Suppression of root rot and damping off diseases of strawberry plants by using biological control

Abstract

The present work aimed to reduce using toxic chemicals in agriculture process to produce high quality food in sufficient quantity and to enhance biodiversity system. In addition, an attempt was tried to find out the most suitable bio agent that has the ability to protect strawberry plants against some soil borne fungal diseases. Several fungi have been reported to attack strawberry roots i.e. Rhizoctonia solani, Fusarium solani, F. oxysporum and Macrophomina phaseolina (Tassi) Goid causing root rot and damping off diseases. These diseases cause economic losses in strawberry and a wide range of other cultivated plants.The most dangerous effects of R. solani occurred due to pre-, post- emergence damping-off and root rot diseases. Isolates of Trichoderma as “Trichoderma harzianum, T. viride, T. hamatum” and commercial preparations “Plant Guard and Blight Stop” were used in this study. All tested antagonists used as suspension 30×106/ml. reduced the incidence of pre- and post-emergence damping off. T. harzianum, T. viride and Plant Guard were the most effective antagonists as shown by the highest plants survival and the best fruits yield under field conditions. Moreover application of these antagonists recorded the highest increase in total phenols, amount of protein and chlorophyll of strawberry in comparison with the control. On the other hand, T. hamatum and Blight Stop showed the lowest effect. This trend was true during the two successive growing seasons 2014 and 2015.