Issue link: https://read.dmtmag.com/i/787641
www.goodfruit.com GOOD FRUIT GROWER FEBRUARY 15, 2017 23 TJ MULLINAX/GOOD FRUIT GROWER These acclimation hoop tunnels inside the greenhouse control temperature, humidity and light density for the tiny plants. Depending on the crop, plants are acclimated here for three to fi ve weeks and then moved to the growing greenhouse. Workers then root the plants, some in the lab and some in the greenhouse, depending on the crop, before moving them to acclimation hoops, where the tempera- ture, humidity and light density are carefully controlled. "These three factors have to be under control, otherwise, in 5 minutes, with these small cuttings, they can stop growing," Chang said. "They can shut down quickly." The acclimation process generally takes three to fi ve weeks, depending on the crop, before the plants are moved to the growing greenhouse to grow bigger for shipment. Last year, North American Plants sent 8 million plants to customers in April, May and June alone. The company supplies to nearly all of the major nurseries in the U.S. from its base in Oregon's Willamette Valley — apples, pears, cherries, peaches and nectarines, as well as avoca- dos and nuts to meet demand in California. It employs as many as 170 full-time workers in the busy spring months. For apples, Chang only produces the fi re blight-re- sistant Geneva rootstocks, which "for sure have a great future, but it's such a rush to get them out. It's so quick, it's dangerous," he said. "Some people are planting the same age of trees as the rootstock trial. They are really good rootstocks, but we still have a lot of things to learn." One of the more challenging rootstocks in liner beds — Geneva 41 — remains tricky to propagate through tissue culture, and takes much more work to produce. While many rootstocks can multiply at a 1-to-3 ratio, G.41 is probably closer to 1-to-2.5. Pushing that rate increases the risk for mutations. "There isn't any lab that can 100 percent guarantee plants without mutations, but we can control for that," he said. "We do everything possible — from media rec- ipe, culture environment, anything that could sync up back to mutation — to try to reduce the chance." Tips for growers Several large orchard companies have turned to tissue culture labs to get access to fi re blight-resistant rootstocks, Auvil said. He encourages others to consider it, with care. "They're sensitive to drought, too much sun, too much cold, too much wind. But mostly, it's water," he said. "The No. 1 issue is getting water to the tree." Moving the trees from a greenhouse to direct fi eld conditions without adequate irrigation can drought- stress the plants, causing margin burns on leaves or dropped leaves, until the trees are able to establish their root system. Some people are more careful the fi rst year and won't make any mistakes, Chang said. "But normally, after one year, everybody can learn." • PLAY Learn about North American Plants' process from Yongjian Chang and see more from our interview: goodfruit.com/media GAME CHANGERS Budded to your cultivar selection Actively growing scion Ready in as little as 3 months from order to orchard One-year budded tree Spring Budded to your cultivar selection Replaces a conventional bench-graft with a premium rooted tree You plant 100% of the tree's roots Quick turn - in as little as 3 months, instead of 2 years Eliminates transplant shock (crucial for Geneva® 41 & Pears) Tested and proven on millions of orchard trees! Call Tree Connection at 1.800.421.4001 The Ellepot™ PRODUCT LINE UP: Quick-Start Ellepot™ apples CHERRIES PEARS MODERNIZING ORCHARD DEVELOPMENT WITH OUR ELLEPOT™ SYSTEM OF FINISHED CONTAINERIZED TREES. Spring Budded Ellepot™ Geneva® Series M-9 Series Bud 9 & Bud 10 Gislea® Series Krymsk® Series OHXF Series Pyro™ 2-33