Control of Meloidogyne javanica with Pleurotus djamor spent mushroom substrate

Abstract

Abstract Background The interest in the development of ecologically correct products associated with the loss of efficiency of chemical nematicides for the control management of this pest is growing. Thus, the adoption of biological control or the use of biopesticides are excellent options for these products. Spent mushroom substrate (SMS), a product of the mushroom production industry, has great potential for biological control due to its high levels of mycelium, residual enzymes, high humidity and unique microbiota that may contain other nematode antagonists. For this reason, this study aimed to evaluate the potential of spent mushroom substrate (SMS) from Pleurotus djamor cultivation in the control of Meloidogyne javanica in lettuce and assess its effects on plant resistance enzymes and soil biological activity. Results SMS reduced nematode reproduction, and a plateau was reached at SMS concentrations above 15%. Higher concentrations of SMS caused phytotoxicity in lettuce, with reduction of vegetative variables, chlorophyll content and nitrogen balance in the leaves; however, SMS increases the anthocyanin content. Guaiacol peroxidase activity was highest in treatments containing 0% and 30% SMS and phenylalanine ammonia-lyase activity was highest in the 60% SMS treatment, suggesting induction of resistance to M. javanica. The maximum soil basal respiration was estimated to be achieved with 25.75% SMS, whereas the maximum soil metabolic quotient was estimated to be achieved with 8.8% SMS. Soil biomass carbon increased with increasing SMS proportion. Conclusions Spent substrate from P. djamor cultivation incorporated in soil at proportions of 15, 30, 45 e 60% is efficient in controlling M. javanica in lettuce.