EFFECTS OF PESTICIDES ON

ABSTRACT: Studied in this paper were the effects of three concentrations of four different pesticides (two herbicides — Ro-Neet and pyramin, one insecticide — lindan and one fungicide — mankogal) on the growth of pure cultures of three Azotobacter chroococ-cum strains. The lowest and highest concentrations used in the study were ten times lower and ten times higher than the concentration used in actual agricultural practice (in the field), respectively. The pesticides had different effects on the growth of the Azotobacter chroo-coccum strains. All three strains of Azotobacter chroococcum grew unimpeded regardless of the pyramin, Ro-Neet-a and lindan concentration, whereas all three mankogal concentrations caused growth inhibition to occur in the three strains, which can, therefore, be deemed highly susceptible to the fungicide mankogal. KEY WORDS: Azotobacter chroococcum, fungicides, herbicides, insecticide