Location: Southern Horticultural ResearchTitle: Potential of spreading binucleate Rhizoctonia from nursery propagation floors to trays containing azalea stem cuttings
Submitted to: Ornamental Workshop on Diseases and Insects
Publication Type: Abstract Only
Publication Acceptance Date: 9/25/2014
Publication Date: 9/30/2014
Citation: Copes, W.E. 2014. Potential of spreading binucleate Rhizoctonia from nursery propagation floors to trays containing azalea stem cuttings. Ornamental Workshop on Diseases and Insects. 1.
Technical Abstract: Binucleate Rhizoctonia fungi cause web blight on azaleas and other woody ornamental plants. This research focused on one aspect of how the pathogen may spread from contaminated floors of propagation houses into trays containing clean azalea stem cuttings that generate new root systems. Rhizoctonia was recovered on average from 14% of floor surfaces. The pathogen naturally declined to a smaller population level over the 6 weeks houses were empty between crops. If floor surfaces are cleaned of organic matter, the risk of the pathogen growing from the floor into rooting trays appears low. Disinfestants can eliminate the pathogen on ground fabric floors. On gravel floors, disinfestants cause a significant decrease but may not eliminate the pathogen. Combined with other sanitation methods the prospective looks favorable for producing azaleas free of binucleate Rhizoctonia. This information will benefit cooperative extension specialists and businesses that produce azaleas and other woody ornamental plants that get Rhizoctonia web blight.