By DAN WHEAT
WENATCHEE, Wash. -- Washington apple growers may have to address diseases spreading to apples from crab apple trees used for pollinization to regain market access in China, an industry official says.
An important market of potential future growth, China cut off U.S. apples Aug. 9, saying it found post-harvest diseases that it wants kept out of its apple industry.
A Chinese delegation visited Washington packing houses in early December.
On Jan. 15, China proposed reopening the market if U.S. apples are incubated upon arrival in packing houses from orchards and if orchard sanitation steps are taken, said Mike Willett, vice president for scientific affairs of the Northwest Horticultural Council in Yakima.
Willett spoke Jan. 22 at North Central Washington Apple Day in Wenatchee. The meeting attended by several hundred growers was cosponsored by Washington State University and the North Central Washington Fieldmen's Association.
China's conditions have not been accepted, but the industry will try to propose some sort of new protocol that works, Willett told growers.
Contacted later, Todd Fryhover, president of the Washington Apple Commission, said this means China could remained closed for the remainder of the 2012-2013 sales season and maybe longer. It will take time, he said, for the board of Northwest Fruit Exporters in Yakima to decide if there are cost-effective protocols it can recommend to the USDA Animal Plant Health Inspection Service for negotiations with China.
In early December, Fryhover said China's allegations of post-harvest rot had not been proven and that the larger issue was China wanting market access in the U.S. for its Fuji apples. Now he said confirmation was suspect because China's fruit tracking is poor.
"Realistically, I think it's clear there is some post-harvest rot disease in Washington that needs some protocols to solve," he said.
Willett told growers that post-harvest fungicides will be a factor in stepped up quarantine inspections for China. Pruning crab apple trees and perhaps finding a replacement for the Manchurian crab apple pollinizer may be a solution, he said.
Speaking later, Tom Auvil, research horticulturist for the Washington Tree Fruit Research Commission, said the challenge in replacing the Manchurian would be finding another reliable early bloomer.
Manchurian crab apple trees appear very susceptible to twig die back and cankers caused by sphaeropsis fungus, Willett said. Research is under way to evaluate pre- and post-harvest fungicides to control sphaeropsis rot, Willett said.
"While pre-harvest materials work, I wouldn't want to rely on chemical controls. There needs to be other steps as well," he said.
Decay spread from crab apples could affect all varieties, Willett said.
Most interceptions in 2010 were for bull's eye rot, which was accentuated by high rainfall, he said. Speck rot and sphaeropsis rot are newer diseases that have been detected, he said.
China has previously accepted only U.S. Red and Golden Delicious but other U.S. varieties enter China from Hong Kong. Combined it amounted to 2.5 million, 40-pound boxes from the 2011 Washington crop and 2.9 million from the 2010 crop. So far this season, 1 million boxes have been sold to Hong Kong, but that is slowing and direct sales are nonexistent, Willett said.