Mixing it up

The best maintenance practices promote healthy turf, but natural conditions can threaten even the sturdiest stand of grass quickly. The combination of hot temperatures and humid air can set up the perfect medium for an outbreak of pathogens. Warm soils can lead to proliferating pests, and even cool winter weather can promote threats of damaging molds.

Spraying pesticides takes away time from other cosmetic projects, so tank mixing can help make applications more efficient.

When these conditions appear, it’s imperative a superintendent recognize them and dip into his arsenal of pesticides to combat their threats.

Pesticides normally are applied with spray tanks of varying sizes, some of which can hold as much as 300 gallons of solution. The spraying of tees, greens and fairways can impact golfers negatively, so developing an effective method of spraying is important to deliver agents efficiently and to limit the impact on golfers. One way to increase spraying efficiency is to blend several agents that can then be applied simultaneously. However, there are certain precautions that should be considered when mixing different pesticides.

Quent Baria, superintendent at Towson Golf & Country Club in Phoenix, Md., gets put to the test every summer by the effects of heat and humidity.

“We get into periods here where I will spray my tees and greens every seven to 10 days and the fairways every two weeks,” he says. “We usually spray three days out of seven, so combining chemicals to get more bang for the buck is a necessity.”

Compatibility
Baria calls a pesticide mix “witches brew” because as many as nine different chemicals might be mixed. But the creation of these formulas isn’t the result of trial and error. It takes careful balancing of agents to create a mixture that will perform correctly.

Pesticide mixing should be done outside on a dedicated concrete pad that will catch any spills.

The first step to develop a blend of pesticides is to read the labels to learn the chemical nature of each pesticide, determine its application rate and understand the safety precautions for each.

“Reading the labels is a critical step,” Baria says. “It’s also federal law for anyone who handles these agents.”

Once a formula is created, it’s wise to perform a jar test of the mixture. This consists of making a sample of the formula in its proportions in a quart jar, shaking it completely and letting it set for at least a half an hour to observe the result. Two forms of compatibility, physical and chemical, can be determined by conducting a jar test.

Physical compatibility refers to the ability of the agents mixed to blend together into a liquid that will spray easily. An incompatible mix can become a glutinous mass that won’t spray well and can cause delicate machinery to become clogged or damaged, which can lead to expensive repairs and downtime. Some agents might not dissolve properly and precipitate out, which hinders their rate of effectiveness. This can lead to a futile application that can be a waste of expensive products and manpower.

The second form is chemical compatibility. Mixtures need to be created in the proper amount and order so they don’t create a new chemistry. An improper mixture can weaken an agent’s effect or change into a phytotoxic mixture that can damage the turf. Even the simplest mistake can lead to expensive mishaps.

Should the jar test show bad results, a new mix can be created by adjusting the formula or adding adjuvants to help the ingredients mix with water. Other additives, i.e., surfactants, can be added to help the mixture disperse as water droplets during the spray application. The stakes are high when dealing with chemical agents, so getting opinions from other superintendents in the area is another way to avoid disaster.

“This is one area of our profession where superintendents want to share information,” Baria says. “Finding suggestions and learning about other superintendents’ experiences is important. This is one area where a mistake can be very costly. This isn’t a task where experimentation comes into play.”

There are several other factors that should be checked when mixing pesticides. The water that’s used for the mixing should be tested because high levels of salts, iron or magnesium can change the chemistry. The pH level should be checked because many municipal water sources have a wide range. A pH level of 6.0 or below generally will keep tank mixtures stable.

“I found it crucial to keep abreast of the pH level in my water,” says John Burke of Westfields Golf Club in Clifton, Va. “I only mix two agents at a time, but I add buffers to the mixture to control the pH.”

Mixing pesticides should be done outside on a dedicated concrete pad that will catch any spills. The tank should be filled about half way with water and then agitated before adding chemicals in their proper order as prescribed on the labels for each agent.

How much to mix
The number of agents mixed by superintendents varies considerably. Most will mix two agents at a time, usually combining a fertilizer with a fungicide to create a preventive mix to control pathogen outbreaks such as pythium and brown patch. Others will push the envelope by mixing five or six agents to apply them in one spray session.

James “Hud” Haas, superintendent at The Links at Waterchase, an 18-hole course in Fort Worth, Texas that opened in 2000, has been at the course since the grow-in phase and reduced his budget 22 percent since then.

“I’ve found many ways to squeeze out a bit more to control costs,” he says. “The cost of chemical agents is substantial, and you can’t save money by diluting the products. Therefore, I look past certain issues the average golfer won’t be bothered by. We’re always working right on the edge, but you want to limit your applications to not impact the golfers.”

Spraying takes away time from other cosmetic projects, so mixing can make for a more efficient application. Haas’ course is planted with ultradwarf Bermudagrass, which is more disease resistant. His mixing involves fertilizer and a fungicide or an insecticide to control cut worms, army worms and Bermudagrass mites.

“It’s important to know the makeup of your fertilizer,” he says. “The phosphorous level can have a major effect when mixing, so I always do a jar test when I use a new product.”

Keeping track
When tank mixing pesticides, keeping complete documentation is important. In many states, it’s a requirement to keep records of pesticide use. Also, documentation is an excellent way to keep a record of different chemical mixes for future reference.

Peter Schmidt, superintendent at the 27-hole Shenandoah Golf Club in Front Royal, Va., finds himself in a difficult two-month window during the summer and documents the mixes he uses, the weather conditions when he sprays and the results of his applications.

“Keeping track of all these factors keeps me in compliance but also helps me determine what has worked well for me in the past,” he says. “You don’t get second chances when you make a mistake with these agents, so having the documentation as a reference is crucial.”

Schmidt’s records also help determine how many pesticides to mix at a time. This is important because all of the mixed solution should be applied on the turf, and nothing should be left over. Federal regulations state superintendents can do two things with chemical agents: apply them and store them. Disposal can be costly, and in many cases illegal, so using all of the chemicals that are mixed is critical.

“After application of some materials, I’ll rinse the tank, but I’ll spray that rinsate out in the rough areas of the course,” Schmidt says.

Schmidt also has mixed six agents at a time.

“I’m a believer in the old joke that you can’t mix 10 items at once,” he quips. GCN

Doug Saunders is a freelancer writer based in Truckee, Calif. He can be reached at dougs@sierra.net.