Studies on the Occurrence and Distribution of Plant-Parasitic Nematodes in Some Pineapple-Producing States in Nigeria
Nematode pests of pineapple have not been widely studied in Nigeria compared to other countries. This study investigated the geographical distribution of nematodes associated with pineapple in three pineapple-producing states in Nigeria. A total of 78 farms were sampled from Oyo, Ogun and Osun States using the Agricultural Development Project in each state as a pilot to locate representative farmlands in the States. The modified Baermann Extraction Tray method of Whitehead and Hemming was used for the extraction of vermiform nematodes from soil. Eighteen species of plant-parasitic nematodes (PPN) were found associated with pineapple from the fields surveyed as follows: Meloidogyne incognita, Rotylenchulus reniformis, Pratylenchus brachyurus, Tylenchus sp., Helicotylenchus dihystera, Scutellonema brachyurum, Hoplolaimus pararobustus, Criconemoides limitaneum, Paratylenchus minutus, Gracilaria sp., Hemicriconemoides sp., Hemicycliophora sp., Aphelenchus sp., Aphelenchoides sp., Tylenchorhynchus sp., Paratrophurus sp., Dolichoderus sp. and Xiphinema nigeriense. The most prominent plant-parasitic nematodes found in association with pineapple on all the fields were P. brachyurus, H. dihystera, S. brachyurum, R. reniformis and M. incognita occurring at frequency ratings of 88, 80, 71, 56 and 44%, respectively. The study indicated a widespread distribution of plant-parasitic nematodes of pineapple in Southwestern Nigeria.