In Iran, Armillaria disease has been observed on the roots of pear trees in the cities of Isfahan, Tehran, Tabriz and Shandiz Razavi Khorasan. No significant damage was reported. The cause of this fungal disease is called Armillaria mellea. This fungus is earthy and can survive long in the soil. The method of Armillaris rot of trees agent transmission is through the roots inside the soil. When the roots touch each other, the pathogenic fungus is transferred from the diseased roots to the healthy roots. This method is for adjacent trees. Alternatively, the pathogen enters the garden through irrigation, entry of infected seedlings and soil.
The spread of root Rosellinia rot disease in Iran is high, but it does not cause significant damage as only one or two trees with each disease may be reported from each garden. The provinces in which the disease has been reported include Isfahan, Karaj, Qazvin and Tehran. The causative agent of Rosellinia nectarix pear disease is called Rosellinia nectarix. Its sexual form is Dematophora nectarix. This fungus produces Prietz and Cinema, which are rarely found in nature. to control this disease use biological fungicides like Trichodermaroot.
The disease, also called pear mummy, is not common in pear orchards in Iran. Specimens of pests infected with this pathogen were found in Guilan province and Noshahr province and after investigation, Molinia frutigena was identified. The sexual form of this fungus called Monilinia fructigena has not been found on pears in Iran. The disease is similar to moniliac or brown rot of apples.
Alternaria rot of fruit is found in all countries with apple or pear gardens.
Symptoms of Alternaria rot: Symptoms on fruits are round, brown to black. They are dry and firm and shallow. These spots develop around the area of ruptured and damaged skin and the bumps of the abdomen and the tail of the fruit. Occasionally in the central circle around the ovary, a blackish-gray mold will grow and rot the fruit. But in a pear, the rotting of Alternaria rot starts from where the tail is cut and moves on to the rest.Occasionally in the central circle around the ovary, a blackish-gray mold will grow and rot the fruit. But in pear, the rotting starts from where the tail is cut and moves on to the rest.
Factor of the disease: The causive agent of Alternaria rot of pears the is Alternaria alternate. Another name is A. tenuis Nee. The conidiophores of this fungus are simple or branched. These conidiophores are formed individually or collectively. There are one or more conidia effects on conidiophores. The conidia of the fungus are chained and their surface is flat or warty. They are also golden brown.
Disease cycle of Alternaria rot of apples: It is a saprophytic fungus and is also known as a weak pathogen. Its habitat is dead and weakened tree tissues and feeds on apples and pears after or before harvest. This fungal pathogen enters the tree through weak or damaged tissues. These weak tissues can be injured or weakened by mechanical, chemical, physiological aging or sunburn.
Control of Alternaria rot of fruits: Avoid scars on the fruit during harvest.
Clean the boxes and equipment for transportation of fruits and clean with appropriate disinfectants.
If you use benzimidazole group fungicides to control stockpiling and postharvest disease, this will aggravate the alternative caries disease.