Population Dynamic of Plant-Parasitic Nematodes and Varietal Susceptibility in Solanaceae and Cucurbitaceae Crops in Yamoussoukro, Central Côte d'Ivoire

Vegetable crops play a significant role in Côte d’Ivoire’s agriculture but face challenges from various pests, including plant-parasitic nematodes. Integrated pest management (IPM), which combines selecting resistant crop varieties and optimizing chemical treatment timing, is one strategy to manage these pests. This study aimed to investigate nematode population dynamic and varietal susceptibility in Solanaceae and Cucurbitaceae crops in Yamoussoukro, Côte d’Ivoire. Eight vegetable crop varieties were planted in a randomized block design under natural conditions over two consecutive years without nematicide application. The tested crops included cucumber (F1 Tokyo and Poinsett+), zucchini (Color and Koubera), bell pepper (Simbad and Yolo Wonder), and tomato (F1 Cobra 26 and Mongal). Observations at flowering and harvest stages provided data on aerial and root symptoms, prevalence, severity, and nematological analysis. These data were subjected to analyses of variance at the 5% significance level. Based on the severity and population density of the nematodes, a hierarchical analysis of principal components (HCPC) was carried out to cluster the different varieties. The main symptoms were root galls, leaf yellowing, wilting, and stunted growth. Five plant parasitic nematode genera were identified: Meloidogyne, Radopholus, Pratylenchus, Helicotylenchus, and Rotylenchulus, with Meloidogyne being dominant, representing 48% and 87% of the nematode populations in cucumber and bell pepper, respectively. The population of Meloidogyne decreased globally from 15,999 individuals per 100 g of root in year one to 5,992 in year two. However, populations increased from the flowering (6,009 individuals/100 g root) to the harvest stage (15,522 individuals/100 g root). F1 Tokyo, Poinsett+, and F1 Cobra 26 varieties were susceptible to root-knot nematode because their severity was greater than 50%. The moderately resistant varieties were Simbad, Yolo Wonder, Color, Koubera and Mongal, with severity levels of between 10-50%. These findings offer valuable insights for growers on varietal selection and treatment timing and support the recommendation of crop rotation, mainly to avoid successive crop plantings from the same family. Additionally, Yolo Wonder, Simbad, Mongal, Poinsett+, and Koubera should be recommended for cultivation in nematode infested areas.