EFFECTS OF AGRO-CHEMICALS ON GROWTH AND DEVELOPMENT OF EARTHWORM, PENTOSCOLEX CORETHRURUS

摘要

Effects of insecticides, fungicides and herbicides against the earthworm, Pentoscolex corethrurus were tested under laboratory and cage house condition at Dharwad during 2000-01. From the acute toxicity study, it is revealed that the pattern of lethality based on LC50 was cypermethrin > carbaryl > alphamethrin > endosulfan > monocrotophos > atrazine > 2,4-D > carbofuran > chlorpyrifos > triazophos > glyphosate > gramaxone > Indofil (mancozeb) > captan > Ridomil (mancozeb+metalaxyl) > NSKE, whereas chronic study indicated that fungicides were less toxic followed b,y herbicides and insecticides. Among insecticides, chlorpyrifos was found to be the safest one as it recorded maximum weight (1463 mg), survivality (80.1%) and cocoons per worm (68) compared to other insecticides. But carbaryl, carbofuran and endosulfan were highly toxic insecticides to P. corethrurus.