Factors influencing the prevalence of the root-lesion nematode, Pratylenchus coffeae on oil palm (Elaeis guineensis Jacq.).

The root-lesion nematode, Pratylenchus coffeae is considered to be one of the economically important nematode pests of oil palm and is widely distributed in South India. Its population fluctuates between samples, trees, months and years. Observations on population fluctuation and standardisation of sampling zone on oil palm during 1994–95, revealed a marked increase in nematode population during June to August. Maximum nematode population was recorded at a distance of 100 cm away from the bole region ofthe palm at a depth of 51–100 cm. Ecological conditions such as rainfall, soil moisture, soil temperature and availability of susceptible roots play important roles in the population build-up. Soil temperature, however, was considered to have a decisive effect.