Orange growers turning toward biological pest control
By Urban C. Lehner
DTN Ag Services Editor-in-Chief
LINDSAY, Calif. (DTN)--It's a snail-eat-snail world here in the orange groves of California's San Joaquin Valley.
European brown snails, which gourmet restaurants serve drenched in garlic butter as escargots, are preying on California's citrus crops. In self-defense, the orange growers set loose decollates, a smaller snail that nonetheless devours the larger, faster European brown. It's a form of biological control California producers are using to combat a variety of pests as the political climate of this politically correct states turns increasingly against pesticides.
The orange growers face no shortage of pests to combat. Katydids take bites out of the orange rinds, which don't damage the fruit inside but render the orange unpresentable in grocery stores. Citrus thrips scar the oranges. Citrus red scale will kill the trees if not checked. Citricola scale and cottony cushion give rise to sooty mold.
Charles Fisher, who farms 800 acres in Lindsay, much of it orange groves, shows visitors a statement he received recently from Sierra Citrus Association, the co-op that packs his fruit. The statement had good news--about 72 percent of the oranges from one of his blocks were packed as the highest grade.
But the comments at the bottom of the sheet recited a litany of woes: "Light peel miner; medium injuries; medium katydid scars; medium sunburn; medium thrip mark; medium end checks; light wind damage; light coarse texture; light snail damage."
And that's after spending $300 to $400 an acre, roughly a third of his costs, on pesticides.
The snail damage would have been worse than "light" had it not been for the decollates, which eat at least some of the European browns.
"Now what happens when they've eaten the rest of them (the European browns), I don't know," Fisher said. It doesn't seem likely to happen anytime soon.
But biological controls are only a partial answer and while they solve some problems, they sometimes create others, in some cases allowing long- eradicated pests like citricola scale to return.
Fisher went into the orange business in 1978 though his father warned him that "only idiots and fools grow oranges." Before oranges Fisher had tried cotton but decided it was a "poverty weed."
He concentrates on navel oranges. Valencia oranges, featured in orange juice, have lost popularity. Some blame the Atkins diet, which discourages OJ. As the tour bus passes a vacant plot, Fisher--a balding, mustachioed man with a twinkle in his eye--describes the plot as a "Valencia grove that bit the dust--it had bulldozer blight."
He also grows olives but complains that "economically, olives are the pits." Imports from Spain take 40 percent of the market, he said, and drove down prices $400 a ton last years. He also grows wine grapes--columbard, muscat and cabernet sauvignon--but bemoans the environmental regulations, which will prevent him from burning old vines altogether starting in 2010.
Fisher said his biggest problem are environmentalists and pesticide rules.
"It's going to get to where we can't even spray," he said. "Then I don't know what we're going to do."