The Effect of Some Medicinal Plant Extracts on Fusarium oxysporum f.sp. lycopersici Causal Agent of Tomato Wilts Disease in Laboratory and Greenhouse Conditions

Fusarium oxysporum f.sp. lycopersici is an important disease agent of tomato which causes wilt and seedling. The present study was performed to evaluate the antifungal effect of Achillea millefolium, Salvia verticillata and Ziziphora clinopodioides extracts and their abilities to inhibit the fungus. For this, methanol extracts of reference plants was extracted and tested in concentrations ranging from ۱ , ۱.۵ and ۲ mg/ml on mycelial growth of Fusarium oxysporum. The same extracts were then tested for antifungal activity in vivo in the greenhouse on inoculated tomato plants. Z. clinopodioides demonstrated highest antifungal activity against mycelial growth of F. oxysporum strain that recorded ۷۷.۱%, ۶۲.۰۳% and ۶۱.۹۹% at ۲, ۱.۵ and ۱ (mg/ml), respectively. the MIC value for of Z. clinopodioides against F. oxysporum was ۳.۱۲۵ mg/ml followed A. millefolium and S. verticillata extract having ۶.۲۵ mg/ml. The MFC of extracts was found to be ۶.۲۵ mg/ml in Z. clinopodioides and ۱۲.۵ mg/ml for A. millefolium and S. verticillate. In greenhouse experiment employing methanol extracts of three plant species showed an increase in the mean plant height and also fresh and dry weight of root and shoot with the consequent reduction in the disease symptoms of the tomato seedlings. Overall, the results showed significant growth inhibition activity of Z. clinopodioides methanol extract against F. oxysporum in both in vitro and greenhouse condition. Although the extracts of A. millefolium and S. verticillata which had no effect in vitro assays, in greenhouse conditions, these plants showed considerable antifungal activity.

Keywords:

Biological control , Disease management , Fungal growth , F. oxysporum , Medicinal plant