Michigan statewide apple maturity report – September 25, 2024

Keep abreast of the latest apple maturity testing done in different cultivars around the state to optimize harvest times for storage and fresh picking.

Five different apple varieties.
Apple varieties in west central Michigan on Sept. 23. Photo by Emily Lavely, MSU Extension.

This report provides data to compare apple maturity across the state. This will include information from multiple regions, but if available you should consult a maturity report from your specific region. Regional reports will include more information, including updates on harvest extenders and pest and disease management.

Predicted harvest dates

2024 predicted peak harvest dates 
  Full bloom date 2024 Predicted harvest date 2024  
Station McIntosh Jons Reds McIntosh Jons Reds Observer
SWMREC 24-Apr 25-Apr 27-Apr 26-Aug 10-Sep 17-Sep Shane
Deerfield 21-Apr 23-Apr 26-Apr 24-Aug 10-Sep 16-Sep Plotkowski
Romeo 30-Apr 1-May 1-May 31-Aug 18-Sep 24-Sep Plotkowski
Sparta 30-Apr 1-May 1-May 1-Sep 16-Sep 23-Sep Brown
Hart 5-May 7-May 7-May 6-Sep 23-Sep 29-Sep Lavely
NWMHRS 11-May 12-May 13-May 11-Sep 26-Sep 2-Oct Rothwell

Table below auto calculates predicted harvest date comparisons.

2024 predicted peak harvest dates compared to normal and last year.
  Days -/+ normal  Days -/+ last year 
Station McIntosh Jons Reds McIntosh Jons Reds
SWMREC -15 -12 -11 -9 -8 -10
Deerfield -17 -11 -22 -13 -16 -16
Romeo -13 -7 -9 -11 -14 -16
Sparta -15 -10 -14 -6 -11 -10
Hart -10 -10 -11 -7 -14 -13
NWMHRS -11 -10 -15 -3 -8 -7

List of regional reports:

Northwest Michigan’s report was reduced and contained in the FruitNet email this week.

Southeast Michigan does not currently have an independent apple maturity report.

Check out Michigan State University Enviroweather’s growing degree days (GDD) Michigan map. Find your closest weather station, create an account on the website and track GDDs daily.

Maturity tables and summaries

Apple maturity sampling parameters:

  • Color % = the visual percentage of red color from 0 to 100; range is of all fruits tested.
  • Firmness in pounds pressure = measured with a Güss Fruit Texture Analyzer; range is of all fruits tested.
  • Starch: 1 = all starch, 8 = No starch; range is of all fruits tested. Using Cornell Starch Iodine Index Chart.
  • Updated MSU starch chart.
  • Brix = % sugar measured with Atago PAL-1 Pocket Refractometer
Suggested firmness and starch index for long-term and shorter-term controlled atmosphere (CA) storage by variety.
Variety Firmness (lbs)* Starch Index*
Short CA Mid-CA Long CA Mature Over-mature
McIntosh 14 15 16 5 7
Gala 16 17 18 3 6
Honeycrisp 15 16 17 3.5 7
Empire 14 15 16 3.5 6
Early Fuji 16 17 18 3 7
Jonagold 15 16 17 3.5 5.5
Jonathan 14 15 16 3.5 5.5
Golden Delicious 15 16 17 3 6.5
Red Delicious 16 17 18 2.5 6
Idared 14 15 16 3.5 6
Fuji 16 17 18 3 7
Rome 15 16 18 3 5.5
Braeburn 16 17 18 2.5 7

Southwest Michigan

Commercial apple harvesting of IdaRed and Golden Delicious is nearly done in central Berrien County. Maturation of Romes and Braeburn is moving rapidly. The harvest season will be wrapping up early this year. Summer rots of fruit have been more prevalent this year due to heat and sunlight stress on fruit, weakening the protective waxy surface of the apple.

Commonly grown cultivars such as Red Delicious, Fuji, Honeycrisp, Jonagold, Granny Smith and Braeburn can have problems with watercore. Even some of our newer cultivars like Evercrisp (a Honeycrisp by Fuji cross) have susceptibility to watercore. Advanced maturity (ripe fruit) is a required feature for the development of watercore, so factors such as hot days plus cool nights that advance fruit maturity can promote watercore development.

Region Cultivar Collection Date Red Color (%) Firmness (lbs) Starch (1-8) Soluble Solids (°Brix)
Southwest IdaRed 23-Sep 75 14.7 3.9 12.3
Southwest Rome 23-Sep 80.1 20.1 4.2 11.2
Southwest Braeburn 23-Sep 60.8 22.7 3.4 12.4
Southwest Red Delicious 23-Sep 98 17.1 4.4 13
Southwest Fuji (main season) 23-Sep 75 17.7 3.9 12.8
Southwest Evercrisp 23-Sep 59 22.6 2.2 13.5

Southeast Michigan

Growers in warmer parts of the region (Lenawee and Monroe counties) are harvesting Ambrosia and expect to go right into Red Delicious. In the Romeo area, we have moved past Cortland and Empire and started to spot pick Golden Delicious and Red Delicious. See our predicted harvest dates for southeast Michigan.

Northwest Michigan    

Sampling in northwest Michigan was reduced this week due to travel. Growers need to be moving through harvest as quickly as they are able, and again, should be making the most of the plant growth regulator products that they have available to help manage this fast-moving harvest window.

Apple maturity in northwest Michigan for apples collected on 9/24/24
Variety Color % Firmness lbs. Starch Brix %
Evercrisp 60 22.5 1.8 12.3
Fuji 57 20.9 4.8 11.5

West central Michigan

In the west central region, Rome have been harvested at some locations. Harvest of Golden Delicious, Red Delicious and Idared began this week. These varieties as well at Mutsu, Ambrosia and Aztec Fuji were tested for maturity this week.

Region Variety Collection Date Fruit Weight (g) Red Color (%) Background color (5-1) Firmness (lbs) Starch (1-8) Soluble Solids (°Brix)
West Central IdaRed 23-Sep 191 86 3.5 17.4 2.6 12.6
West Central Ambrosia 23-Sep 217 66 2.5 17 3.5 12.5
West Central Aztec Fuji 23-Sep 205 83 4.1 17.5 2.5 13.1
West Central Mutsu 23-Sep 368 30 4.2 19.4 2 13.2
West Central Golden Delicious 23-Sep 192 25 3.5 16.9 3.6 14.4
West Central Red Delicious 23-Sep 167 98 2.2 16.8 2.1 10.6

Grand Rapids region

Ambrosia, Jonagold, Red Delicious and Golden Delicious apples are currently mature. Aztec Fujis and Mutsu/Crispin apples are nearing maturity in the next week. Evercrisp was tested for the first time this week and is also almost mature.

Region Variety Collection Date Weight (g) Diameter (mm) Red Color (%) Background (5-1 rating) Ethylene (%) Firmness (lb) Starch (1-8 rating) Soluble solids (°Brix)
Grand Rapids Ambrosia 9/23/2024 216 76 73 1.15 95 18 4.1 14.3
Grand Rapids Fuji 9/23/2024 203 75 77 2.1 80 20 2.6 13
Grand Rapids Golden Delicious 9/23/2024 218 77 7 1.6 90 16.5 6.2 13.8
Grand Rapids Jonagold 9/23/2024 291 87 84 1.1 70 16.5 6.7 14.4
Grand Rapids Red Delicious 9/23/2024 177 71 93 1 70 18.2 3.2 12.29
Grand Rapids Evercrisp 9/23/2024 213 77 51 2.7 85% 25 2 14.1

Seasonal temperatures, fruit development and storability

Overripe and decaying apples in a storage facility.
Overripe and decayed Gala fruit harvested after a heat wave in 2017 and stored (duration and storage conditions not known).

Field temperatures affect fruit condition and storability. Look back at seasonal temperatures across Michigan and what it means for Gala fruit development. For more information, see the Michigan State University Extension article, Seasonal temperatures, fruit development and storability: How does 2024 compare to the previous 17 years? by Randolph Beaudry, Erin Lauwers and Bill Shane.

Upcoming events

The Great Lakes Expo

The Great Lakes Expo, held annually in early December at the DeVos Place Convention Center in Grand Rapids, Michigan, is the largest show of its kind in the country. It attracts a diverse audience of apple growers from the Great Lakes region. This year's Apple Sections take place on Tuesday, Dec. 10 and Wednesday, Dec. 11.

Sweet and Hard Cider: Tuesday Morning

Kevin Halfmann

MDARD Cider Mill Inspection Report

Paula Englin

MCA Block Grant Report

Shanthanu Krishna Kumar

Managing Polyphenols with Crop Load; Polyphenol nutrition and cider sales

Chris Swaggerty

Hill Bros. How I Did It

Apple 1: Tuesday Afternoon

Todd Einhorn

Rapid, early-season growth of Honeycrisp apples predisposes fruit to bitter pit development

Kari Peter

Optimizing management to limit postharvest apple rots while in storage

Randy Beaudry

Environmental Factors Affecting Apple Quality and Storability

Jim Schaefer, Eric Roossinck, and Jamie Kober

Post Harvest Industry Panel

Apple 2: Wednesday afternoon

Julianna Wilson

What's Bugging Apples? All the Tiny Things!

Rebecca Schmidt-Jeffris

From the bottom to the top: Orchard floor management to conserve natural enemies in orchards

Meghan Milbrath

Protecting pollinators while controlling pests in apples

Grzegorz Krawczyk

Developing challenges with management of codling moth

Cider Contest: Wednesday afternoon

The cider contest will judge the best ciders produced by Michigan cider makers (only Michigan cider producers are eligible). Here are some important details for the contest.

To enter, cider producers must submit two 1-gallon cider jugs at the Exhibitor Registration desk in the Grand Gallery concourse in DeVos Place on Tuesday, Dec. 10, from 9 a.m. to 5 p.m., or on Wednesday, Dec. 11, from 9 a.m. to noon. No entries will be accepted after noon on Wednesday.

Cider samples must be thawed by 1 p.m. on Wednesday (this is the responsibility of each cider producer, not the contest coordinator).

Cider contest judging will be on Wednesday afternoon. Judging will be held in one of the main-level Grand Gallery meeting rooms and will be open for viewing starting at 1:30 p.m.

The top five winners will be notified prior to the EXPO Social so they can be in attendance. Winners will be announced at the EXPO Social on Wednesday evening. First place receives a plaque and a traveling trophy. Second and third places receive a plaque.

Don't miss this valuable opportunity to connect with industry experts, gain valuable knowledge and explore the latest advancements in the apple industry.

We look forward to seeing you there!

To get a better sense of the Great Lakes Fruit, Vegetable, and Farm Market Expo, check out this video.

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