بررسی تأثیر نماتدکشی اسانس سه گیاه دارویی بر نماتد مرکبات (Tylenchulus semipenetrans)

Among Of the 23 species of citrus nematodes in the world, citrus nematodes Tylenchulus semipenetrans Cobb, 1913 is one of the most important in terms of damage and dissemination, which leads to a reduction in the product and slow decline of citrus fruits. Due to increasing environmental hazards of nematicides and harmful effects on human health, Also, the difficulty of managing nematodes, researchers efforts to achieve appropriate control strategies have increased. In recently decades, the use of essential oils has been introduced. This method has no environmental pollution and its use as part of integrated management of nematodes is more than ever considered. In this study, effect of essential oils of Lavender (Lavandula angustifolia), Eucalyptus (Eucalyptus sp.) and Peppermint (Mentha piperita) on the mortality of citrus nematodes, Tylenchulus semipentrans, were studied. The experiment was conducted as completely randomized design with three replications under laboratory condition. In the present study, 100 number of seconde stage larvae of T. semipentrans added to each petri dish containing 1.25, 2.5 and 5% concentrations of lavender, eucalyptus and peppermint essential oil. Petri dishes were incubated for 2, 4, 24, 48 and 72 hours under controlled condition at 25˚C. Essentiol oil of each three plant were tested at four levels including (0, 1.25, 2.5 and 5%). After 2, 4, 24, 48 and 72 hours, three replicates from each treatment were evaluated and the number of nematodes that were inactive and immobilized were counted for each treatment. After counting the nematodes and recording the number of dead nematodes in each treatment, concentration and replications, the nematodes were transferred to petri dishes containing distilled water and re-counted after 24 hours at room temperature. Results revealed that lavender at the rate of 5% caused 73% mortality of nematode after 24 hours, almost 89% mortality at the rate of 5% of eucalyptus after 48 hours and about 62 % at the rates of 5% of peppermint after 48 hours. The obtained lethal concentrations (LC50) of lavender, eucalyptus and peppermint were 2.5, 1.25 and 5%, respectively.