How to treat black spot disease in roses?
This article introduces the green plant and flower aspects of treating black spot disease in roses. Keep reading!
How to treat black spot disease in roses? What medicine should be used for black spot disease in roses? You will understand after reading this.
During the Qingming Festival, when it rains frequently, roses are most susceptible to black spot disease. The disease is highly harmful to the growth of roses and is very common. We should pay special attention to the prevention and treatment of black spot disease during this time.
Methods to prevent and treat black spot disease in roses
For the pest and disease control of roses, we should focus on prevention over treatment, especially around the Qingming Festival when there is a lot of rain. We need to pay attention to these three points to prevent black spot disease.
1. Timely remove the old leaves at the bottom of the rose plant
In April, roses have already started to form flower buds. Some leaves and buds at the bottom may turn yellow and wither due to insufficient sunlight and poor ventilation. We need to promptly remove these yellowing old leaves and blind branches.
Removing old leaves and blind branches can increase ventilation and reduce the chances of infection by black spot and red spider mites.
2. Timely apply pesticides for prevention
In addition to removing the old leaves and blind branches inside, we also need to apply pesticides for prevention. During the Qingming Festival, the frequency of applying pesticides can be increased to every 7-10 days.
If you have not applied pesticides before, you should start doing so immediately. If you have applied pesticides within the past week, you should also reapply after it rains.
For the prevention of black spot disease, it is recommended to use carbendazim or mancozeb. If the interval between applications exceeds a week, it is suggested to combine with myclobutanil or flusilazole. Carbendazim and mancozeb are protective fungicides, while myclobutanil and flusilazole have stronger fungicidal properties and focus more on treatment. Using both types of drugs together can eliminate black spot disease in its early stages.
3. Immediately remove affected leaves and apply pesticides upon discovering black spot
Even with preventive measures, it is impossible to completely avoid the possibility of infection. Therefore, it is essential to regularly observe, especially focusing on the lower leaves. If black or brown spots are found on the leaves, immediately remove the affected leaves and apply pesticides.
Strong fungicides, such as myclobutanil or pyraclostrobin, should be used. Dilute them according to the instructions and spray the entire plant.
When spraying, make sure to cover both the front and back of the leaves, as well as the surface of the potting soil. Many pathogens and pests initially reside in the soil, so the surface of the potting soil should also be sprayed, but be careful not to flood the roots with fungicides, as it can destroy the microbial environment of the soil.
The above introduction on how to treat black spot disease in roses is provided for netizens' reference.