Issue link: https://read.dmtmag.com/i/450509
34 FEBRUARY 1, 2015 Good Fruit Grower www.goodfruit.com S cientists in New Zealand have planted a prototype of a "super orchard" that they hope will produce up to twice as many apples as a typical productive orchard. Dr. Stuart Tustin, a plant physiologist and science group leader at the Institute of Plant and Food Research in New Zealand, said he and his colleagues are working to fi nd out what the biological limit of an orchard is, in terms of production, and to identify factors that prevent growers from achieving that. Tustin, who spoke during the Washington State Horticultural Association's annual meeting, said pro- ductivity is infl uenced by two factors: the amount of light intercepted by the tree, which fuels photosynthesis, and how the tree allocates resources between its vari- ous parts and functions. Research has shown that in current orchards, yields increase as light intercep- tion increases. But beyond 60 to 75 per- cent light interception, the relationship falls apart. "In my research experience, and measuring light interception in highly productive orchards, the highest I've Taking yields to New Zealand scientists have planted a prototype 'super orchard' they hope will produce around 170 apple bins per acre. by Geraldine Warner THE LIMIT Trees are planted 10 feet apart. Each tree has 10 upright shoots, or stems, trained from the cordons every 12 inches. Rows are planted 5 to 6 feet apart. Stems can grow up to 11.5 feet. Yields theoretically could range from 150 to 200 bins per acre. (U.S. apple production currently averages around 35 bins per acre.) To grow a 'super orchard' Apple trees could theoretically yield more than 150 bins per acre, says New Zealand scientist Dr. Stuart Tustin, but it would require a complete orchard redesign. SOURCE: NEW ZEALAND INSTITUTE FOR PLANT & FOOD RESEARCH LIMITED JARED JOHNSON/GOOD FRUIT GROWER ILLUSTRATION Horticulture PLAY Stuart Tustin explains how improving orchard structures can increase yield. www.goodfruit.com/media Washington State Horticultural Association's annual meeting, said pro- THE LIMIT PLAY Stuart Tustin explains how improving orchard structures can increase yield. www.goodfruit.com/media ever measured is in the 60 to 65 percent range," Tustin said. "And getting above that is rather challenging." Dr. John Palmer, plant physiologist with Plant and Food Research, has extrapolated from the systems that he's measured that at 90 percent light inter- ception, yields could theoretically be in the range of 150 to 200 bins per acre. In comparison, Washington's cur- rent average yield is 48 bins per acre, according to agricultural economist Dr.