Optimizing Peganum harmala L. and Ricinus communis L. for Sustainable Nematode Control and Growth Stimulation in Melon Cultivation

Root-knot nematode ( Meloidogyne javanica ) is a major pest responsible for significant crop losses globally, particularly affecting melon ( Cucumis melo ). Organic amendments offer an eco-friendly alternative to chemical nematicides for managing plant-parasitic nematodes while enhancing soil health and crop growth. This study evaluated the efficacy of dried powder from Ricinus communis (castor) aerial parts and Peganum harmala (Syrian rue) seeds as bionematicides and biostimulants. Pot experiments were conducted to establish dose-response relationships and determine the effective inhibitory dose (DI90) of these botanicals against M. javanica in melon cultivation. Results showed that P. harmala and R. communis significantly reduced nematode populations at DI90 levels of 0.72% and 1.52%, respectively. In addition to nematode suppression, both treatments enhanced plant growth, with P. harmala showing a superior biostimulant effect. Substrate analysis further indicated improvements in organic matter content and nitrogen availability, especially in P. harmala -treated soils. These findings highlight the potential of P. harmala and R. communis as sustainable alternatives for nematode management, with promising applications in organic and conventional farming systems. Future research should focus on identifying active compounds responsible for the observed effects and further evaluating their field-scale efficacy. Keywords: Bionematicide, Meloidogyne javanica , organic amendments, sustainable agriculture, melon cultivation DOI : 10.7176/JNSR/15-3-03 Publication date : September 30 th 2024