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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Other parts of the plant are not directly affected.
Periods of wet weather are necessary for abundant spore production. Alternaria cucumerina is an important pathogen of some CucumisCucurbita and Citrullus species with a wide distribution, including several European and Asian countries Ellis, An indirect cucumernia is seen the fruit production.
Back to top Cucurbits, Alternaria Leaf Spot. Modeling the relationship between Alternaria leaf blight and yield loss in muskmelon.
Mikologiya i Fitopatologiya 33 Find more of our publications and books at extensionpubs. Fungal isolates with morphological characteristics similar to those of A.
Avoid overhead irrigation, if possible. John Wiley and Sons, New York. Symptoms Another name for this disease is target leaf spot which refers to the appearance of the lesions on the upper surface of the leaves. Reduce relative humidity in greenhouse operations.
The genus Alternaria and allied hyphomycetes from the Russian Far East. Plant Disease 78 Consult your local extension specialist or agent for recommendations relevant to your particular host and state.
They enlarge and contain concentric rings and are surrounded by a yellow halo. North American Amphibian Monitoring Program.
Introduction Alternaria cucumerina is a fungus of world-wide occurrence which can infect most cucurbits. The plants were placed back in the greenhouse where brown spots were observed on all plants three days post-inoculation.
The University of Maine Orono, Maine 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.
Young plants and old plants are more susceptible than are mid-season plants. Survival and Dispersal The fungus survives the winter in infected crop debris as mycelium and may also survive on the seed. The spots are light brown with a light center and form concentric dark rings as they enlarge, thus the name target spot.
UMaine Cooperative Extension: Insect Pests, Ticks and Plant Diseases
Content is available for non-profit, educational use under our Copyright Agreement. Disease severity increases with periods of leaf wetness. Symptoms first appear on older leaves near the crown. Lesions which form on the lower leaf surface tend to be more diffuse. In general, these measurements are within the size range determined by Simmons for A.
Dry pumpkin leaves affected by alternariosis Alternaria cucumerina and powdery mildew. The source of the disease is considered to be dormant mycelium in cucurbit fields and airborne conidia. Fungicide treated disease-free seed may be helpful.
Vegetable: Cucurbits, Alternaria Leaf Spot | UMass Center for Agriculture, Food and the Environment
The occurrence of this disease in Georgia is sometimes sporadic but can be devastating if left unchecked.
New Disease Reports 23 Direct infection of the fruit also occurs especially melons but much less frequently. Alternaria leaf spot may cause reduced yield and smaller fruit. Lesions tend to appear first on the older leaves as small circular spots. Lesions can coalesce and the leaves develop a cupped appearance and die. Cooperative Extension and other agencies of the U.
Effect of Alternaria leaf blight on soluble solid content of muskmelon. Information in this publication is provided purely for educational purposes. After seven days, large solitary conidia were formed on the surface of the agar. Alternaria cucumerina is a fungus of world-wide occurrence which can infect most cucurbits.
Discussion View source History. Rotations which exclude cucurbits for years may be beneficial.
Environmental Conditions Infection by A. Most fungicides used in disease management will suppress Alternaria leaf spot; however, chlorothalonil containing products are generally the most effective.
To our knowledge, this is the first documented detection of Cucumerinaa. Remove or deep plow plant debris to speed decomposition. Rotate with non-host crops for at least two years. Conidia spread by wind and rain splash produce secondary cycles of infection whenever conditions are favorable for disease cucumerins. The fungus survives the winter in infected crop debris as mycelium and may also survive on the seed.