2018 Maturity Assessment: Weeks Nine and Ten

The hot, wet summer weather continues to affect our apple crop. While size is not a problem, red color development continues to be problematic in most varieties.
2018 Maturity Assessment: Weeks Nine and Ten - News

Updated: September 28, 2018

2018 Maturity Assessment: Weeks Nine and Ten

Daybreak Fuji only has about 43 percent pale red color. Larger Daybreak fruit lacking starch are prone to stem end cracks, reminiscent of mature Gala. In the samples we studied, about 10 percent of the spot-picked Daybreak Fuji had some cracking.

While Daybreak Fuji and CrimsonCrisp showed high levels of sugar with soluble solids measuring over 15 Brix in CrimsonCrisp, both are ready to harvest in Central Maryland. Daybreak Fuji had almost no starch in the flesh and tasted tree ripe in samples picked on September 19 and 25. Since spot-picking had begun in this block fruit maturity in both varieties remained relatively constant in mid-September. By October 1 the Daybreak block we sampled is likely to have been completely picked.

Photo 1. Comparison of size, color, and peel russet of two apple cultivars spot-picked in Central Maryland on September 19, 2018. Daybreak Fuji (left, center and right columns) and CrimsonCrisp (two columns of smaller dark red apples) are shown. Photo: Kathy Hunt, University of Maryland

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 some water core in Daybreak Fuji and CrimsonCrisp. That water-soaked tissue in the outer flesh was patchy, typically affecting about ¼ inch diameter areas in the flesh. The tables below show the maturity of two, relatively new apple cultivars picked in Central Maryland during September 2018.

Daybreak Fuji

DateDiameter (inches)Red Color (%)Ground ColorFirmness (pounds)Starch Pattern (1 – 8)Soluble Solids (°Brix)
September 7335Greenish yellow16.46.815.6
September 193.637Light yellow12.57.414
September 253.343Light yellow11.97.513.9

CrimsonCrisp

DateDiameter (inches)Red Color (%)Ground ColorFirmness (pounds)Starch Pattern (1 – 8)Soluble Solids (°Brix)
September 73.190Yellowish green21.55.415.8
September 193.172Light yellow20.86.815.8
September 253.280Whitish yellow19.86.915.9

CrimsonCrisp

The high red-color in this variety has been impressive this year. While this is a smaller apple than Fuji, it has had a deep red color, despite the hot wet weather. Some fruit are blemish-free while others have shown considerable roughness, notably on the stem end. CrimsonCrisp fruit are still quite firm, and the starch pattern index for CrimsonCrisp was about one week behind Daybreak Fuji at all three September sampling dates. About ten percent of the CrimsonCrisp apples sampled showed an interesting anomaly with six locules rather than the typical five locules found in most apples (Photo 3).

These observations were made using fruit grown on supported scions budded onto 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.

Aztec Fuji, Cripps Pink, and GoldRush

None of these were ready to spot-pick at Keedysville, which is about 500 feet elevation in Southern Washington County, Maryland. We will begin sampling and reporting on these three October varieties in next week’s report.

Photo 2. Color, size, and starch staining pattern of CrimsonCrisp apples (upper rows) and Daybreak Fuji (lower rows) picked in Central Maryland on September 18, 2018. Photo: Kathy Hunt, University of Maryland

Photo 3. Color, size, and starch staining pattern of CrimsonCrisp apples picked in Central Maryland on September 18, 2018. More than 10% of the fruit had six locules as shown. Photo: Kathy Hunt, 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