IPM at work in county’s maintenance program
Large-scale roadside management programs can slip into a shotgun approach with predictable results–lots of power and noise, but, when the smoke clears, many of the targets are left standing. The problem often is that broad efforts with limited variation in techniques do not adequately address situations that may differ from one location to another.
Stephen Jones, the pest control adviser for the Alameda County (Calif.) Public Works Agency, is experienced with Integrated Pest Management (IPM), the use of an assortment of nest control weapons care fully selected and aimed to fit each specific circumstance.
His tools include mechanical, biological, chemical and cultural pest control techniques. Jones and a staff of nine county employees and 14 Conservation Corps crew members control pests along 1,000 miles of roadsides, 500 miles of flood control channels, 100 miles of railroad rights-of-way and on scores of vacant lots and landscaped areas.
“We will consider and use any and all pest control methods that are available, safe, economical and effective for a particular pest at any given site,” Jones says. “The bottom line is to consider what is best for each site individually.”
Jones has established a set of goals for each facet of his IPM program to prevent various control methods from being used haphazardly. For example, the goals for his roadside vegetation management program include:
* providing safe roads, including adequate sight distance around turns, non-hazardous traffic turnouts and water drainage;
* preventing fires in dry grass and brush while providing access for fire-fighters to nearby lands;
* maintaining the aesthetics of the sites; and
* protecting water quality by preventing roadside work from tainting adjacent waterways.
In California. flood control channels receive special attention, since water for human consumption can be scarce, and long, dry periods are often interrupted by torrential rains. In managing these channels, ]ones and the country work to ensure:
* control of undesirable plants;
* preservation of wildlife hahitat;
* safe access to facilities for maintenance employees;
* safe and efficient transport of stormwater to nearby San Francisco Bay and prevention of flooding; and
* water retention for replenishing groundwater tables and the municipal water supply.
With these goals in mind, the various control methods are considered for their appropriateness at any particular site. The first option is to do nothing and let nature take its course, but quite often that option is not practical. Flood control channels can become overgrown, for example, and roads can be broken up by plant roots.
“No matter what we do, nature will always have its way in the end, so we try to work with the site, not against it,” Jones says.
Traditionally, most roadside managers turn first to mechanical controls. Jones does use mechanical techniques, but he also takes into account their disadvantages.
“Our flail mower works well in some areas, but it’s not practical on most of our roadsides,” he says. Mowers, he notes, can start fires or throw debris that may break windows or cause injuries.
Non-traditional biocontrols, which pit one part of nature against another, have gained a growing role in Jones’ IPM program. In 1991, for example, when ash whiteflies were causing problems for homeowners living near flood channels, Jones obtained nursery trees that carried parasites deadly to the whiteflies. “We planted those trees, and the flies started dying off,” he says. “It was incredibly effective.”
Herhicides also play an important role in Jones’ program. “We consider the use of all herbicides that are available and appropriate for each site,” he says. “We use a wide variety of application equipment, from small hand sprayers to 1,000-gallon power sprayers.”
Preventing the growth of vegetation that could dry out and present a fire hazard is one of Jones’ main goals. But he is also concerned that pre-emergent, residual herbicides can move off site and damage nontarget vegetation, possibly contaminating surface water and groundwater in the process.
When off-site movement of pre-emergent herbicides is a possibility, post-emergent herbicides like Roundup, Garlon 3A, Garlon 4 and Weedar 64 are used.
Jones tank mixes two different herbicides with different modes of action to reduce the potential for weed resistance problems. For example, he sometimes mixes Karmex herbicide with Oust or Surflan herbicides. Jones further tailors his chemical pest control efforts to site conditions by using Rodeo herbicide along water ways, since it is labeled for aquatic use.
“Train your employees; read and understand the product labels and do the job right,” Jones advises. “Ultimately, it’s up to the applicator to decide which plants to spray and which to not spray.
“And keep the spray where it’s intended to go. For example, when we treat our roadsides, we avoid spraying onto mailboxes, bus stops and private property.
“Share information about your spray program with the public, so that they understand what you’re doing and why,” he says. “[For example], when we spray near a sensitive site like a school, I call the school in advance so there are no children along the fence when we spray. By calling ahead, we build trust and make people feel that they are a part of the process.”
Cultural controls are another key aspect of the county’s IPM program. For instance, there are three inflatable dams on Alameda Creek, and when the water level is raised or lowered, the change in conditions prevents much of the unwanted vegetation from growing.
Cultural controls like planting perennial grasses and other desirable plant species and mulching are also viable options for controlling unwanted vegetation on many sites in the county.
Establishing an efficient, effective IPM program is not necessarily easy. “We still have to monitor our sites and adjust to get the best results,” Jones says. “There is no magic bullet — just hard work.”