title: Activities of cellulase and amylase in soils as influenced by insecticide interactions.
abstract: Interaction effects of the insecticides monocrotophos and quinalphos (organophosphates), and cypermethrin (pyrethroid), on microbial activities in two agricultural soils-black vertisol soil and red alfinsol soil were tested for 30 days under laboratory conditions. Individual application of the three insecticides at 5, 10 and 25microg g(-1) to the soil distinctly enhanced the activities of cellulase and amylase. Insecticide combinations involving monocrotophos or quinalphos with cypermethrin yielded synergistic, antagonistic and additive interaction effects on both enzymes in the soils. At lower levels, 5 and 10microg g(-1), the insecticides in combination interacted additively or synergistically toward both enzymes. But, both combinations at the highest level of 25microg g(-1) exhibited an antagonistic interaction, with a reduction in enzyme activities to a level lower than that of the control. Interaction effects of insecticides in combinations on two enzyme activities in both soils were related to populations of cellulolytic and amylolytic organisms in soils under the impact of combination of insecticides. These interaction responses were persistent even for 30 days.
authors.affiliation: Department of Microbiology, Sri Krishnadevaraya University, Anantapur 515 003, Andhra Pradesh, India.
authors.forename: Vijay A K B
authors.initials: VA
authors.lastname: Gundi
authors.forename: Buddolla
authors.initials: B
authors.lastname: Viswanath
authors.forename: M Subhosh
authors.initials: MS
authors.lastname: Chandra
authors.forename: V Narahari
authors.initials: VN
authors.lastname: Kumar
authors.forename: B Rajasekhar
authors.initials: BR
authors.lastname: Reddy
mesh_terms: D000681:Amylases / Q000378:metabolism*; D001419:Bacteria / Q000187:drug effects* / Q000201:enzymology; D001426:Bacterial Proteins / Q000378:metabolism*; D002480:Cellulase / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation; D004347:Drug Interactions; D007306:Insecticides / Q000633:toxicity*; D008999:Monocrotophos / Q000633:toxicity; D009946:Organothiophosphorus Compounds / Q000633:toxicity; D011722:Pyrethrins / Q000633:toxicity; D012987:Soil / Q000032:analysis; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000633:toxicity*; D013997:Time Factors; D015854:Up-Regulation
chemical_list: D001426:Bacterial Proteins; D007306:Insecticides; D009946:Organothiophosphorus Compounds; D011722:Pyrethrins; D012987:Soil; D012989:Soil Pollutants; C017160:cypermethrin; C009145:quinalphos; D008999:Monocrotophos; D000681:Amylases; D002480:Cellulase