Evaluation of Some Plant Extracts, EM-1, and Chitosan to Control Fungi Causing Root Rot in Broad Bean Plants

The study aimed to evaluate the efficiency of the microorganism preparation, effective microorganisms (EM-1), the chemical inducer chitosan, and plant extracts to control broad bean root rot pathogens under laboratory conditions. Many species of fungi were isolated and diagnosed from the roots of broad bean plants infected with root rot. The most common pathogenic fungi were Rhizoctonia solani and Macrophomina phaseolina, isolated from all regions. The results showed that microorganism preparation EM1 inhibited the growth of R. solani (Rs4) and M. phaseolina (Mp6) on the potato dextrose agar (PDA) culture medium at 10 and 15% concentration with 100% inhibition compared to the control treatments. Chitosan also inhibited the growth of R. solani and M. phaseolina in the PDA medium; however, treatments with Sinapis alba (Mustard), Plantago spp. (Plantago), and Sinapis arvensis (Charlock) plant extracts were variable under similar conditions. S. alba inhibited the growth of these fungi at 10 and 15%, and 100% inhibition was recorded. The Plantago extract was specifically effective against R. solani. The results of this study are the first in Iraq to demonstrate the effectiveness of the chemical inducer chitosan in inhibiting the growth of the pathogenic fungi that cause the root rot disease of broad beans..