Algal leaf spot is most severe on magnolias that are weak and in poor vigor.
19+ Magnolia Leaf Spot Disease. Among these, leaf spot and leaf blight are the two most common. You can control many magnolia diseases with basic precautionary measures and timely disease management.
Q A What Are These Spots On My Magnolia Leaves Youtube from i.ytimg.com
While various types of fungi can infect magnolia trees, phyllosticta, septoria and coniothyrium are the most common among others. You can control many magnolia diseases with basic precautionary measures and timely disease management. A leaf spot is a limited, discoloured, diseased area of a leaf that is caused by fungal, bacterial or viral plant diseases, or by injuries from nematodes, insects, environmental factors, toxicity or herbicides.
The causal organism is cephaleuros virescens, a green parasitic alga whose usual hosts are plants with leathery leaves such as cotoneasters, magnolias, hollies, rhododendrons and viburnums.
The host is a southern magnolia (magnolia grandiflora). A leaf spot disease was observed attacking some magnolia aff. Early blooming magnolia trees run the risk of damage by spring frosts in the north. For their efficacy in controlling the cercospora leaf spot disease of the marigold.
