Plant-parasitic nematodes associated with Citrus aurantiifolia (Christm.) Swingle and their relationship with soil type

Plant-parasitic nematodes (PPNs) pose a significant challenge to citrus farming worldwide, but their distribution and impact in the Al-Ahsa Oasis, Saudi Arabia (KSA), remain poorly understood. This study investigates the prevalence, diversity, and ecological dynamics of PPNs associated with Hasawi Lumi (Citrus aurantiifolia) trees, a key crop in the region. During the summer of 2024, a survey was performed in ten major Hasawi Lumi-growing areas, with 250 soil and root samples collected. Four genera of PPNs were identified, with Tylenchulus semipenetrans (52%), Helicotylenchus (44.8%), Pratylenchus (42.8%), and Xiphinema (22%) being the most prevalent. The physicochemical properties of the soil (e.g., texture, pH, and minerals) were determined to assess their impact on nematode populations. Our results revealed that soil characteristics significantly affect the distribution of PPNs, with sandy soils and moderate organic matter favoring nematode diversity, while high salinity suppresses it. The current research constitutes the initial attempt to assess PPNs in Hasawi Lumi orchards and offers important recommendations that can be implemented to improve citrus fruit yield in Al-Ahsa Oasis. These results indicate that soil factors must be considered in any attempt to manage nematode infection, reflecting the necessity for adopting strategies to improve the productivity of citrus crops in the concerned area.