SPATIAL DISTRIBUTION OF PHYTOPHTHORA PALMIVORA-MF IN THE ROOT ZONES OF PIPER NIGRUM

Abstract

The spatial distribution of propagules of Phytophthora paimivora MF, In the root zones of both diseased and apparently healthy vines of black pepper Piper nigrum L was investigated. The intensity of fungal population was estimated in soil samples at O. 30. 6(1 and 90 cm distances from the base of the vines and at depths of 0-10,11-20, and 21·30 em 211 ",ac:h of these distances using pepper leaf discs as bails. Based on the number of infected baits, the spots, in the root zones were classified as spots with low and high levels of fungal population. The spots with high levels of population followed a binomial distribution With probabilities (Pi of 0.70 at 0 and 30 em and 0.42 at 60 and 90 cm distances in the root regions of infected plants The study indicated that the fungal population occurred at higher concentrations around the base of the infected plants upto a distance· of 30 cm from the base and in the upper layers of soil and the population decreased with increase in depth and distance.