Protect Your Poinsettias From Key Diseases
A look at the diseases poinsettias encounter most and learn strategies to combat them.
July 27, 2012
Pythium. Apply Subdue Maxx at 1 ounce/100 gallons as a soil drench after planting. Rotate with Truban WP (6 to 8 ounces/100 gal.) or Segway (3 ounces/100 gallons) fungicides every four weeks for protection.
Botrytis. Be sure to maintain good air movement and low humidity. To avoid botrytis, apply preventative fungicide sprays of Daconil ULTREX alternated with Palladium (4 to 6 ounces/100 gallons), Heritage (4 ounces/100 gallons), Chipco 26019 or Decree (1 lb./100 gallons) after sticking and seven to 10 days later.
Powdery Mildew. To prevent outbreaks, maintain good air movement and low humidity in the production area. Apply preventive fungicide treatments throughout the month of October if there is a history of powdery mildew. Effective fungicide spray treatments include Heritage (4 ounces/100 gallons), Palladium (4 to 6 ounces/100 gallons) and several products from FRAC group 3: Eagle 20EW (8 ounces/100 gallons), Terraguard (8 ounces/100 gal.) and Strike 50 WDG (0.5 fluid ounces/100 gallons).
Rhizoctonia. To prevent root and stem infections by Rhizoctonia spp., avoid planting too deeply and maintain proper EC levels and moisture content of the media. Drench with Heritage (0.9 ounces/100 gallons), Medallion (1 ounce/100 gallons) or a thiophanate-methyl product (e.g., Cleary’s 3336 WP or OHP 6672) at full label rate. Alternate these products on a four-week interval for prevention.