بررسی ترکیب فرموله شده زیستی بر پایه اسید کربوکسیلیک در کنترل Alternaria tenuissima جداشده از درختان سرو

Conifers, a component of beauties of parks and landscapes, are infected with diverse pathogens, especially fungi. In this research, during the spring and summer of 2018 and 2019, samples were collected from conifers displaying symptoms of discoloration of the needles to yellow and then reddish-brown,in the parks of 13th and 4th districts of Tehran Municipality. For the isolation and identification of pathogenic fungi, pieces of infected tissues were placed on Potato Dextrose Agar. In order to identify the specimens, the morphological characteristics of the fungi such as colony color and shape, color and dimensions of conidia and conidiophores were used. The studied fungus was identified as Alternaria tenuissima. For the control of fungal growth in laboratory conditions, a biodegradable compound based on carboxylic acid with the commercial name Bioprof was used. The experiment was designed in five treatments with different concentrations of 1000, 2000, 3000, 5000 and 7000ppm and untreated control with 3 replications in the form of a completely randomized design that was added to the Potato Dextrose Agar (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˚ C. The growth diameter of the fungal colony was measured in four directions perpendicular to each other and the average diameter was calculated. After seven days, when control petri dishes were covered by the fungal colony, the experiment was completed. The inhibitory effect of mycelial growth of this substance at 2000 and 3000 ppm concentration after 7 days was measured as 88% and 91% respectively. There was no growth at 5000 and 7000 ppm concentrations. Due to the importance of reducing chemical pesticides to protect the environment, this compound can be used to manage the disease.