Turf Pest Management Category 3B Practice Test

Nitrogen timing affects how fast and how much the turf grows, which in turn changes tissue quality and the microclimate in the leaf canopy. When nitrogen is applied in excess or late in the growing season, the turf puts on lush, rapid growth with softer, more succulent leaves. This dense, high-moisture canopy tends to stay wet longer and shade the soil, creating ideal conditions for many diseases and making the turf more attractive to pests that feed on tender tissue.

In contrast, applying nitrogen in a balanced, species-appropriate way supports steady growth, stronger root systems, and tougher leaf tissue, reducing the likelihood of disease outbreaks and pest problems. Early nitrogen can aid establishment, but it isn’t inherently the best approach for minimizing disease risk if it leads to late-season flushes or over-fertilization.

So, the timing that most increases disease and pest susceptibility is when nitrogen is excessive or applied late, because it promotes lush growth that creates favorable conditions for pathogens and pests.