Agronomic Planning to Prevent Impatiens Downy Mildew

Impatiens, one of the most popular bedding plants, are susceptible to a variety of diseases during greenhouse production, including the devastating impatiens downy mildew (IDM). Along with proper cultural practices, a strong rotation management program is the key to producing impatiens successfully.

Signs of Infection

IDM symptoms can be delayed or masked by high fertility levels, so it is imperative to monitor crops closely. Leaf discoloration or spotting, often within the veins, are the most common initial symptoms, as well as:

  • Pale foliage with yellow, tan or red blotchy areas
  • Distorted, wilting or downward curling of the leaves
  • White or light gray/purple fuzz on the undersides of leaves
  • Small emerging leaves
Rechcigl Downy Mildew on Impatiens
Syngenta photo. Rechcigl, 2018. Saratoga Springs, NY

Recommended Rotation

Implementing a rotation program that uses a ‘systemic sandwich’ approach is one of the best ways to prevent impatiens downy mildew from spreading. With this approach, systemic fungicides are applied as a drench at transplant or at the beginning of production and again prior to shipping. Other fungicides with translaminar activity should be applied as sprays in between. The use of systemic products provides extended protection through shipping.

Be Secure with Segovis

Recent innovations in plant protection products and genetics provide the tools needed to successfully produce impatiens in the greenhouse and grow them in the landscape. Segovis® fungicide in FRAC group 49 should be a key product in your agronomic program, as it offers a unique mode of action to diversify rotation programs and protect impatiens for up to twelve weeks when applied as a drench as the final treatment prior to shipping.

As you plan ahead to control IDM, include Segovis in an agronomic program such as the one below that rotates products with different modes of action to prevent resistance and preserve valuable chemistries.

Rotation Pattern

Start preparing for IDM by downloading the impatiens agronomic program today and learn more about Segovis at

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