Tips for Preventing Perennial Diseases
Recognizing and managing diseases on perennial crops early in production is essential. Leaf spots and powdery mildew are two of the most common diseases faced by nursery growers that can affect a wide variety of ornamental crops and trees. By implementing a fungicide rotation program, you can prevent damage on nursery crops and keep your operation free of disease.
Powdery Mildew Problems
Several different fungi cause powdery mildew and many common nursery crops are susceptible, including crape myrtle and roses. It is important to scout for symptoms, including:
- White powdery spots or coating on primarily on the top of leaves, stems and young buds
- Yellow or brown leaves
- Distorted leaves and flower buds or underdeveloped flowers
- Stunted growth
Powdery mildew is difficult to control once it is severe or has reached epidemic status, so preventive applications are imperative.
Leave Leaf Spots Behind
Most fungi associated with leaf spots need water on leaf surfaces to infect the plant, so these diseases are often seen during wet, humid conditions. They appear as dead areas with defined margins scattered over the surfaces of leaves, varying in size and color. Watering early in the day so leaves dry more quickly is recommended to prevent infection by leaf spot pathogens.
Fungicide Rotation Program
Rotating Concert® II, Palladium® and Mural® fungicides creates a comprehensive solution for preventing these nursery diseases. The program below is preventive, but for active infections, shorten the application interval to 7 days and use the higher labeled rates.
1 Concert II is not for use in greenhouses. Use Daconil Weatherstik® or Daconil Ultrex® fungicide for greenhouse applications.
2 Foliar applications or excessive run-off of Palladium sprays may cause stunting or chlorosis to some geranium varieties and New Guinea Impatiens seedlings.
Find more rotation programs for your operation at www.GreenCastOnline.com/Solutions.
©2018 Syngenta. Important: Always read and follow label instructions. Some products may not be registered for sale or use in all states or counties and/or may have state-specific use requirements. Please check with your local extension service to ensure registration and proper use. Concert®, Daconil Ultrex®, Daconil Weatherstik®, GreenCast®, Mural®, Palladium® and the Syngenta logo are trademarks of a Syngenta Group Company.