EFFECT OF DIFFERENT LEVELS OF SOME CHEMICAL PESTICIDES ON THE NUMBER OF NITROGEN-FIXING AND PHOSPHORUSSOLUBILIZING BACTERIA

Abstract

The study included a field survey to detect pesticide residues in soil and plants. This was done by collecting samples of soil from the rhizosphere of three different fields planted with plants (cabbage, orange, cauliflower) from different locations in Diyala Governorate (Abu Sayda, Al-Muqdadiya, Diyala University), treated with a fungicide, insecticide, weedicide, respectively. The samples were collected from the fields at four stages (before adding the pesticide, one month after addition, flowering stage, harvest stage), with three replicates. Pseudomonas, Bacillus, Azospirillium bacteria were isolated and diagnosed, and the residues of the three pesticides were detected in soil and plants. In addition, a laboratory experiment was conducted to study the effect of four different levels of pesticides on the number of two isolates of each bacterium (an isolate isolated from the pre-treatment stage and an isolate treated with the pesticide) in solid industrial media.