The following study aimed to isolate some pathogenic fungi from cowpea (Vigna unguiculata L.) plants infected with root rot disease and determine their tenacity to pathogens using some plant resistance induction factors and the biological fungus Trichoderma spp. The results showed the presence of cowpea root rot disease in all areas included in the survey in the Babylon Governorate. The 13 types of fungi accompanied the roots of the cowpea plant. Fusarium solani was the most abundant pathogenic fungus, with a frequency rate of 55.9%, followed by the fungus Macrophomina phaseolina, with an appearance rate of 45.55%. Isolates of the fungus Trichoderma spp. (T. viride, T. harzianum, T. koningiopsis, and T. reesei) achieved a high antagonistic ability against pathogenic fungi under laboratory conditions. The highest antagonistic ability was one for the T. viride isolate against the pathogenic fungi F. solani and M. phaseolina. The results revealed that adding chitosan to the culture medium at all concentrations led to growth inhibition of the fungi F. solani and M. phaseolina compared to the inhibition percentage of 0.00% in the control treatment.
Cowpea (V. unguiculata L.), Trichoderma spp., chitosan, fungi, root rot diseases
The emergence of cowpea (V. unguiculata L.) root rot disease caused by pathogenic fungi prevailed in contaminated soils of the Babylon Governorate, Iraq. The results revealed the effectiveness of the biological agent Trichoderma spp. against pathogens. The chemical inducer chitosan proved to inhibit and eliminate the two pathogenic fungi, F. solani and M. phaseolina.