Abstract
Ninety six soil and root samples taken from 48 tobacco fields in central Trinidad were analysed for plant parasitic nematodes. The results showed qualitative and quantitative differences in the nematode populations according to soil texture and previous crops planted. The total number of nematodes per 200 ml of soil or per 10 g root sample ranged from 711 to 9143 with an overall mean of 3532. The most prevalent plant nematodes were Aphelenchus avenae; Helicotylenchus erythrinae; Meloidogyne incogmta; Pratylenchus penetrans; Tylenchus spp. and Tylenchorhynchus spp. Population densities of Pratylenchus and Meloidogyne were considerably higher and were usually associated with low tobacco yield.