Issue link: http://read.dmtmag.com/i/37334
Harvest/Postharvest Harvest quality parameters for Gala, WA 2, and WA 5 Gala apples were grown near Vantage, Washington, and picked at first commercial pick. WA 2 and WA 5 were grown in an orchard near Quincy, Washington, on fourth-growing-season trees. Gala/Vantage Aug. 27 Firmness (pounds) Diameter (inches) Weight (grams) Color (1-5) Starch (1-5) Sugar (Brix) Acid (percent malic acid) 20.1 3.2 247.0 5.0 3.0 11.4 0.370 WA 2/Quincy WA 5/Quincy 1st pick 2nd pick 3rd pick 4th pick 1st pick 2nd pick Sept. 29 Oct. 7 Oct. 13 Oct. 20 Sept. 15 Sept. 21 20.3 3.3 263.0 3.3 2.4 12.7 0.558 SOURCE: Washington Tree Fruit Research Commission Maturity evaluation As harvest approaches, field monitoring of harvest maturity commences. Starting at about three weeks prior to anticipated harvest, four to six fruit are tested weekly for firmness, Brix, and starch conversion for each genotype. When harvest parameters for a selection reach optimum levels, as determined in Phase 2, the trees are segregated into four harvest dates and only 25 percent of the trees are picked at one time. All the fruit is stripped off some sample trees and placed in a packed box. The fruit is then sorted by color, photographed, and examined for defects such as cracking. A maturity evalu- ation is performed on each set of samples at the time of harvest (See “Harvest quality parameters for Gala, WA 2, and WA 5). Fruit is then transported to a research controlled- atmosphere storage facility at Stemilt Growers in Wenatchee and drenched to reduce decay. It is then placed in regular- atmosphere cold storage for two months and evaluated again. Storage trials After the best target maturity is determined within the first few growing seasons, subsequent harvests are split into two picks unless the variety needs more in order to be color picked, as is the case with WA 2. Fruit is drenched to reduce decay, and half of each batch is treated with MCP (1-methylcyclopropene) within one week of harvest. The fruit is divided again, into two- and four-month research controlled-atmosphere storage (at 34°F) and four- and eight-month controlled-atmosphere storage (with 1% carbon dioxide and 2% oxygen) to determine storage performance under a variety of basic commercial storage scenarios. Following each storage time, fruit is pulled and held at room temperature for one week prior to evaluation. Basic fruit quality and maturity parameters, including the amount of greasiness and presence of storage disorders, are noted. Packing-line trials With increasing amounts of fruit available from Phase 3 sites, we were able to run several packing-line tests in the 2010–2011 storage season on a commercial packing line in Yakima. We evaluated the behavior of fruit when subjected to a standard waxing and packing scenario, with and without presizing. After each run, fruit was placed back into cold storage for two to three weeks, and final evaluations were performed after a one www.goodfruit.com GOOD FRUIT GROWER AUGUST 2011 23 week at room temperature to mimic shipping and store display. Performance criteria include the appearance of the wax, number of punctures, and incidence of lenticel breakdown. • 19.6 3.4 289.0 3.3 2.8 11.7 0.546 19.4 3.5 317.0 3.4 2.6 13.0 0.537 19.5 3.4 287.0 3.4 3.9 12.3 0.538 20.6 3.6 348.0 3.4 3.6 11.9 0.810 20.6 3.4 295.0 3.6 4.1 12.5 0.835 Fruit is evaluated after regular and controlled- atmosphere storage. washington tree fruit research commission