Predicted 2021 apple harvest dates

These tables summarize the harvest dates for apple varieties predicted by the Enviroweather Apple Maturity Model for regions across Michigan.

Apples

The predicted harvest dates for all Michigan State University Enviroweather Stations are now available online. This season, warm conditions early in the spring led to advanced bud development. Phenology has been approximately one to two weeks earlier than the 30-year average for the duration of the 2021 season. This is the opposite of the past two years, in which cool late winter climate delayed the development of spring buds. Overall, the 2021 predicted harvest dates are earlier than normal. Most of the state is a few days early compared to the average and last year.

Challenging spring weather conditions seem to have become part of the new normal, and 2021 was no different. The season began with very warm conditions with heat accumulation and phenology approximately one to two weeks early all season. Several hard freezes occurred on April 2, 21 and 22, leading to very site-specific damage: some locations experienced total losses, while others were unimpacted, depending on development stage, variety and conditions. Most areas rushed into bloom due to hot weather over the weekend of May 2-3. Cool weather immediately afterward led to a prolonged bloom period, lasting over two weeks in most places. This has led to wide variation in fruitlet development and sizing, and will likely result in variation in ripening, requiring multiple harvests. Some apple set is from two-year-old and in some places from one-year-old wood that will produce a very mixed maturity at harvest along with the prolonged bloom period. Drought conditions could also play into maturity for 2021.

Predicted harvest dates for specific locations can be determined using the Apple Maturity Model on the Enviroweather website. These models for McIntosh, Jonathan and Red Delicious calculate predict harvest dates based on full bloom date and the temperatures in the 30 days after bloom. The model predicted dates for McIntosh appear to be much earlier and for Jonathan and Red Delicious appear to be a little later than expected. Given the weather extremes in the 30-day period used to make predictions, this is not unexpected. We have seen this before and it typically ends up being accurate. However, predicted harvest dates could be off a few days, especially due to the extended bloom and the cold weather at bloom time. Harvest dates may need to be adjusted as we get closer to harvest.

Crop load is highly dependent on specific location. In general, return bloom was extremely light to non-existent in some varieties (Honeycrisp and Jonagold) across the Midwest and Northeast this season. Gala crop load is moderate to heavy across the region, while many other varieties, including Fuji are very light. Blocks with light croploads will mature three or four days sooner then the predicted harvest dates while heavy crop loads will mature seven days later than the predicted dates.

Conditions during August and September will also affect harvest dates. If hot stressful weather occurs in August or September, apple maturity will be advanced, especially in early to mid-ripening cultivars.

Stop-drop materials. ReTain application should be applied 30 days before harvest. Harvista can be applied three to seven days before harvest. Use Table 3, 2021 predicted harvest dates for other varieties, to time ReTain applications and adjust for varieties and locations.

The tables below list the normal and predicted harvest dates for varieties across the state. Table 1 lists the predicted harvest dates for locations across the state of Michigan for 2021. Table 2 lists this year’s predictions compared to normal and last year. Table 3 lists the normal harvest dates for other varieties for the Grand Rapids area. This year's predicted dates for other non-modeled varieties are a rough estimate based on the McIntosh, Jonathan and Red Delicious predicted dates and historical experience in the Grand Rapids area. Other areas of the state should adjust non-predicted varieties based on their own history.


Table 1. 2021 predicted peak harvest dates.

Station

Full bloom date 2021

Predicted harvest date 2021

 Observer

McIntosh

Jons

Reds

McIntosh

Jons

Reds

SWMREC

28-Apr

2-May

3-May

1-Sep

27-Sep

4-Oct

Shane

Deerfield*

27-Apr

28-Apr

28-Apr

31-Aug

20-Sep

26-Sep

NA

Romeo*

2-May

3-May

3-May

4-Sep

27-Sep

3-Oct

NA

Sparta

2-May

4-May

4-May

4-Sep

1-Oct

7-Oct

Wallis

Hart

12-May

13-May

14-May

13-Sep

27-Sep

3-Oct

Wallis

NWMHRS

16-May

18-May

19-May

14-Sep

1-Oct

8-Oct

Rothwell

Table 2. 2021 predicted peak harvest dates compared to normal and last year.

Station

Days -/+ normal

Days -/+ last year

McIntosh

Jons

Reds

McIntosh

Jons

Reds

SWMREC

-12

6

2

-9

3

4

Deerfield*

-10

-1

-12

-9

-3

-9

Romeo*

-9

2

0

-14

-2

-2

Sparta

-12

5

0

-15

1

1

Hart

-3

-6

-7

-11

-8

-9

NWMHRS

-8

-5

-9

-13

-10

-11

Table 3. Normal and 2021 peak harvest dates for varieties for the Grand Rapids area.

 Variety

Normal date*

2021 predicted date

Paulared

24-Aug

20-Aug

Gingergold

26-Aug

22-Aug

Gala

10-Sep

 4-Sep

McIntosh

15-Sep

 4-Sep

Honeycrisp

18-Sep

 15-Sep

Empire

24-Sep

 22-Sep

Jonathan

26-Sep

 1-Oct

Jonagold

26-Sep

 1-Oct

Golden Delicious

2-Oct

1-Oct

Red Delicious

5-Oct

7-Oct 

Idared

10-Oct

7-Oct 

Rome

15-Oct

 14-Oct

Fuji

25-Oct

20-Oct 

Braeburn

25-Oct

 20-Oct

Goldrush

1-Nov

 30-Oct

 *Dates in this table were determined from average observations by industry members in the region.

 

2021 predicted harvest dates
2021 temperature and precipitation summary for the Grand Rapids area

 

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