If you want to avoid the rose you planted, you should pay attention to choosing varieties that are not prone to blemishes, or choose varieties that have stronger resistance to diseases and pests. Even if you have symptoms of black spots, it will be milder.
1, varieties that are not prone to diseases
This kind of rose varieties that are not prone to black spot disease, or varieties that are more strongly resistant to black spot disease include peerless beauty, angel (angel of the Rose Kingdom), beautiful cherry and Florentina. Some rose varieties are more likely to be infected with powdery mildew, such as the common juliette , cute green, winter rouge, begonia rose, and so on.
Black spot disease is easy to identify. Black spots of irregular size appear on the leaves of plants, slowly forming patches. The entire black spots will even pass through the back of the leaves. In addition to roses, other plants will also be infected with black spots. Pay attention to check whether the leaves are infected with diseases.
2. Prevent
When growing roses, you should pay attention to regularly preventing the growth of pests and diseases, especially diseases. In rainy seasons or when the temperature changes relatively large (summer and autumn), spraying medicine in advance should be prevented. It is generally recommended to spray it every one or two months, and it is necessary to prevent problems before they occur.
For example, spray mutantol and mancozeb every half month or a month. You can also use the common methyltobuzi or pheasantol , etc. It is best to choose two or three agents to spray alternately to avoid bacterial resistance.
If you are growing roses in the yard, you should also pay attention to clearing the garden when the temperature is particularly low in the year. If you are in a relatively low place in the north, the temperature drops to about minus 10 degrees below the bottom, or when the coldest in winter, you can spray the entire yard and plant with lime sulfur mixture .
3. Spray the medicine after being infected with black spot disease
Don’t wait for the rose to break out before spraying the medicine. After the disease breaks out, don’t spray ordinary germlin, mancozeb or methyltobuzi. These protective bactericidal drugs are sprayed before being infected with bacteria and are used for prevention.
Rose 0 After being infected with black spot disease, it is recommended to use the common tetrazoleol (which contains the active ingredient of tetrazoleol, such as Dermin), triazole, and azoxester. It should be sprayed alternately with other powerful bactericidal drugs, such as phenyl ether mecyclazole . It is generally recommended to spray one every two days, spray evenly on the leaves, backs, branches and pot soil of the plant. Spray another ingredient three or four times in a row, so as to ensure the removal of bacteria.
4. Use and storage of medicines
If you don’t know how to use medicines, you can first look at the instructions. If it is a small packet, it is usually 40 kilograms of water per packet.
Of course, we cannot use such a large amount, usually one gram or one milliliter of water 1000~1500 ml. The specific one depends on the instructions of the medicine. After mixing the potion with water, you must shake it evenly and spray it in one day. No matter what kind of potion or fertilizer it is, it is recommended to use it in one day, otherwise the effect of the medicine will gradually disappear.
The medicines and fertilizers that are usually placed at home are recommended to be placed in a cool, ventilated, shaded and dry place, and not in a sunny place.
