What medicine is good for the rose downy mildew disease
Answering the topic of rose downy mildew disease treatment for netizens, let's take a look together!
What medicine is good for the rose downy mildew disease
Previously, a flower enthusiast asked in the **iAsk Circle about a question: "There is a white spot on the leaves of the dahlia, and I don't know the reason."
From the picture above, we can see that there is indeed a layer of white substance covering the leaf, which looks similar to severe spider mite symptoms at first glance.
(Spider mite symptoms)
But if you look carefully, you will find the difference. If it is caused by spider mites, there will definitely be chlorotic yellow spots on the leaves, but obviously, there are no yellow spots on the dahlia leaves of this flower enthusiast.
Interestingly, another flower enthusiast asked a similar question yesterday, this time it was about roses. There were many white things on the leaves of the roses, and not only did the symptoms manifest similarly, but both flower enthusiasts were from the north.
So what exactly caused this? What is this layer of white substance?
What medicine is good for the rose downy mildew disease
Actually, this is a relatively common disease - downy mildew.
Downy mildew is a disease caused by the fungal infection of the Peronospora, which develops rapidly and causes significant damage, with cucumbers being one of the main objects affected.
Understanding downy mildew
Downy mildew can occur from seedlings to adult plants, with the most severe damage to adult plants, primarily affecting the leaves.
Usually, in the early stages of the disease, yellow round or angular lesions will form on the leaves. When roses are infected with downy mildew, the center of the leaves will show a涂抹-like chlorotic yellow spot, sometimes covered with a frosty mold layer. In the later stage, the leaves will turn dark purple, like water-stained patches.
However, the development of downy mildew is greatly related to temperature. The latent period of the pathogen spores varies from 3 to 5 days, and the latent period is only 3 days when the temperature is above 20 degrees Celsius.