Effect of monocrotophos and quinalphos on soil population and nitrogen-fixing activity of Azospirillum sp.
The effects of monocrotophos and quinalphos on population and nitrogen-fixing activity of Azospirillum sp. in four agricultural soils were determined in a laboratory study. Concentrations of the two insecticides up to a 5 kg ha-1 level were either stimulatory or innocuous to the population of Azospirillum in the soils. Four successive applications of the insecticides to soils resulted in a significant increase in the population density. Cultures of Azospirillum sp., isolated from insecticide-treated soils, exhibited greater nitrogen-fixing activity. Three consecutive subculturings of the isolates from insecticide-treated soils had no effect on their nitrogen-fixing activity.
Rangaswamy
V
V
Department of Microbiology, Sri Krishnadevaraya University, Anantapur, India.
Charyulu
P B
PB
Venkateswarlu
K
K
D001419:Bacteria / Q000187:drug effects*; D007306:Insecticides / Q000633:toxicity*; D008999:Monocrotophos / Q000633:toxicity*; D009586:Nitrogen Fixation / Q000187:drug effects*; D009946:Organothiophosphorus Compounds / Q000633:toxicity*; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000633:toxicity*
D007306:Insecticides; D009946:Organothiophosphorus Compounds; D012989:Soil Pollutants; C009145:quinalphos; D008999:Monocrotophos