Alternaria cucumerina. Rui map Zheng. Alternaria leaf blight. Alternaria cucumerina. Gerald Holmes. Alternaria leaf blight. Alternaria cucumerina. Gerald Holmes. Alternaria cucumerina is an important pathogen of some Cucumis, Cucurbita and Citrullus species with a wide distribution, including several. Alternaria leaf spot or blight of cucurbits or vine crops is caused by the fungus Alternaria cucumerina. The disease is widespread and often damaging in.

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For information about UMaine Extension programs and resources, visit alternadia. No endorsement of products or companies is intended, nor is criticism of unnamed products or companies implied.

Initially yellow brown and small with a green to yellow halo, lesions expand into large, brown necrotic areas. North American Aquatic Connectivity Collaborative. Refer to the table below for some labeled fungicides.

Alternaria Leaf Spot is caused by Alternaria cucumerina and can cause serious damage under extended periods of wet weather. Some resistant varieties are available.

No responsibility is assumed for any cycumerina associated with the use of products or services mentioned. Most fungicides used in disease management will suppress Alternaria leaf spot; however, chlorothalonil containing products are generally the most effective.

Older leaves had a higher number of cucumerins spots than younger leaves. Consult your local extension specialist or agent for recommendations relevant to your particular host and state.

The fungus has been found in the Far East of Russia on Cucumis melo, Cucumis sativus and Citrullus lanatus Egorova, ; however it has not been reported from other areas of Russia.


Plant Disease 76 Symptoms Another name for this disease is target leaf spot which refers to the appearance of the lesions on the upper surface of cucumerinna leaves.

The interactions of Bipolaris sorokiniana strains and wheat samples. References Egorova LN, The source cucumeria the disease is considered to be dormant mycelium in cucurbit fields and airborne conidia. The use of fungicides will reduce disease incidence when the applications are appropriately timed. In the picture above, A.

Alternaria cucumerina is a fungus of world-wide occurrence which can infect most cucurbits. Cooperative Extension and other agencies of the U. Spores are readily wind-blown and splashed by rain.

See label for resistance guidelines. No symptoms were observed on non-inoculated plants. Survival and Dispersal The fungus survives the winter in infected crop debris as mycelium and may also survive on the seed.

Cucurbits, Alternaria Leaf Spot

Fruit infections begin as sunken brown spots and may later develop a dark powdery appearance as the fungus sporulates. The plants were placed back in the greenhouse where brown spots were observed on all plants three days post-inoculation.

The spots start as small, necrotic flecks. To our knowledge, this is the first documented detection of A.

Lesions can coalesce and the leaves develop a cupped appearance and die. Control plants were sprayed only with water. It is prevalent in regions with abundant rainfall and high temperatures. Introduction Alternaria cucumerina is a fungus of world-wide occurrence which can infect most cucurbits.


Direct infection of the fruit also occurs especially melons but much less frequently. Rotate with non-host crops for at least two years.

In general, these measurements are within the size range determined by Simmons for A. Direct infection is primarily of the leaves and can lead to defoliation. Discussion View source History. Department of Agriculture cooperating.

Mikologiya i Fitopatologiya 33 Fruit may also be damaged due to exposure to the sun and wind. Temperatures of oF are optimal along with 8 hours continuous leaf wetness. Content is available for non-profit, educational use under our Copyright Agreement. Retrieved January 30,from http: Periods of wet weather are necessary for abundant spore production.

Management of any pathogen is often dependent upon both cultural and chemical options. The overwintering fungus serves alternarria the source of primary infections and spores from these infections cycle the disease through the growing season. Leaf blight was accompanied by powdery mildew.

Vegetable: Cucurbits, Alternaria Leaf Spot | UMass Center for Agriculture, Food and the Environment

The observed leaf spots were up to mm in diameter with a round greyish to pale brown centre and dark brown edges. Control Remove crop refuse at the end of the season.

Common Names and Alternwria. After seven days, large solitary conidia were formed on the surface of the agar.

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