10 Common Marigold Plant Damaging Diseases: Symptoms, Treatment, Prevention, and Management

Welcome to our blog post on Common Marigold Plant Diseases! Marigolds, with their fabulous blooms and diverse varieties, are lovely additions to gardens, but like any plant, they can be prone to a range of common diseases that can hinder their beauty and health. This blog post aims to discuss the 10 common marigold plant damaging diseases, including their symptoms, treatments, prevention, and management. So, get ready to explore these marigold plants’ ten most common diseases.

10 Common Marigold Plant Damaging Diseases

Important Points for Beginners to Identify and Manage Diseases in Marigold Plants

  • Identifying the disease: The first step is identifying the disease infesting your marigold plant so that you can approach it with the most effective control method.
  • Regular Monitoring: Monitor your Marigold plants regularly for signs of diseases. This will help you to identify an infestation early when it is easier to control.
  • Sanitation: Remove the infected plant debris and burn them.
  • Natural Control: Several natural control methods can help to manage diseases. These include plant extracts, essential oils, composting, and organic fungicides.
  • Chemical Control: If natural controls are ineffective, use fungicides as a last resort, and follow the label instructions and dosage carefully.

10 Common Marigold Plant Damaging Diseases

Damping-off Disease in Marigold Plant

  • Disease Symptoms by Rhizoctonia Solani: Damping-off starts with the rotting of seeds before they can germinate. The affected plants may show discolored, soft, mushy seeds and rotting and girdling of the stem. Affected seedlings may show a water-soaked appearance and a “damping-off” effect.
  • Survival and Spread: Rhizoctonia solani prefers a warm and moist environment of 20-30°C for their growth. Organic matter and excessive moisture retention in the soil hinder proper aeration and create a conducive environment. Dense plantations, plant stresses, and infected plant debris promote disease development.
  • Treatment, Maintenance, and Control Measures: Spray thiophanate-methyl, iprodione, metalaxyl, fludioxonil, copper oxychloride, dithane, formalin, captan, and carbendazim.

Collar Rot Disease in Marigold Plant

  • Disease Symptoms by Phytophthora sp. and Pythium sp.: The plants develop lesions or cankers at the collar region, causing decay, rotting, and girdling of the collar region. Infected plants often show signs of wilting, chlorosis, stunted growth, and death.
  • Survival and Spread: Phytophthora and Pythium sp. prefer warm temperatures and moist soil of 20-30°C and 85% humidity for their growth and reproduction. Dense canopy, excessive rainfall, poor soil drainage, poor structure, compaction, or high clay content can contribute to the disease.
  • Treatment, Maintenance, and Control Measures: Spray metalaxyl, mefenoxam, fosetyl-aluminum, propamocarb, cyazofamid, fludioxonil, and thiophanate-methyl.

Flower Bud Rot Disease in Marigold Plant

  • Disease Symptoms by Alternaria dianthi: The first noticeable symptom is the appearance of brown or black lesions on the flower buds. The affected areas become sunken and necrotic. The infected flower buds undergo rotting, decay, and collapse of the entire flower bud structure.
  • Survival and Spread: Alternaria dianthi prefers a warm and humid climate of 20-30°C and >70% humidity for their survival. Prolonged dew formation, dense canopy, overhead irrigation, injuries, infected plant debris, wet leaves, and flower buds contribute to the disease.
  • Treatment, Maintenance, and Control Measures: Spray copper hydroxide, copper oxychloride, azoxystrobin, thiophanate-methyl, propiconazole, tebuconazole, chlorothalonil, dithane m-45, and mancozeb.

Powdery Mildew Disease in Marigold Plant

  • Disease Symptoms by Oidium sp.: The characteristic symptom of the disease is the white or grayish powdery coating on the plant’s leaves, stems, and flowers. Infected leaves may become distorted, wrinkled, stunted, yellow, curl, and drop prematurely. Infected buds will deform and show discoloration.
  • Survival and Spread: Oidium sp. prefer moderate temperatures and high humidity of 20-25°C and 50-70% humidity to germinate and infect the plants. Prolonged leaf wetness, poor airflow, and dense canopy create an ideal habitat.
  • Treatment, Maintenance, and Control Measures: Spray myclobutanil, tebuconazole, propiconazole, karathane, sulfur dust, sulfex, azoxystrobin, chlorothalonil, and mancozeb.