Issue link: https://read.dmtmag.com/i/629538
32 FEBRUARY 1, 2016 GOOD FRUIT GROWER www.goodfruit.com Malling 9 T-337: M9.337 is the global standard for rootstock and is the most widely planted cultivar in Washington. M9.337 shows tremendous compatibility with most scions, but its susceptibility to fire blight makes it a rootstock to avoid in areas where fire blight is a concern, Auvil said. Also worth avoiding: pairing M9.337 with fire blight susceptible scions that bloom early and for a long time, such as Cripps Pink and Jazz. Geneva 11: G.11 can be disappointing in its vigor, particularly in sandy or light soils. In good soils, G.11 grows very vig- orously on nonbearing trees and grows large fruit. The rootstock seems to do well in nurseries, and some plantings back East have reached 25 years old and are still going strong, Fazio said. G.11 is not resistant to all the strains of fire blight, but compared to M.9, it's resistant. "You'll lose maybe a tree as opposed to a whole orchard," he said. Geneva 16: Two words: virus sensitive. Even with certified wood. "We've had blocks that have had sustained tree losses over time. It's relatively slow, but even a half a percent adds up over time," Auvil said. "It can take three to four years from first symptom to final end," he said. Fazio called G.16 one of the wonders that made beautiful, productive trees in the nursery. It's still being used in the Southeast U.S. and in Minnesota's breeding program, he said, but clean wood is essential. Malling 9 Nic29: This is the largest M.9 used in the West, but some nurs- eries have removed it from production due to its susceptibility to fire blight and replant disease. The rootstock tends to remain very vigorous, but works well with slow-growing scions. However, that vigor can create a late bloom, adding to those fire blight concerns. Malling 9 Pajam2: More vigorous than M.9, Pajam2 is productive with large fruit. Replant may be a bit of a problem, and fire blight is also an issue. A clone of the original M.9, this rootstock has similar characteristics of M.9 Nic29. Malling 9 EMLA: EMLA 9 tolerates most soil types, except dry, light soils in low rainfall areas. Its root systems tend to be a little more fragile, so take care when digging up or planting this cultivar, and it's susceptible to fire blight. It also has similar characteristics to M.9 Nic29, but it's been cleared of viruses. Geneva 935: Another high-performing Geneva rootstock, G.935 is a good rootstock for weaker varieties, such as Honeycrisp, with good fruit production. It's tolerant of replant disease, but not woolly aphid resistant, and is commercially available. Geneva 969: G.969 has not been eval- uated in the Northwest, though it's the easiest to grow in a nursery of the entire Geneva family. In the East, it's rated a very large tree and a high-performing tree. G.969 is the only cultivar in the Geneva family that stands up when it grows, rather than bend over like a rasp- berry bush. Fazio said G.969 will make weaker varieties shine. It is commercially available in limited quantities.