Plant Pathology Laboratory, Department of Plant Protection, Palli Siksha Bhavana (Institute of Agriculture), Visva-Bharati, Sriniketan-731 236, West Bengal, India.
A two year intensive survey in 138 plantation farms indicated the presence of Helicotylenchlls dihystera, Scutellonema brachyurum, Pratylenchus coffeae, Criconemella (= Macroposthonia) ornata and C. xenoplax as the most serious populations alongwith 20 other plant parasitic nematodes associated with pineapple in the terai plains and the foot-hilIs of West Bengal (around Siliguri covering three districts and two agro-ecological regions). From the community analysis, S. brachyurum, H. dihystera and C. ornata took first three positions in importance value amongst 13 species of probable pathogenic importance. Cluster analysis, dendrogram and similarity index, computed for major horticultural crops in the region indicated that the nemic faunae were more than 90 per cent identical in Siliguri and Mohitnagar, suggesting that location effects, due to variations in climate cropping system and management practices were minimum in most of the pineapple belt. A system of pathogenic significance ranking has been proposed.
Population ecology, community analysis, cluster analysis, dendrogram, similarity index, pathogenic significance ranking, vertical distribution, pineapple, Helicotylenchus dihystera, Scutellonema brachyurum, Criconemella ornata, C. xenoplax, Meloidogyne spp., Pratylenchlls coffeae
