7/2/2013 - By Matthew Shultz

Cylindrocladium is traditionally classified as a leafspot disease, but as new strains start to emerge, growers are starting to realize that this disease can take on many forms. In herbaceous plants and Ilex, Cylindrocladium appears as a colored leafspot. In Azaleas it can cause a dieback of roots and vascular system, in Rhododendron cankers form on the stem and crown, in Buxus it causes severe defoliation (Boxwood Blight) while in tropical crops like Spathiphyllum basal and crown rots can occur.

This disease attacks a wide range of host plants, 100+ documented plant species. Some notable strains of Cylindrocladium include Cylindrocladium buxicola which is known to cause Boxwood Blight; Cylindrocladium scoparium which infects Azaleas, Rhododendron and Roses; Cylindrocarpon destructans which is typically on herbaceous and bedding plants; and Cylindrocladium spathiphylli on Spathiphyllum.

Cylindrocladium usually occurs during the warmer months of the year, when extended wet periods occur.Control is usually easily attainable when good cultural practices are used alongside a good spray regime. BMP’s include using sterile potting media, removing infected plants and fallen leaf litter, minimizing leaf moisture and promoting good air circulation across the crop.

Spray rotations of Chipco, Pageant or Heritage, Decree, Daconil, Dithane, Protect DF and drenches with thiophanate methyl and Medallion will help keep this pathogen at bay. Do not on apply Chipco on Spathiphyllum as it will cause phytotoxicity, apply Terraguard instead. Every day growers and researchers learn more and more about these strains of disease, more information will be shared as soon as it come to light!

References sourced:

• http://extension.psu.edu/plant-disease-factsheets/all-fact-sheets/cylindrocladium
• http://chasehorticulturalresearch.com/pages/ChaseArticles/17OrnamentalsAttackedbyCylindrocladiumSpecies.pdf