Ability of Some Antagonistic Fungi for Controlling Cucumber Downy Mildew Disease Caused by Pseudoperonospora cubensis

Abstract

The aim of this study is to find an effective alternative method for controlling cucumber downy mildew disease caused by Pseudoperonospora cubensis by using eco-frind by fungi such as Trichoderma viride and Trichoderma harzianum instead of chemical fungicide like copper acrobat under greenhouse conditions. Sprayed method of antagonistic fungi spore suspension was used on plants at a rate of 1 x 107 colony forming unit (cfu). By applying it before any symptoms of infection appear (in a protective method), and ten days after the appearance of symptoms of infection (in a curative method). The results of the obtained experiment here showed that T. harzianum was superior during different growth periods up to 90 days, as it gave 44.30% disease incidence and 19.26% disease severity compared to both control (100% disease incidence as well disease severity) and the chemical fungicide (66.67% disease incidence and 25.93% disease severity). The results of a curative trial also showed T. harzianum was given during different growth periods up to 90 days, where 40% disease incidence and 31% disease severity compared to control (100% disease incidence and disease severity 74.44%) and chemical fungicide (20% disease incidence and 29.49% disease severity). While T. viride achieved moderate results as compared to control (60% disease incidence and 27.22% disease severity).From the results obtained, it is evident that T. harzianum gave better results than T. viride, and therefore we recommend using it in resisting downy mildew in cucumber.