Determination of minimum inhibitory concentration from chemical Pesticides on bacteria Azotobacter numbers with period of incubation diffrant .

Abstract

Three Laboratory experiments were carried out with (CRBD ) design, to Study the effect of three chemical pesticides namely; fungicide (benomyl ) ,Insecticide (super atracedein ) and herpicide (grawand ab) with (4) levels for each treatment on A.chroococcum number .Three dilution of inculation bacterial ( 10-4 , 10-5 , 10-6) with four period of Incubation (3, 6, 12 and 18) day were used for measuring (MIC) of bacterial cell number. The results showed that (MIC ) of fungicide with dilution of ( 10- 4) is (1.2 ) g.L-1 and (0.6 )g.L-1 for each dilution of ( 10-5 and 10-6) for (18) day Incubation . The (MIC ) of Insecticide is ( 0.875)ml.L-1 for the period of (6,12 and 18) day Incubation with all dilution Inculation . The (MIC ) of herbicide is (20)ml.L-1 for (6) day Incubation with dilution of 10-4 , 10-5 and (10) ml .L-1 for dilution of 10-6. For the period of Incubation (12,18 ) day the (MIC) is (10 )ml.L-1 for dilution 10-4 and (5) m.L-1 for both dilution of 10-5 and10-6. The results showed that the dilution of 10-4 is considered resistant for concentration of pesticide as compared with 10-5 , 10-6 .