Integrated Plant Management (IPM) Defined
There are many definitions for IPM but they all seem to have a common thread: Problem Solving is: We are all problem solvers. We need to think of different ways to approach problems on the course. You can solve a problem with cultural practices, watering schedules, tree removal, or prediction models using growing degree-days. Each part of a solution improves the situation but using them together will give you the best results. The first thing you may think is to cut out chemicals and do everything biologically. That is not the case with IPM. IPM is simply a toolbox to draw from, and just one of those tools is chemical application.
Calculating Growing Degree-Days (GDD)
Calculating GDD can be a very simple process (Fig 1). This simple heat unit calculation can help you anticipate the development of insects and plants. For example, you can use GDD to anticipate when a particular insect becomes active after winter, when they begin to lay eggs, when the eggs hatch and when feeding begins. All these stages are very important to us from a management perspective.
The base temperature can vary depending on climate or target insect or plant. For our area in the mountains of Arizona, we used March 1st as a start date and use a base temperature of 50 degrees, give us the most accurate calculations.
Using Multiple Methods To Control Billbugs
We started out the winter by studying Billbugs. Our major question was: Where did they overwinter as adults? This was an integral part of our planning process because we were trying to decide where we were going to apply our contact application for maximum effectiveness. My assistant had some experience with Annual Bluegrass Weevils in the Northeast and he mentioned that they would remove all the leaf litter along the boundaries of the course. So we planned to target the perimeter of the course.
Method 1: We constructed and installed pitfall traps (Fig. 2 & 3). We picked the locations where we had substantial damage the previous year and placed the traps along the native to catch the adults as they came out from winter hibernation. Our plan was to use these traps in conjunction with the GDD data (Fig. 4) to make our adult application. We found this application to be very successful.
Method 2: We continued to accumulate GDD data for the next stage, which was larvae control. We studied how the Billbug larvae begin their lives in the stem of the plant. There are only a few days where they feed on the stem and crown of the plant before they make their way to the soil/thatch layer and begin the process of feeding on the roots and pupating into an adult. We knew the major damage occurs when they are above ground feeding on the crown of the plant so we needed to time our second application for that stage of life. Once the Degree-Days were close, we applied our systemic control product solely targeting the larvae feeding on the stem of the plant. This application proved to completely control the Billbugs for this season. We had no visible damage on the course from Billbugs.
Method 3: Our last method is cultural practices. Maintaining minimal thatch, adequate moisture, and complete nutrition makes the turf healthier. Cultural practices are like the gym for turf. They train the turf to become stronger and healthier to fend off the onslaught of insects and disease.
Integrated Plant Management is a dynamic part of our club that is constantly being amended. Each season we adapt to more problems that arise and we use the IPM format to create the best solution possible. We use our IPM program like a toolbox. We have many tools to help us accomplish one goal: To provide the best possible playing conditions for our members.