The Effect of Different Rates of Two Pesticides (Benomyl and Abamectin) on Growth and Number of N2 Fixation Bacteria Cells (Azotobacter and Burkholderia spp)

Merfat T. Ben Mahmud*(1) and Eman A. AL Ferjani(1)

(1). Department of Soil and Water, Faculty of Agriculture, Tripoli University, Tripoli, Libya.
(*Corresponding author: Dr. Merfat Ben Mahmoud. Email: dr.mbenmahmoud@yahoo.com).

Received: 04/04/2017                                     Accepted: 08/06/2017

Abstract

A laboratory experiment was carried out with Randomized Completely Block Design (RCBD), to study the effect of two chemical pesticides: fungicide (Benomyl 50%) and Acaro-Insecticide (Abamectin) with three rates for each treatment, on growth and number of Azotobacter and Burkholderia. Three dilution of inculcation bacteria (10-4, 10-5, and 10-6) with four periods of incubation (3, 7, 14, and 21) days were used for measuring (MIC) of bacteria cells number. The results showed that the minimum (MIC) value of Benomyl fungicide with dilution of (10-4) was (1.22 g/L), and (0.5 g/L) for each dilution of (10-5 and 10-6), after twenty-one days of incubation for Azotobacter and Burkholderia. The minimum value of (MIC) for Abamectin insecticide was (0.875 ml/L) for the periods of (7, 14 and 21 days) of incubation with all dilution inoculations of Azotobacter and (14 and 21 days) of incubation for Burkholderia. The results concluded that Benomyl and Abamectin had a different effect on growth and number of the studied bacteria according to their concentrations, and incubation periods. Also Azotobacter and Burkholderia were more tolerance for the dilution of 10-4 of pesticides as compared with other concentrations 10-5,    10-6.

Key wards: Azotobacter, Burkholderia, Benomyl fungicide, Abamectin insecticide.

Full paper in Arabic: The Effect of Different Rates of Two Pesticides (Benomyl and Abamectin) on Growth and Number of N2 Fixation Bacteria Cells (Azotobacter and Burkholderia spp)