Which factor is NOT important to consider when diagnosing disease in turf grasses?

When diagnosing diseases in turf grasses, the seed germination rate is not typically a critical factor to consider. While a low germination rate might indicate problems with the seed quality or the initial establishment of the grass, it does not directly relate to ongoing disease diagnosis in established turf.

On the other hand, factors such as blade sharpness, soil pH and fertilizer, and weather conditions are essential in diagnosing turf grass diseases. Sharpness of mowing blades, for instance, can influence the overall health of the grass and its vulnerability to pathogens. Soil pH affects nutrient availability and can influence grass health, while weather conditions, like humidity and temperature, can significantly impact disease development and prevalence. Thus, while seed germination may be relevant in the context of establishing turf, it does not play a direct role in diagnosing diseases once the grass is established.