFT 71 caused a reduction of 54% and 65%, respectively, in both the number of galls and egg masses per gram of roots, in the soil with manure. The aqueous extract and the ground powdered solid dry residue, the liquid residues fresh and fermented had nematicide effect with reductions of 37%, 41%, 63% and 67% in the number of galls and 39%, 39%,bb 95% to 97% in the number of eggs per gram of roots, respectively. The fermented liquid residue inhibited growth of beneficial soil microorganisms.