Antifungal activity of essential oils and homemade fungicides against Passalora Fulva

Abstract

Passalora fulva is a pathogen which causes the disease on tomato known as the tomato leaf mold. In the greenhouses, this disease causes big problems during the fall, in early winter and spring, due to the high relative humidity of air and the temperature. The development of the disease is quick, moving from lower to upper leaves so the controlling must be done as soon as possible. The antifungal activity of medicinal plants bioactive compounds has gained a lot of attention within the scientific community. The main factor is the growing problem of multidrug resistance among pathogenic fungi. In addition, medicinal plant oils are the promising sources of antifungal drugs. Based on these facts, the present study emphasizes the importance of plants EOs as an alternative against pathogenic fungi causing tomato leaf mould. The spread of pesticide resistant pathogens is one of the most severe threats to successful treatment of microbial diseases. Renewed recent interest towards EOs utilization has been attributed to several factors, including a general revival in the appeal of ‘natural’ products, the desire for antimicrobial compounds with considerably better safety and toxicity profiles, and more importantly, the need for alternative ways to conventional antimicrobial, since they show reduced susceptibility to many major pathogens. In this paper we have analyzed possible substitutes to synthetic pesticides in controlling the fungus. Since the potential of essential oils (EOs) as antimicrobial agents is well established and farmers around the world already use traditional recipes, we have decided to test a fair amount of essential oils and homemade fungicides against the growth of Passalora fulva mycelium. We have discovered cloves EO kills the fungus at any tested concentration. The next EOs with strong effects are cinnamon, lemongrass, palmarosa, oregano and oil grass. The rest of EOs have shown a medium inhibitory effect.