常見的葉斑病是由真菌Mycospharella fragariae引起的，它可以通過感染的草莓植物或來自附近草莓的風吹散播的孢子進入花園。一旦進入花園，這種真菌主要通過雨水或灑水濺起的水滴傳播。當溫度在65°F至75°F之間，且有高降雨和濕度時，M. fragariae最活躍。M. fragariae在冬季存活在死去的草莓葉子和其他植物部分上，並在春季由早期雨水帶到新的葉子上。
常見的葉斑病是由真菌Mycospharella fragariae引起的，它可以通過感染的草莓植物或來自附近草莓的風吹散播的孢子進入花園。一旦進入花園，這種真菌主要通過雨水或灑水濺起的水滴傳播。M. fragariae在溫度在65°F至75°F之間、降雨量和濕度較高的環境中最活躍。它在冬季可以在死去的草莓葉子和其他植物部分上存活，並在春季的早期雨水中傳播到新的
Common leaf spot is caused by the fungus Mycospharella fragariae, which can enter a garden on infected strawberry plants or via windblown spores from nearby strawberries. Once introduced into a garden, the fungus is spread predominantly by splashing water from rain or sprinklers used for watering.Oct 14, 2016
Articles > Diseases & Disorders
Common leaf spot of Strawberry
John Hammel, UW-Madison Plant Pathology
Item Number: XHT1236
What is common leaf spot? Common leaf spot of strawberry (also known as Mycosphaerella leaf spot, Ramularia leaf spot, strawberry leaf spot, bird’s-eye spot, gray spotness, and white spot) is a common fungal leaf disease that affects both wild and cultivated strawberries throughout the world. Common leaf spot was once the most economically important strawberry disease, but the use of resistant strawberry varieties/cultivars and improvements in methods for growing strawberries have been effective in managing the disease and reducing its impact. Today, the disease is often a cosmetic problem and typically has little impact on yield or fruit quality.
What does common leaf spot look like? Symptoms of common leaf spot can occur on leaves, fruits, berry caps, petioles, and runners. The most noticeable symptoms of the disease are small, round, necrotic (i.e., dead) spots on strawberry leaves. Initially, these spots develop on the upper leaf surface and are deep purple to red in color. The spots eventually develop tan, gray or almost white centers with distinct reddish-purple to brown borders. During warm, humid weather, uniformly rusty-brown spots without purple margins or light colored centers may develop instead. Spots can occur on the undersides of the leaves as well, but these spots tend to be less vibrant in color. As the disease progresses, spots enlarge to ⅛ to ¼ inch in diameter and may merge together, in extreme cases leading to leaf death. Spots on berry caps, petioles, and runners resemble those produced on upper leaf surfaces. Shallow, black spots (¼ inch in diameter) may develop on infected fruits, and are often surrounded by brown or black, leathery tissue.
Where does common leaf spot come from? Common leaf spot is caused by the fungus Mycospharella fragariae, which can enter a garden on infected strawberry plants or via windblown spores from nearby strawberries. Once introduced into a garden, the fungus is spread predominantly by splashing water from rain or sprinklers used for watering. M. fragariae is most active when temperatures range from 65°F to 75°F, with periods of high rainfall and humidity. M. fragariae survives the winter on dead strawberry leaves and other plant parts, and is moved to new foliage in the spring by early season rains.
How do I save strawberry plants with common leaf spot? Once common leaf spot develops on strawberry plants, the plants cannot be cured. If the disease is detected early, its development may be slowed using fungicides. Keep in mind however, that common leaf spot is often merely a cosmetic issue and the use of fungicides may not be warranted. If you decide that fungicide treatments are needed, select a product that is labeled for use on strawberries and that contains captan, myclobutanil or copper as the active ingredient. Use copper-containing fungicides only prior to flowering. If you decide to use a myclobutanil-containing product, alternate applications of this product with applications of a second fungicide containing another active ingredient. This will help prevent selection of myclobutanil-resistant variants of the common leaf spot pathogen. Be sure to read and follow all instructions on the label(s) of the fungicide(s) that you select to ensure that you use the product(s) in the safest and most effective ma
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