PARASITIC NEMATODES ASSOCIATED WITH CASSAVA (MANIHOT ESCULENTA) GROWN IN AKWUKABI ETCHE, RIVERS STATE.

ABSTRACT This study examined the parasitic nematodes associated with cassava (Manihot esculenta) grown in Etche, Rivers State. A total of 15 cassava plants were randomly selected across different farms in Akwukabi. From each plant, three types of samples were collected: Roots (15 samples), Stems (15 samples), and Rhizospheric soil (15 samples) which gave a total of 45 samples. Healthy and moderately diseased roots (200–300g each) were dug up and collected in sterile polyethylene bags. Sections of stem (about 10 cm length from the basal part) were cut with sterilized secateurs and stored in labeled plastic bags. Approximately 200g of rhizospheric soil was collected at 10–15cm depth close to the cassava roots using a sterile soil auger. Samples were labeled and transported in cooled containers to Biology Research Laboratory, Ignatius Ajuru University of Education for nematode examination. From the result of this study, Out of the 45 cassava samples examined, a total of 34 were positive for plant parasitic nematodes, representing an overall prevalence of 75.6%. Among the different sample types, cassava roots recorded the highest level of infestation, with 13 out of 15 roots (86.7%). This was followed by the soil samples, where 12 of 15 samples (80.0%) were positive. The stem samples had the lowest prevalence, with 9 of 15 (60.0%) testing positive. Four genera were identified. Among them, Meloidogyne spp. were the most prevalent, (41.2%), Pratylenchus spp. followed (26.5%), while Helicotylenchus and Rotylenchulus spp. were comparatively less frequent, accounting for 17.6% and 14.7% of the total isolates, respectively. Risk factor assessment revealed that cultural practices strongly favor nematode proliferation. Continuous cassava monocropping by farmers creates a stable habitat for nematodes, while low adoption of soil fertility management further exacerbates plant susceptibility. Weed infestation of farms, may serve as alternative nematode hosts, sustaining their populations even in the absence of cassava. Therefore, this study has demonstrated that cassava cultivated in Akwukabi Etche is heavily infested with parasitic nematodes, with an overall prevalence of 75.6%. The infestation is most severe in cassava roots, with Meloidogyne spp. emerging as the dominant genus. The study recommends to: Adopt Crop Rotation and Intercropping, Use of Resistant and Improved Varieties, carry out Proper Soil Fertility Management and weed control, Use Integrated Nematode Management (INM), and conduct Further Research Studies on the economic impact of nematode infestation on cassava yield in Akwukabi Etche.