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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The source of the disease is considered to be dormant mycelium in cucurbit fields and airborne conidia.
Fungal isolates with morphological characteristics similar to those of A. Plant Disease 76 Some resistant varieties are available. Based on work by Michasia Harris and Bugwoodwiki user Jbrock. Alternaria Leaf Spot is caused by Alternaria cucumerina and algernaria cause serious damage under extended periods of wet weather.
Cucurbits, Alternaria Leaf Spot
Cooperative Extension and other agencies of the U. High relative humidity is required cudumerina the production of conidia, which will be spread by wing and rain.
Alternaria cucumerina Alternria cucumerina is most common on melons and watermelons, although it can affect most cucurbit crops. Content is available for non-profit, educational use under our Copyright Agreement. Another name for this disease is target leaf spot which refers to the appearance of the lesions on the upper surface of the leaves.
The observed leaf spots were up to mm in diameter with a round greyish to pale brown centre and dark brown edges. Alternaria cucumerina is a fungus of world-wide occurrence which can infect most cucurbits. Rotate away from cucurbits for 1 to 2 years.
There are no resistant cultivars available.
Fungicide treated disease-free seed may be helpful. Periods of wet weather are necessary for abundant spore production. Disease severity increases with periods of leaf wetness. They enlarge and contain concentric rings and are surrounded by a yellow halo.
Lesions which form on the lower leaf surface tend to be more diffuse. Direct infection of the fruit also occurs especially melons but much less frequently.
Rotations which exclude cucurbits for years may be beneficial.
Alternaria cucumerina (Alternaria Leaf Blight of cucurbits)
The University of Maine Orono, Maine Most fungicides used in disease management will suppress Alternaria leaf spot; however, chlorothalonil containing products are generally the most effective. Defoliation, in turn, leads to a reduction in yield and may cause fruit to ripen prematurely. Dry pumpkin leaves affected by alternariosis Alternaria cucumerina and powdery mildew.
Young plants and old plants are more susceptible than are mid-season plants. Vegetable Disease and Their Control. No endorsement of products or companies is intended, nor is criticism of unnamed products or companies implied.
Alternaria cucumerina (Alternaria Leaf Blight of cucurbits) – Bugwoodwiki
The interactions of Bipolaris sorokiniana strains and wheat samples. The occurrence of this disease in Georgia is sometimes sporadic but can be devastating if left unchecked.
Environmental Conditions Infection by A. In general, these measurements are within the size range determined by Simmons for A. For information about UMaine Extension programs and resources, visit extension.
Mikologiya i Fitopatologiya 33 Conidia spread by wind and rain splash produce secondary cycles of infection whenever conditions are favorable for disease development. Insect Pests, Ticks and Plant Diseases. Find more of our publications and books at extensionpubs. Back to top Cucurbits, Alternaria Leaf Spot. Information in this publication is provided purely for educational purposes.
The spots start as small, necrotic flecks.
Alternaria cucumerina – Wikipedia
Fall plowing will bury the remaining debris and promote its breakdown. John Wiley and Sons, New York. Leaf spots first appear on the older leaves in the middle and upper part of the plant. After seven days, large solitary conidia were formed on the surface of the agar.