Plant Pathology and Nematology Laboratory, Department of Plant Protection Palli-Siksha Bhavana (Institute of Agriculture) Visva-Bharati, Sriniketan-731 236.
In mandarin orange decline affected homestead orchards, Tylenchulus semipenetrans (Ts.) and Helicotylenchus dihystera (Hd) were predated upon by Iotonchus tenuicaudatus (It) under normal agricultural practices. True predator-prey relation existed between Ts and Hdwith It.. Rs was the most important parasite and Hd population was low throughout. Winter mulching was most effective against the parasitic nematodes as confirmed by the most stable and greatest abundance in population of It. When forest litter mulch was compared with farmyard manure, NPK, and carbofuran, it was found that carbofuran was most effective in bringing down the population of both parasitic and predator populations. Carbofuran plus FYM plus NPK resulted in best yield in the succeeding year. Forest litter followed by FYM followed by NPK and their combinations could be recommended for orchards with low and moderate populations of Ts Carbofuran plus FYM of forest litter plus NPK was recommended only when Ts populations were at their highest usually once in 5–6 years in unamended soils.
Mandarin orange, predatory nematode, biocontrol, Tylenchulus semipenetrans, Helicotylenchus dihystera, Iotonchus tenuicaudatus, forest litter, organic amendment, conservation of natural enemies/antagonists
