Method for controlling diseases in marigolds
As a common ornamental plant in gardens, marigolds are deeply loved by horticulture enthusiasts for their bright golden flowers. However, common diseases such as powdery mildew and mosaic disease often cause the leaves to turn yellow and wither, severely affecting the ornamental value of the plant. This article systematically sorts out the identification characteristics and control methods of the three most common diseases, helping you scientifically protect the healthy growth of marigolds.
Control plan for powdery mildew in marigolds
Symptom identification and harm characteristics
The disease is most prevalent in spring and autumn, with initial symptoms being white powdery mold spots on both sides of the leaves, which develop into irregular patches as the condition progresses. Infected plants show slow growth and malformed flowers, and in severe cases, the entire plant may die. Special attention should be paid to plants in indoor care from March to April, as closed environments are more likely to trigger disease transmission.
Three steps for comprehensive prevention
1. Maintenance prevention: Maintain 6 hours of sunlight per day, control the amount of nitrogen fertilizer, and apply phosphorus and potassium fertilizers to enhance disease resistance. 2. Physical treatment: Promptly remove diseased leaves and spent flowers, and disinfect tools after pruning with 75% alcohol. 3. Pesticide spraying: Alternate the use of 70% methylthiophanate-methyl 1000x solution and 25% pyraclostrobin suspension, focusing on the undersides of leaves.
Strategies for dealing with marigold mosaic disease
Analysis of virus transmission characteristics
The disease is caused by viruses transmitted by piercing-sucking insects such as aphids, with typical symptoms including yellow-green mottling of leaves and stunted plant growth. Laboratory tests show that the sap of infected plants remains contagious even when diluted 1000 times, requiring immediate isolation and treatment.
Preventive management measures
• Set up yellow sticky traps to monitor pest infestations. • Regularly spray 10% imidacloprid 2000x solution to kill virus-carrying vectors. • Soak new seedlings in a 10% trisodium phosphate solution for 15 minutes for disinfection.
Systematic control of rust disease in marigolds
Disease development patterns
In the high temperature and humidity of early summer, the appearance of orange-yellow rust sporophore piles on the leaves is a typical characteristic of the disease. Research shows that at daytime temperatures of 25-28°C and relative humidity greater than 80%, the spore spread rate of the pathogen increases by * times.
Scientific medication guidelines
Use 30% flusilazole microemulsion 5000x solution at the initial stage of the disease, focusing on the base of the plant. Combine with 80% mancozeb wettable powder for protective prevention, taking care to avoid the use of mixed pesticides that may cause antagonistic effects.
By establishing a disease monitoring log, record the time and effect of each pesticide application. It is recommended to use drip irrigation to control soil moisture, maintain a plant spacing of more than 30cm to enhance ventilation, and regularly apply EM bacteria solution to the roots to enhance plant immunity. Combining biological and chemical control can achieve the sustainable cultivation of healthy marigolds.