Cranberry growers have all kinds of pests to deal with, and one of the toughest of those might be surprising to some people: the tundra swan. Tundra swans migrate to the area every year from Alaska and northwestern Canada and are particularly fond of red root, a weed that competes with cranberry vines for nutrients. When they fly in to feed, they not only tear out the red root, they also tear out vines and leave enormous holes that damage the beds themselves.
Since the swans are a protected species, growers have had to come up with a solution to keep them away from the crop. At Pine Island our PIICM team has been installing swan string for several years. The strings help keep the swans out of the bog by limiting the space available. “Swans are like a commercial airliner,” CEO Bill Haines says. “Having the strings up disrupts their attempt to both land and take off again.” Not all of the bogs are strung; our team maps them out where we have found red root and where the swans have been spotted. Just three acres of swan damage can give us a loss of 200 barrels per acre, or even more, depending on the variety. That takes three years to come back.
When setting up swan string, the team places rebar in the ground along the longer sides of a bog, about every 75 feet. On the ends of the bog, the team walks it out and determines how many lines they’ll need to run lengthwise though the center. Once the rods are laid out on the dam, a team of three to five people gets into the bog and walks the string across. Once the entire bog is strung, the team goes back in and puts up poles, which are used to keep the strings out of the water so that they don’t freeze. They’re placed in a checkered pattern, not necessarily on every line. The poles can either be cedar posts or recycled irrigation pipe. In addition to the recycling/environmental aspect, reusing the irrigation line is lighter and easier to handle.
Last year, we added a new method: an Agrilaser. From their website:
Deterring pest birds from open and semi-open spaces has long posed a costly and nagging challenge to property owners and managers. While noisemakers like propane cannons can scatter bird pests, they can also be disruptive and must be repeated often to keep birds from coming back. Lethal means of bird control—poisons, pellet guns and inhumane traps—are illegal in many areas, as many birds are protected by law. Bird B Gone’s Agrilaser® provides an effective, humane solution. It uses advanced, patented optical laser-beam technology to harmlessly repel pest birds over great distances—up to 2,000 meters. The handheld device is silent and completely portable. Pest birds react to the green beam as they would an approaching car, so they flee the area. Yet, unlike some deterrent devices, birds will not get used to the laser beam’s implied threat.
With some trial and error around timing and placement, our team found that it does have some effect.
This year, the team is again trying both methods! “Albert [Torres] has been going out and measuring the distances and putting stakes in ahead of the team,” says COO Bryan vonHahmann. “He’ll get the bogs staked out ahead of time, which makes it easier for when the rest of the crew comes. The crew has also streamlined their process over the years and have gotten much quicker; they’re doing a good job. We’re trying the laser treatment again this year as well. It’s going to be installed in the middle of farm, and we’re going to heavily monitor it. Our expectations are that it will keep that middle section ‘clean’, so we’re not trying string there at all.” He notes, however, that the team did find some beds with new swan damage during the growing season, and will be installing string in those locations. “What we really need to do is fix the root cause, which is red root,” he says. “But now we have Thierry [Besançon, the weed science specialist at the Rutgers extension] working on that. He’s been out here this year as we’ve been harvesting, trying to capture seedlings as they float from bog to bog, as well as experimenting with treatment applications and timing. Hopefully in next couple of years we can really start to attack it.”