Regularly rainy weather requires quick prevention of two diseases in Chinese roses.
The editor will introduce you to the knowledge of preventing the two diseases in Chinese roses that often occur during rainy weather, and will introduce the details next.
1. Chinese Rose Powdery Mildew
Chinese rose powdery mildew is most likely to occur during the early spring rainy season. Due to the high humidity, the pathogen of powdery mildew is easily grown. When our Chinese roses are infected with powdery mildew, they usually show the following symptoms.
① Leaf Discoloration Spots
Infected leaves may show spots of discoloration, usually in patches or stripes, which are not very obvious, but still easily noticeable upon close observation. Often, there will be white powder on the back of the leaves.
② Leaf Curling
Some Chinese rose leaves may curl when infected with powdery mildew, and white powder can usually be seen in the curled parts.
③ White Powder on Leaves
As powdery mildew progresses, the white powder gradually moves from the back of the leaves to the front, making it clearly visible that there is a lot of white powder on the leaves.
④ White Powder on Bud Stalks
When powdery mildew infects the buds of Chinese roses, the base of the buds and the flower stems will show the mycelium of powdery mildew, encasing the rose buds, ultimately leading to the withering of the flower buds.
Treatment for Powdery Mildew
When Chinese roses have powdery mildew, if they are grown outdoors, it is recommended to spray pesticides in time. Using myclobutanil, Lunaforest, or Nadiclin diluted can have good results.
If the powdery mildew is severe, you can first rinse the powder off with alkaline water, then rinse with clear water, and wait for the leaves to dry before applying fungicides for better results.
For Chinese roses on indoor balconies, you can wipe the infected areas with alcohol diluted 100-150 times, then spray the entire plant with alcohol diluted 200 times, which can also have a good effect.
2. Chinese Rose Downy Mildew
In seasons with frequent rain and high humidity, not only is powdery mildew likely to break out, but downy mildew in Chinese roses is also very likely to occur.
When Chinese roses are infected with downy mildew, they usually show yellow necrotic spots in the center of the leaves that gradually expand and merge together.
The treatment for Chinese rose downy mildew is relatively simple and can be treated with fungicides such as mancozeb and flusilazole.
The above introduction to the quick prevention of the two diseases in Chinese roses that often occur during rainy weather contains all the information for your comprehensive understanding and reference!