Non-toxic Washing Solutions for Decreasing Myclobutanil, Fenhexamid and Boscalid Residues in Sweet Pepper and Cherry Tomatoes

Four aqueous solutions of 5% sodium carbonate, 5% sodium hypochlorite, 5% glycerol, 5% acetic acid in addition to tap water were evaluated for their removal efficiency of myclobutanil, fenhexamid, boscalid residues from sweet pepper and cherry tomato. The tested crops were treated with the recommended rate of application of myclobutanil, fenhexamid and boscalid. The initial residues of the investigated pesticides before washing treatments in pepper samples were higher than in tomato samples. The tested washing solutions showed similar behaviour in both crops, but the efficiency was slightly different due to the different initial concentration. Tap water was the most effective treatment in reducing myclobutanil residues in pepper and tomato samples but with no significant difference with sodium carbonate, sodium hypochlorite and acetic acid. For fenhexamid, tap water treatment was significantly more efficient in reducing its residues than the other tested washing solutions. The reduction percents of fenhexamid residues by sodium carbonate, sodium hypochlorite and acetic acid were insignificantly different in both crops. Glycerol treatment was significantly the least effective treatment in removal of myclobutanil and fenhexamid residues in both crops. Despite of the seemingly higher efficiency of tap water treatment in removing boscalid residues, statistical analysis showed that there were no significant differences between all tested washing solutions in both crops. The residues of the investigated pesticides after pesticide treatments in both crops were generally higher than the MRL but the tested washing solutions showed significant efficiency in removing the residues to be below than the MRL in most cases