Fresh carrots purchased from a supermarket were washed with detergent and water, soaked for 15 minutes in a 1.9 (v/v) household bleach/distilled water solution and rinsed with sterile water. The carrots were cut into 1 inch long hemicylinders and placed flat surface down in sterile petri dishes containing a wet filter paper (3 pieces per , randomized). The sample to be assayed was dissolved in sterile water and pipetted onto the upper curved surface of the carrots. ...