عزل و تعريف مسبب مرض تبقع و لفحة أوراق اليوكالبتوس (Harknessia eucalypti)‎ في ليبيا و تأثير درجة الحرارة في نموه مخبريا

الملخص EN

The study was conducted at al-Qardabiya nursery for forest production in the sirte region in Libya to determine the causal agents of eucalyptus stricklandii trees infected with leaf blight and leaf spot diseases during march 2016, where the disease incidence reached 100% in all trees.

diseases severity observed was 10% on the upper and 30% on the lower leaves of the tested trees.

results of the microscopic isolation showed that harknessia eucalypti pathogenic fungus was present in 80% of all the tested plant pieces, and was associated with alternaria sp.

in 20% of the tested samples.

the results of the effect of temperature on the pathogen growth at three temperatures (20, 25, 30°c) where the fungus has produced a white mycelium with diameter growth of 9, 9 and 1.3 cm, respectively, in a six days period, and the fungal growth stopped completely at 35-40°c.

the fungus pathogenicity was reproduced on the leaves of e.

camaldulesis.

this is the first report on the occurrence of harkenssia eucalypti pathogenic fungus in Libya.