Environmental Friendly Way to Control Root-Knot Nematodes Meloidogyne Incognita Infecting Grapevines

This study investigated environmentally friendly alternatives to control the root-knot nematode (Meloidogyne incognita) in Thompson seedless grapevines. Three treatments were evaluated over two consecutive growing seasons (2021 and 2022) under field conditions: the bioagent Trichoderma harzianum, jojoba plant oil extracts, and the specific nematicide oxamyl (oxafors(R); 24% SL). The study assessed the impact of these treatments on nematode populations (total population, rate of build-up, numbers of juveniles in soil (J2) (250g), J2 egg-masses and galls in roots), leaf chlorophyll content and N, P and K contents percentages in leaves. Results showed that all treatments significantly reduced the overall population and build-up of root-knot nematodes, M. incognita, in roots and soil, particularly three months - after application. Oxamyl proved most effective in reducing nematode populations and buildup in both soil and roots throughout both seasons, followed by jojoba oil extract where the bioagent (T. harzianm) was the least effective treatment overall. Also, oxamyl was the most effective treatment which significantly affected number of second stage juveniles / 250g in soil, followed by (Jojoba oil) and bioagent (T. harzianm). Conversely, the T. harzianm was the most effective one in reducing the number of egg masses followed by oxamyl and then Jojoba oil. Jojoba oil and oxamyl were superior to T. harzianum in increasing nitrogen and potassium levels. Total chlorophyll was at maximum values when vines treated with jojoba oil but had minimum values with T. harzianum treatment.