LAUSR

Tomato is one of the most important fruit vegetables for human consumption in Algeria. In recent years, the cultivation of this plant is experiencing a very rapid development. However, this speculation is confronted with several problems including plant health. The purpose of this study is to find biological ways to introduce them into an integrated control program against tomato pests and have an organic agriculture that can increase the production of this culture. Direct confrontation test of an indigenous strain of Trichoderma harzianum with two phytopathogenic fungi that are isolated from tomato leaves (Fusarium oxysporum f. sp. radicis-lycopersici and Alternaria solani) was carried at 26 °C on an artificial culture medium (PDA). It could be demonstrated that T. harzianum inhibited mycelia growth of the two fungi with more than 40% and only after 4 days of incubation. Statistical analysis confirms that T. harzianum had a significant effect of antagonism against the tested pathogens mentioned before with P value 0.02 and 0.04, respectively. Beyond this period, and at the end of the sixth day, T. harzianum occupied the colonies of fungus and began to sporulate marking a very important myco-parasitic power. Indeed, a percent inhibition greater than 50% was recorded into the both fungi.