Occurrence and distribution of Tylenchulus semipenetrans in Andhra Pradesh

Twenty-one genera of plant parasitic nematodes were recorded from the rhizosphere of acidlime and sweet orange trees. Helicotylenchus spp., Pratylenchus spp., Rotylenchulus reniformis, Tylenchorhynchus spp. and Tylenchulus semipenetrans were the pre dominant nematodes recorded. T. semipenetrans recorded the highest absolute frequency, absolute density and prominence value. It was observed that trees of 6–10 years old supported the highest population of citrus nematode. Similarly, “apparently healthy” trees supported more nematode population than declined trees. Maximum population of citrus nematode was recorded in clay soil followed by clay loam, sandy loam and laterite soils.