Issue link: http://read.dmtmag.com/i/114539
Pollination What could REPLACE Manchurian? S cientists are recommending that the Washington apple industry look for alternatives to Manchurian crab, the predominant pollinizer, because it is a host of fungal pathogens of quarantine concern. Trouble is, no studies have been done in the past 30 years to find other pollinizers that would fit the industry's needs. Ken Adams, president of Willow Drive Nursery in Ephrata, Washington, said that before the 1980s, when most of the apples grown in Washington were Red and Golden Delicious, growers used to plant four rows of Reds and two of Goldens so that the two varieties could pollinate each other. Then, when growers began planting Granny Smith, Fuji, Gala, and other new varieties, they recognized the need to use pollinizers. This also enabled them to plant solid blocks of a single variety, making them more efficient to harvest. Manchurian crab has been the most popular pollinizer because it blooms very by Geraldine Warner early—in time to pollinate king bloom of Red Delicious. The timing is also good for most of the other major varieties grown in Washington, such as Fuji, Gala, and Granny Smith. Snowdrift, which blooms about seven days later, is also widely planted to pollinate later-blooming varieties. Adams said Willow Drive also sells smaller quantities of Indian Summer, Mont Blanc, and Evereste. "Manchurian has been the workhorse. I'm not sure there's one that could really replace it," Adams said. "People don't want to go back to the four rows of Reds and two rows of Golden Delicious. Solid blocks are so much more efficient, and you're dealing with one crop. If they lose Manchurian, it's going to be an issue." Many crab apples are available, but most are grown as ornamental trees. Specific needs Ornamental nurseries sell a wide variety of crab apples, but the tree fruit industry has specific needs, said Tom Auvil, research horticulturist with the Washington Tree Fruit Research Commission. The pollinizer must bloom early enough to coincide with the earliest-blooming apple varieties, and it should have a tall, upright growth habit so it catches the bees as they fly over the tops of the trees. It should have white or pale pink flowers, which appear to be more attractive to bees than red blossoms. This Gala orchard has the late-blooming Indian Summer pollinizers (in the foreground) and the earlier Manchurian (in the background). 22 March 15, 2013 GOOD FRUIT GROWER www.goodfruit.com