ارزیابی عملکرد ترکیب جدید فرمایسین گلد در مهار بیماری فوزاریومی پژمردگی آوندی گل داوودی

Fusarium vascular wilt disease is one of the important soil-borne diseases of Chrysanthemum flower. In this research, Summer of 2022, samples were collected from Chrysanthemum plants displaying symptoms of chlorosis and wilt at the Hoveizeh Park in the 17th districts of Tehran Municipality. For the isolation of fungal pathogen, pieces of infected tissues after washing with water and surface sterilization with 1% sodium hypochlorite solution and were placed on different agar media with alternating 12h L/D 12h at 25 ± 1 °C. Isolated fungi were identified by analyzing the morphological characteristics and confirmed by specific primers reported by other researchers. Fusarium oxysporum was identified based on morphological and molecular characteristics. For control the disease-causing fungus in laboratory conditions, the new compound Formycine Gold (ethane peroxyacid 20%) from Pak Gostar Parand Company was used. Experiment was designed in 5 treatments with different concentrations of 1000 to 5000 ppm and untreated control with three replications in the form of a completely randomized design that was added to PDA culture medium. A 6mm plug from the mentioned fungus was placed in the center of the petri dish and placed in an incubator at 25 ± 1 °C. Growth diameter of the fungal colony was measured in four directions perpendicular to each other and the average diameter was calculated. After 7days, when control petri dishes were covered by the fungal colony, experiment was completed. Inhibitory effect of the mycelium growth of the fungus was measured at 1000 ppm concentration by 37%, at 2000 ppm concentration by 59% and at 3000 ppm concentration by 92%. Mycelial growth was not observed in concentrations of 3000, 4000 ppm. In the greenhouse research, a plug from 5-day-old fungal culture (3 mm in diameter) was placed in a two-leaf stage in the crown area of the plant. Fungicide the same concentrations were sprayed on the whole plants three days after the contamination of the seedlings and were added to the crown and soil around the plant. Amount of stem color change from crown to the first knot was measured 30 days after treatment. Pot experiment was performed in a completely randomized design with 3 replications (two seedlings in each pot). Results of the severity of the infection showed that the concentration of 1000, 2000, 3000 and 4000 ppm with an average of 25%, 41%, 76% and 95% inhibition was effective in reducing the severity . At the concentration of 5000 ppm, greenness of the leaves was preserved and the disease was completely inhibited. Findings of this research show that the use of Formycine Gold at a concentration of 5000 ppm has a significant potential as a safe and cost-effective compound in sustainable environment goals to control Fusarium vascular disease.