Investigating the effect of different aqueous and alcoholic extracts of some medicinal plants on the growth of apple blue mold (Penicillium expansum)

Post-harvest diseases are one of the most common causes of damage to fruits and vegetables, and the use chemical fungicides is the fastest method to control it. Therefore, in this study, it was investigated the effect of Neem, Thyme, fennel and Zataria extracts on apple blue mold, as an alternative to chemical fungicides. In this study, it was studied the effect of the plant extracts in vitro on the growth of fungal pathogen apple blue mold (P. expansum) by two methods included the paper disks and mixed media culture. Then, the effect of some plant extracts of Thyme and Fennel was studied on the rate of symptoms in a cold storage (4 ̊C). The results showed that the aqueous and alcoholic extracts of thyme with a concentration of 500 ppm and with 24.79 and 26.65 mm diameter inhibition zone of pathogen, respectively, were the best extract. The results of another in vitro test, the mixing test of plant extracts with the culture medium, were exactly the same as the disk test, and the concentration of 2000 ppm of aqueous and alcoholic extracts of thyme was 62.49 and 72.66, respectively, it reduced the pathogen growth when it was compared to the control. The results of the storage test showed that the area of spot formed in the treatment of aqueous and alcoholic extracts of thyme with a concentration of six in 1000 was 70.52 and 85.69% in comparison with the control, in other words, this concentration of thyme aqueous extracts showed the highest control of the disease in the storage. Based on the findings of this study, Thyme and Zataria extracts had the potential to control plant diseases, especially post-harvest diseases