Category Archives: Plants

Managing Difficult Plant Diseases

Photo © Ken Chamberlain. Photo courtesy Ohio State University

By James Chatfield, Joseph Boggs, and Erik Draper

Turf professionals often speak about why plant diseases are so difficult to manage. They generally note some key challenges, including how the inoculum of plant pathogens is microscopic and how they do not see the pathogen arrive on a plant, germinate, penetrate, and infect it. By the time visible symptoms develop, it is too late to prevent the invisible (to the naked eye) infection that has already occurred days, weeks, or months earlier.

Secondly, disease control is almost totally preventative, not reactive. For true prevention, turf managers should choose species or cultivars with genetic resistance to disease or planted into situations where disease is less likely to develop.

Another challenge involves anticipating how bad rose black spot or apple scab, for example, will be in a given year, depending on how well turf professionals can predict the weather.

Further complicating matters is that pathogens change. This means while horticulturists busily go about breeding for genetic resistance to a particular disease, nature works 24/7 via mutations and natural selection. The resulting new strains of the pathogen, such as the Venturia inaequalis apple scab fungus in Ohio that overcomes the genetic resistance of ‘Prairifire’ crabapple, can be difficult to predict.

A final challenge is dealing with numerous host plants, which is especially difficult for the green industry since there are hundreds of genera of ornamental plants, each with their own particular set of diseases.

Read the full article: Managing Difficult Plant Diseases