NEMATICIDAL ACTIVITY OF WASTE FROM THE PISTACHIO PRODUCTION PROCESS

MANRIQUE, SOFIA; PIÑEIRO, M.; BRIDGE, M; LUNA, L; FERESIN, G.

Congreso; XLI Reunión Anual de la Sociedad de Biología de Cuyo; 2023

Plant-parasitic nematodes (PPN) reduce attainable crop yields and harvest products quality. PPN induced root dysfunction, because affect translocation trough xylem. The Meloidogyne genus is widely distributed worldwide and around 5500 plants are hosts. Synthetic nematicides are the most used method to control PPN, but result in negative consequences as environmental contamination, phenomenon of resistance and a very high cost. Growing concern for the environment and the recent ban of many synthetic nematicides, has led to development alternatives as the use of bionematicides of plant origin. Based on the above, the objective of the present work was to evaluate the nematicidal activity against the root-knot nematode Meloidogyne incognita of natural extracts obtained from pistachio residues (Pistacia vera L.). Exocarp and mesocarp of P. vera (green shell) and endocarp (dry shell) were macerated with water and ethanol:water (1:1), assisted with ultrasound (60 min). Four extracts were obtained: aqueous dry shell extract (ADSE), ethanol:water dry shell extract (EWDSE), aqueous green shell extract (AGSE) and ethanol:water green shell extract (EWGSE). All extracts were evaluated at 10 and 1% v/v for 24 h, as nematicides in vitro against M. incognita (second stage J2). The negative control was water (C-) and the positive control was abamectin (C+Ab). Additionally, the phytotoxicity of the extracts (10% v/v) was analyzed in Allium cepa and Solanum lycopersicum seeds. The extract with the highest nematicidal activity was ADSE10%, it did not show significant differences with C+Ab, for both treatments the mortality percentage was approximately 92%. For AGSE, both concentrations showed moderate activity (~62%). Finally, the rest of the extracts (EWGSE 1%, EWDSE 10%, EWDSE 1% and ADSE1%) presented low nematicidal activity (~16% mortality). The ADSE did not present phytotoxicity in both species, with germination index similar to the controls and tolerance index greater than 65%. In conclusion, ADSE was the best treatment to control J2 of M. incognita and did not affect germination or root growth in A. cepa and S. lycopersicum. This work provides novel results that are aimed at solving four current problems, both local and global: (1) using and revaluing the byproducts of pistachio production, (2) applying eco-friendly techniques, (3) controlled root-knot nematodes and thus (4) reducing the use of synthetic nematicides that are harmful to ecosystem and human health.