Turf Toughie: Biotic vs abiotic turf problems

Hang around in a class with Jim Kerns, assistant professor and extension specialist in plant pathology, and one question you are sure to get is: What are the factors that distinguish a biotic turf problem from an abiotic turf problem?

Students at North Carolina State University and Super Science readers who want to score an “A” had better list at least five factors. Take a second to write down your answer. Review it. In fact, that is another thing Kern tells students – consider everything before responding.

Here are five clues to distinguish pathogen-caused problems from mechanical or other problems:

1. Diseases are progressive, starting slowly and increasing in scope. Mechanical damage is instant.
2. Look at the symptoms. Diseases will have a transition from sickly to healthy plants.
3. Is there a pattern? Diseases are random but mechanical damage often shows a pattern.
4. In a mixed stand, usually just one variety will be declining from a disease problem. Other varieties probably will not be affected. Mechanical damage hurts all plants.
5. Lastly, most weeds found along fairways are resistant to disease, often expanding quickly into areas killed by something like take-all. Again, mechanical damage hurts all plants.