Mighty mow

Bob Brewer calls it a “Bobcat on steroids with a big dental problem.” Dan McCarthy calls it a blessing. It’s a 100-horsepower skid steer machine—a cross between a bulldozer and a Bobcat—that can mow down tall orchard regrowth –leaving nothing but a few small twigs.

Brewer, who operates one of the machines for its owner, J.W. Crenshaw of Omak, Washington, has used the machine extensively in forests for thinning out small trees after fires. It can grind up trees as big as 12 inches in –diameter.

McCarthy, fieldman for the Okanogan County Horticultural Pest and Disease Board, has the job of keeping an eye out for pest situations that could threaten the commercial tree fruit industry. He thought the machine might have potential for removing troublesome regrowth in former orchards that can harbor pests when it grows big enough to fruit.

So this summer, the pest board hired Brewer to clear the substantial regrowth in parts of a 55-acre repossessed orchard near Tonasket, where large Red and Golden Delicious trees were removed six or seven years ago. The site hadn’t been mowed in three years, and the seedling roots had put out tall, bushy growth. The pest board has court authority to maintain proper pest control for the Farm Services Agency, which –currently owns the orchard.

This was the first time Brewer had cleared orchard regrowth. It took about 37 hours to mow 55 acres, at a cost of $115 per hour (an average of $77 per acre). However, 25 acres were light brush that didn’t take as long to mow as the stronger growth. The regrowth is removed at the ground, along with weeds, leaving no residue or chips to remove.

McCarthy estimates that there are about 500 acres of former orchard in the county that are “in limbo”—neither being farmed nor developed—and have the potential for regrowth. And he sees the skid steer as a quick and affordable way to deal with it.

“For this particular application, this is the perfect tool,” he said.

When growers remove orchards, it is best to mow the regrowth regularly so it doesn’t become too large to be mowed with orchard equipment, as happened in this case, said McCarthy. When it reaches that point, it can’t be ploughed, either, until the growth is removed. Regrowth is less of a problem where the trees were on dwarfing rootstocks.

Ideally, former orchard land should be cultivated and planted to an alternative crop, such as hay, or converted into pasture. However, a herd of goats has successfully kept the regrowth down in one former orchard near Tonasket.

In limbo

McCarthy said there might have been more problems with neglected orchards if it were not for the fact that apple and pear growers are optimistic that fruit prices will be good this year. “A lot of marginal orchards are being leased and farmed properly,” he said.

But not all. Though most property owners can be persuaded to either spray the trees or remove the orchards, some do neither. McCarthy recently took a case to court, for the first time in about five years.

The case concerned a two-acre d’Anjou pear orchard that last produced a commercial crop in 2000 and was no longer being sprayed or irrigated. However, spring snowmelt and rain provide enough moisture to keep the trees alive.

The site is within 150 yards of another commercial orchard. While codling moth is the usual reason for taking action over an unsprayed orchard, this one didn’t have the pest because it had no fruit, McCarthy said. The trees are so infested with pear psylla that the fruit falls off. Eventually, the leaves drop, too. The wood is black with sooty mold. The court ordered the owner to remove the trees.