Good Fruit Grower

July 1

Issue link:

Contents of this Issue


Page 16 of 47

Delayed sunburn shows up late Granny Smith apples D yellowed from delayed sunburn sell for half the price. by Melissa Hansen elayed sunburn in apples starts out as a pre- harvest issue, but because it doesn't appear until fruit have been in cold storage for several months, it's also a postharvest problem. Delayed sunburn can have a major economic impact on packouts, reducing fruit quality from what started as the top grade to a lower grade, while also reducing f.o.b. prices. The Washington Tree Fruit Research Commission has studied delayed sunburn on Granny Smith to identify the problem and explore measures to minimize sunburn in the field. Dr. Ines Hanrahan, project manager for the Research Commission, shared her research results dur- ing a spring postharvest meeting sponsored by Pace International and held in Ellensburg, Washington. Delayed sunburn, not to be confused with normal sunburn or sunscald, comes in two types: previously undamaged fruit (fruit appeared clean when put in cold storage) and fruit with a small amount of sunburn damage at harvest, appearing as slight yellowing. "With delayed sunburn, you can have bins of Granny Smith that look pretty good at harvest, maybe some fruit Apple on right is an example of the appearance of yellow hues and bleaching of Granny Smith apples after four months in regular-atmosphere storage during the 2011-2012 storage season. The fruit was an even green color at harvest (as shown on the left). with slight yellowing or blush, but overall pretty clean," Hanrahan said. "But then you pull them out of storage three to four months later and that's not the fruit you remember. The clean fruit are now slightly yellow—or worse, are dark brown or black. Or fruit that were only slightly yellow at harvest are now much worse." KEEP DEER OUT! GUARANTEED! KEEP DEER OUT for as little as $135 an acre Deer Shield harnesses of natural deer to effectively repel recordings of actual deer distress and alert calls are used to trigger an instinctive flee response. Deer soon relocate to where they can feed without feeling threatened. communications them. Digital No Fences No Nets No Deer No Birds the power Organic Humane No Sprays Bird Gard uses the language and natural instincts of birds to effectively repel them. Digital and alarmed birds, along with the sounds of their natural predators trigger a primal fear and flee response. recordings of distressed, Bird Gard protects millions of crop acres worldwide IF YOU ARE NOT COMPLETELY SATISFIED WITH THE RESULTS SIMPLY RETURN IT FOR A FULL REFUND OF YOUR PURCHASE PRICE. TRY ANY BIRD GARD OR DEER SHIELD PRODUCT FOR AN ENTIRE YEAR. Electronic Deer Control from the makers of injured KEEP BIRDS OUT for as little as $116 an acre In tracking one lot of Granny Smith apples from har- vest through six months of storage, Hanrahan found that half of the fruit was clean at harvest, and though it had been treated in the field with a sunscreen protectant, from 18 to 35 percent of the clean fruit turned yellow during storage. KEEP BIRDS OUT! 888-332-2328 The World Leader in Electronic Bird Control GOOD FRUIT GROWER JULY 2012 17 photo by Ines hanrahan, WtFrC

Articles in this issue

Links on this page

Archives of this issue

view archives of Good Fruit Grower - July 1