2011 Highlights: UC IPM Annual Report

UC Davis professor and extension specialist Frank Zalom monitors for peach twig borer. Photo by J. K. Clark.

Australian market opens—temporarily—for nonfumigated IPM-managed fruit

UC researchers recently proved to Australian regulators that an IPM approach to managing peach twig borer in stone fruit crops could successfully eliminate the pest from California fresh fruit shipments, enabling Australians to drop the requirement that such fruits be fumigated.

In the 2009 and 2010 growing seasons, Walter J. Bentley, UC Cooperative Extension farm advisor and IPM advisor, and research assistant Andrew Molinar, demonstrated that growers could keep peach twig borers out of harvested fruit when they used a season-long IPM program for managing this pest.

But the California arrival of a new pest, spotted wing drosophila, has spoiled the good news.

“Exotic pests that can move around the world are a big problem,” Bentley said. “Growers begin applying great IPM programs that solve our pest problems really well, then a new pest comes in and disrupts the whole system.

“Unfortunately, we still have to fumigate California’s fresh stone fruit shipments if we want Australia to accept them. They understandably don’t want to risk import and establishment of spotted wing drosophila.”

Spotted wing drosophila showed up in the Western United States in 2008 and has since been found throughout California. Growers have seen significant damage to caneberry, cherry, and strawberry crops, although to date no commercial peaches or nectarines have been infested. However, both crops are listed as potential hosts, and this is the cause for Australian concern.

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