Turf MD: Are golf courses really using too many pesticides?

Spring is a time of considerable agronomic activity that corresponds with the general population’s interest in their own landscapes. At this time, the most common question I get as I walk through my neighborhood — besides what is wrong with my lawn — is about pesticides.

The popularity of this question seems to ebb and flow, ranging from real concerns throughout the 1990s to a much lesser extent now. Elsewhere in the world, however, banning pesticides, especially on golf courses, has either occurred or grown in Europe and South America.

One of the more popular comments directed toward me is, “Why do we use more pesticides now than we used to?” To answer that question broadly, I agree that we are using more pesticides than we used to. Although the phrase more than we used to is a little too vague.

Golf’s first pest

In the early to mid-19th century, few, if any, golf course pests existed and links courses in the United Kingdom were essentially the exclusive hosts of the game on the planet.

At the time, the location and climate were ideal for that rudimentary version of golf. In the early 1850s, as course construction became more popular inland, golf went through its first major boom. With those new courses came new struggles, as poor-draining clay soils brought along earthworms.

Earthworm infestations, and the resulting earthworm casts, made putting greens unplayable for most of the year. As a result, golf failed miserably, with earthworms being a major contributor. One could argue that earthworms were the first golf course pest.

During this period, however, scientists identified compounds to act as both an irritant for earthworms, causing them to emerge at the surface where they could be physically removed by workers, or a toxin.

A broader spectrum

Pesticides developed or used from the early 1900s to 1960s were primarily inorganic materials known for being toxic to many things — humans included — such as arsenic, cadmium, copper, lead, mercury, nicotine and sulfur.

Additionally, these products were nonbiodegradable, applied at high rates and many had broad spectrum uses. In this case, the term broad spectrum takes on a different meaning than what we would use in modern times.

For example, Paris green, a copper-based arsenate product developed in 1814 by two German scientists, was once used to kill rats in Paris sewers. By the 1880s, it was the most widely-used insecticide in the world. Later in 1945, Italy used the product to control the spread of malaria.

Continued development

Since the 1960s, scientists have developed lower-risk biodegradable pesticides characterized by short residuals, low application rates and targeted specific pests. Due to the development of these newer pesticides, many older inorganic herbicides have seen a drastic drop in use.

In the 1980s, the Environmental Protection Agency (EPA) banned arsenates like lead and others. Years later, in the ’90s, the EPA banned the last mercury-based product Calo-Clor, traditionally used for snow mold.

Looking back to when some say we used fewer pesticides than we do now provides a perspective of how much pesticides have evolved. We need to quantify the use of new, lower environmental risk products within a pest control program. Maybe developing a score that reflects the risk of your program can justify its use.

Karl Danneberger, Ph.D

Karl Danneberger, Ph.D., Golfdom‘s science editor and a professor at The Ohio State University, can be reached at danneberger.1@osu.edu.