Abstract
This study was conducted in the laboratories of the Plant Protection Department/College of Agriculture/University of Basra between 2016 and 2017.The aim of this study was to evaluate the efficiency of Chaetomium globosum and some other saprophytic fungi to control of tomato leaf spot caused by Alternaria alternata. The result of this study showed that C.globosum, Aspergillus niger, and Penicillium spp had a high antagonistic activity against the pathogenic fungus A.alternata in dual culture plates. The results of the plastic house experiment showed that disease severity was decreased in tomato plants treated with bio-agent as disease severity run to 21.66% compared to 45% in control treatment (plants treated with A.alternata). Disease severity in other treatments ranged between 23.2-27 %. Infection rate(r)ranged between 0.07-0.09 in bioagent treatment compared to 0.1 in control treatment. It is also showed that C.globosum had a positive effect on plant yield as it reached 332.3g/plant compared to 154.4 g/plant in control treatment.