2026 Pennsylvania Tree Fruit Maturity Report - September 8

Introduction

Welcome to Penn State Extension's weekly apple maturity reports. Maturity metrics for key varieties will be tracked across the state throughout the 2026 season.

Due to the Labor Day holiday, this report is arriving a day later than normal. Fruit was collected and analyzed on Tuesday, September 9. Unfortunately the automated system sent out the alert as normal, when the report was not available. Extension apologizes for this confusion.

In this stressful year, with crops decimated by multiple springtime freeze events and hot, dry early summer weather, informed harvest timing recommendations are critical for fruit quality, particularly for apples in mid- to long-term storage. Balancing harvest decisions against sugar accumulation, color development, starch clearing, and firmness drop is difficult to perform in a normal year. These reports serve to provide insight and help inform management decisions.

Out of respect for our collaborators' need to squeeze out as much profit as possible from their available fruit, sampling of varieties may occur a week or more later than in previous years in order to reduce Penn State Extension's impact on their harvest. Please bear this in mind as recommendations this year may require quick action.

Adams County

Discussion

Last week (August 31 through September 8), Biglerville started hot, with a high of 93.2 °F on September 1, then turned wet and stormy. A multi-day severe weather outbreak moved through the Mid-Atlantic September 2-3, with numerous severe thunderstorm warnings issued across Pennsylvania, damaging wind gusts up to 60 mph, quarter-size hail in some areas, and widespread power outages; that was the big weather story of the week. Biglerville picked up 0.38" of rain on September 2 and 0.27" on September 3 as those storms passed through, with leaf wetness running 14-16 hours those two days. After that, the week turned dry and steadily cooler, with highs sliding into the upper 70s to low 80s and overnight lows dropping into the upper 50s by September 7-8, a noticeable cool-down heading into this week.

Looking ahead, the forecast turns warm and dry again. Wednesday is expected to be the warmest day, with highs near 88 °F, before cooling to the upper 70s by Friday behind a weak system that brings the week's best, though still modest, chance of clouds and scattered showers on Thursday. The weekend and early next week return to sunny, dry conditions with highs in the low-to-mid 80s, so the outlook through September 14 favors harvest and field work with little rain interference.

Varietal Analysis

Golden Delicious (Figure 1) grew from 220.6 g to 236.3 g and diameter from 3.1" to 3.3". Firmness held nearly steady, from 18.0 to 17.9 lb, while soluble solids rose from 11.0 to 12.5 °Bx and starch jumped from 2.4 to 3.4.

Red Delicious (Figure 1) firmness eased further, from 16.3 to 16.0 lb, already below the target firmness of around 18 lb typically used to mark harvest initiation for this cultivar. Soluble solids rose from 10.3 to 11.1 °Bx and starch from 3.0 to 3.3. Background dropped slightly to 1.1. Given where firmness already sits, this block should be a near-term harvest priority.

Both Reds and Golds are ready to pick in these blocks, and they should be prioritized based on destination and storage.

Jonaprince (Figure 2) sized up substantially, from 264.7 g to 412.1 g (some sample variability as well) and from 3.4" to 3.9" in diameter. Firmness dropped notably, from 18.0 to 15.2 lb. Soluble solids held close to steady at 12.6 °Bx, and starch moved from 2.9 to 4.0. With firmness falling quickly and starch converting well, this block should be harvested, especially as rain could crack these large fruit.

Crown™ Empire (Figure 3) was measured for the first time this week at 135.5 g, with strong red color at 97% and a background of 1.1. Firmness came in high at 21.5 lb, soluble solids at 13.5 °Bx, and starch at 4.0. Depending on how the apples are being stored, they can be harvested this week or next week. This variety had far fewer seeds than normal (2.7 seeds per fruit, while the occasional fully-seeded apple had 10 seeds, two per locule), which could have an impact on the size of the fruit (Figure 4).

Looking back to this week in 2024 and 2025, the mean mass of Crown™ in this block was 156 and 158 g, respectively, while the mean diameter was 2.9" for both years. There would appear to be significant differences among the fruit collected in 2026 versus that in 2024 and 2025. But these are small sample sizes (10 pieces harvested per week), so statistically it is difficult to draw site-wide conclusions. To the eye of the person collecting the fruit these years, the general impression is that it is a small-fruit year for Crown™ Empire though the color is excellent.

Smokehouse (a Pennsylvanian seedling found in the mid- to late-1800s still grown for fresh eating and its cider potential) (Figure 3) was measured for the first time this week at 289.5 g, with red color at 41.0% and a background of 2.5. Firmness came in at 19.8 lb, soluble solids at 14.5 °Bx, and starch at 4.9. The relatively advanced background and starch suggest this block must be picked immediately. This variety is showing some watercore (Figure 5). If harvested and stored, there is a possibility for the watercore in this variety to dissipate, but that should be done quickly, as the fruit is already at a starch level of 4.9.

Berks County

Varietal Analysis

Red Delicious held fairly steady this week. Mass ticked up slightly from 216.3 g to 223.6 g, and red color deepened a bit further to 81.0% coverage. Firmness eased only slightly, from 17.7 to 17.4 lb, and soluble solids and starch barely moved, at 10.6 °Bx and a starch index of 2.1. Maturity is progressing slowly here, so continue testing through the next couple weeks (Figure 6).

Golden Delicious was measured for the first time this week at 206.1 g, with a background of 3.3 and firmness of 17.4 lb. Soluble solids came in higher at 13.4 °Bx, with a starch index of 2.7. Keep tracking as starch continues to convert (Figure 7).

Historical Data

The tables below contain the data collected in previous weeks of this year's reporting cycle. It is provided to provide information to growers who may be in regions where these varieties are still developing and to serve as a historical record of the 2026 growing season. Please review the previous weeks' reports for information on harvesting.

Adams County

Berks County

Acknowledgements

Starch index values were determined by referencing the Starch Index Scale published by Dr. Randy Beaudry and the MSU Apple Maturity Program at Michigan State University. The page referenced by the hyperlink provides access to a PDF copy of the document that can be freely download.

Starch indexing for RubyMac® and Smokehouse utilized the Cornell scale found in Predicting Harvest Date Windows for Apples by Blanpied and Silsby (1992).

Because of low crop set throughout our usual sampling regions, we are indebted to the following orchards for sacrificing fruit each week to make these reports possible:

• In Adams County, Penn State wishes to thank Hollabaugh Bros., Inc., in Biglerville, and Hector Mateos in particular for his assistance.
• In Berks County, Penn State wishes to thank Keim Orchard and Frecon Farms in Boyertown, and Ben Keim and Steve Frecon especially for their collaboration.

Their kindness and generosity deserves acknowledgement.

Penn State wishes to thank Rice Fruit Company for material support that help make these reports possible.

Conclusions

Commercial fruit growers, please note: apple maturity conditions need to be monitored at a local level within one's own orchard. Before chemical products are applied, be sure to comply with current federal, state, and local usage regulations and examine the product label. Product information can be easily obtained online from CDMS.

This series of updates is made possible by a State Horticultural Association of Pennsylvania (SHAP) Extension Grant (Pennsylvania Apple Maturity Program). The authors thank SHAP for the funding.