Botrytis Blight
Fungus: Botrytis cinerea also known as Bud Blight or Flower Blight or Grey (Gray) Mold, and also when the cane is affected: Cane Canker. The first symptom you will probably notice is a characteristic set of pink spots on white and lighter colored blooms. Sometimes there is a pink ring that forms around these spots. These can also appear as yellow or brown flecks as they age. At times this can even look quite artistic. Other main symptoms will be balling of the buds or failure of the buds to open. The petals can then turn brown at the bottoms of the bud like shreds of a paper bag. In serious cases, infected leaves can appear as if they are rotting away. Sometimes there can be a grayish brown fuzzy growth on parts of the infected portions. Lower petals on these blooms dead and brown. A gray mold can also occur at the base of canes that are covered by leaves or mulch. The problem is most severe in humid and cool (60 degrees F) conditions. The disease tends to start high and run down the stem so that over time, more and more of the plant becomes infected. The blight survives winter as black lumps in the soil or on dead infected canes and buds that have not been pruned off.
Treatment: Cut out and destroy all infected plant parts. Also open up the plant so it has good ventilation and air circulation. Preventative spraying isn't very effective, but will work in some climates and cases. Chemical spraying is with copper hydroxide or lime sulpher early in the season.
Roses and everything about them.
Votes:28
Comments: 0