Evaluation of The Antifungal Effect of Poisons Used in Pistachio Orchards in Qazvin

BACKGROUND AND OBJECTIVEOne of the most valuable agricultural assets are pistachio trees which are contaminated by various types of fungal agents. Fungi cause drying of green leaves during the growing season, gum secretion from the crown of the tree, and root rot. To eliminate fungal contamination, fungicides are used abundantly without considering their effects. In Iran, three types of anti-fungal compounds, Previcur, Elite, and Bordeaux, are used to eliminate fungal contaminations. This study aims to investigate the antifungal activity of three types of poisons on isolated fungi from the leaves and roots of pistachio trees in Qazvin.MATERIALS AND METHODSThe parts of the root and leaves of the trees suspected of having fungal contamination were separated from the tree and transferred to the PDA medium. After the growth of the fungi in the culture medium, colonies form and microscopic characteristics were evaluated. The efficiency of each fungicide was evaluated with a method of mixing with the culture medium. The equal pieces of the PDA, containing the isolated fungi, were transferred to the PDA containing different concentrations of three types of fungicide, individually. The plates were incubated for a week at ۳۰ºC. The growth of the fungi was evaluated and was reported.RESULTS AND DISCUSSIONBased on microscopic observations and colony structure, two types of fungi, with characteristics of Aspergillus Sp. were identified. The highest antifungal effect was observed when using the Previcur toxin by ۳% in the isolated fungi from the leaves of pistachio trees. None of the three poisons had an antifungal effect in reducing the growth rate of the fungus colony isolated from the tree root. Results approved many of the poisons that used in the pistachio orchards have no efficiency to eliminate microbial contaminants. Najarpour et al., have also reported employing salt compounds in different types and concentrations to control the contaminations in pistachio trees should be evaluated to avoid environmental pollution.CONCLUSIONIndiscriminate use of pesticides to eliminate fungal contamination without considering the effectiveness of pesticides will not eliminate contaminations but will cause irreparable damage to pistachio trees and the environment. Therefore, it seems necessary to reflect on the efficiency of pesticides before use.

کلیدواژه ها:

Antifungal effects ، Poisons ، Pistachio trees ، Aspergillus ، Environment