2018 Apple Maturity Assessments: Week Eight

This week we added Autumn Crisp, Daybreak Fuji, and CrimsonCrisp to our evaluations.
2018 Apple Maturity Assessments: Week Eight - News

Updated: September 14, 2018

2018 Apple Maturity Assessments: Week Eight

While all three of these varieties showed high levels of sugar—with soluble solids measuring over 15 Brix—only two were ready to harvest in Central Maryland. Autumn Crisp and Daybreak Fuji had almost no starch in the flesh and tasted tree ripe. CrimsonCrisp also had good red color and soluble solids, was mature and ready for long-term storage, ripe with a starch value of 5.4 and 21.5 pounds firmness.

Many sunburned Daybreak Fuji fruit were seen on the trees, and some were included in our spot-picked sample. As in past years, we also noted water core in Daybreak Fuji and CrimsonCrisp but not Autumn Crisp. That water-soaked tissue in the outer flesh was patchy, typically affecting about ¼ inch diameter areas in the flesh.

Daybreak Fuji fruit are remarkably responsive to hot weather. In 2017 Daybreak Fuji were picked about three weeks earlier than usual. August 2018 was also warmer than normal; therefore, growers not already picking Daybreak Fuji and Autumn Crisp should check their fruit for maturity.

Photo 1. Three apple cultivars spot-picked in Central Maryland on September 7, 2018. Daybreak Fuji (top row) Autumn Crisp (middle) and CrimsonCrisp (bottom) are shown. Photo: Kathy Hunt, University of Maryland

Table 1. Maturity of three, relatively new apple cultivars picked in Central Maryland on September 7, 2018.

CultivarDiameter (inches)Red Color (%)Ground ColorFirmness (pounds)Starch Pattern (1 – 8)Soluble Solids (°Brix)
Autumn Crisp3.365Light yellow13.37.615.1
Daybreak Fuji335Greenish yellow16.46.815.6
CrimsonCrisp3.190Yellowish green21.55.415.8

Honeycrisp

With our prolonged period of hot wet weather, picking Honeycrisp has not been easy. Not only has it been difficult to get into the orchard, but red color has been slow to develop. For the first time in almost a month, the spot-picked fruit we tested had increased in both percentage and intensity of red color. When these fruit were tested in the laboratory, they were still crisp although they had softened to 13 pounds firmness. Right after we took these samples, the grower began spot-picking the tops of these trees. To aid you in making spot-pick decisions, Penn State Extension published a calculator to determine potential economic returns when spot-picking this valuable variety.

These observations were made using Honeycrisp fruit grown on size-controlling rootstocks. Small differences in microclimate or orchard management practices may make a large difference in maturation. Management practices that might hasten fruit maturity are summer PGR applications to enhance return bloom, mechanical pruning to increase red color development and the use of stop-drop sprays.

Table(s) 2. These tables show the maturation of spot-picked Honeycrisp apples at two locations during August and September 2018.

Honeycrisp – Central Maryland 575 feet elevation

DateDiameter (inches)Red Color (%)Ground ColorFirmness (pounds)Starch Pattern (1 – 8)Soluble Solids (°Brix)
10-Aug-1833Light green20.61.411.3
21-Aug-18350Yellowish green16.36.811.5
28-Aug-183.245Yellowish green16.37.513.9
4-Sep-18Harvest completed

Honeycrisp – Adams County Pennsylvania 1,200 feet elevation

DateDiameter (inches)Red Color (%)Ground ColorFirmness (pounds)Starch Pattern (1 – 8)Soluble Solids (°Brix)
14-Aug-18318Light green18.21.210.5
21-Aug-18340Yellowish green17.32.811.4
28-Aug-183.229Yellowish green16.13.612
4-Sep-183.439Light yellow14.46.112.7
11-Sep-183.445Light yellow136.913.1

Photo 2. Honeycrisp apples shown in the photo were spot-picked on September 11, 2018. In the past week, fruit size and red color development increased, while starch and firmness decreased. Photo: Kathy Hunt, University of Maryland

Atago, Shinko, and Olympic Asian Pears

This week we also added these three varieties of Asian pear to our maturity evaluations (Photo 3). While not many Asian pears are grown in the region, their plantings are increasing, especially for direct marketers. This week we found Atago and Shinko were both beginning to tree-ripen. While the ground color of the spot-picked fruit was dark green in these two varieties, about 40 percent of the peel had the orange tint that comes with tree-ripening (Table 3). All three of these varieties had relatively soft, juicy fruit. Firmness was measured using the smaller ‘pear’ tip on the penetrometer. Using that tip, firmness was below ten pounds.

Growers have two major problems handling this crop. The main problems have been marking of clear-skinned yellow varieties and internal breakdown in the late-season varieties, Olympic and Ya Li. Yesterday Mike Newell finished picking Yoinashi and Shinko at the Wye Research and Education Center on Delmarva. He also picked 30 Olympic Asian pear fruit to check for internal browning. One-third of the Olympic pears had some flesh browning. This was primarily on tree-ripe fruit, although some of the partially-ripened fruit also had flesh browning. In the partially-ripe fruit, the browning was confined to the orange side of the fruit.

We believe internal browning is triggered by hot summer weather. To reduce internal browning problems, growers should spot-pick mature Olympic fruit before they tree-ripen and turn orange. Since Asian pears have a thin skin, they also need to be handled carefully. Clear-skinned, yellow varieties such as Shinseiki and Seigyoku are particularly prone to marking (Photo 4). To avoid marking problems, growers should spot-pick and field pack the fruit. They also need to educate their wholesale buyers and consumers to avoid these problems during marketing and handling.

Photo 3. Three varieties of Asian pear, picked in Central Maryland on September 11, 2018. Atago (top row), Shinko (middle) and Olympic (bottom). Atago and Shinko are tree-ripe while Olympic is likely to be picked in two to three weeks. Photo: Kathy Hunt, University of Maryland

Table 3. This table shows the maturation of spot-picked Asian pears in Central Maryland on September 7, 2018.

CultivarDiameter (inches)Orange Color (%)Ground ColorFirmness (pounds)Starch Pattern (1 – 8)Soluble Solids (°Brix)
Atago3.545Pale green9.813.5
Shinko3.140Dark green6.912.1
Olympic

Photo 4. Marking of clear-skinned Asian pear fruit. These fruit were likely damaged after picking, when in transit or repacked for marketing. To avoid this problem, growers are advised to field pack fruit and plant russet-skinned varieties. Photo: Chris Walsh, University of Maryland

Authors

Tree Fruit Cultural Practices and Production Systems Sustainable Specialty Crop Production Support for Next Generation Farmers from Diverse Backgrounds

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Christopher S. Walsh