Nematodes associated with the lychee crop (Litchi chinensis) in Oaxaca, Mexico

The objective of this research was to determine the main genera of nematodes associated with lychee adult plants and their association with the symptom of chlorosis. To do this, from March to August 2013, soil samples were collected from four commercial lychee plots in the tree drip zone. Five asymptomatic and five plants with chlorosis of the Brewster and Mauritius varieties were selected in three phenological stages: flowering, harvesting and vegetative development. Aphelenchus , Ditylenchus , Helicotylenchus , Hemicriconemoides , Longidorus , Mesocriconema , Pratylenchus , Psilenchus , Rotylenchus , Trichodorus , Tylenchorhynchus , Tylenchus and Xiphinema were the main genera identified. The highest number of total nematodes in Mauritius variety was obtained in the harvest stage (300.6, p=0.05), while in Brewster was in flowering (576, p=0.05). A direct relationship between the total population of nematodes and the symptom of chlorosis was not observed for the different phenological stages evaluated.