2012 Michigan peach harvest date prediction

The harvest of Michigan peaches in 2012 is expected to be approximately 11 days ahead of the long-term average.

Here is the 2012 prediction of Redhaven harvest onset for Michigan peach growing regions. The goal is to help growers, shippers, marketers and buyers plan their season. For Michigan, the start of significant peach volume is with the Redhaven season, providing a handy benchmark time point.

The estimate is based on records collected on commercial Redhaven harvests in Berrien County since 1995. The Redhaven harvest onset model is based on weather data at the Southwest Michigan Research and Extension Center (SWMREC) Enviro-weather station approximately four miles southwest of Benton Harbor, Mich.

Regression analysis was used to determine a relationship between degree days and onset of harvest. The resulting predictive equation is D = -0.0386x + 234.9, r2 = 0.752, where x is the cumulative degree days (DD) base 50 degrees Fahrenheit from January 1 through June 3 and D = the estimated harvest day of year (e.g., January 1 = 1 and December 31 = 365 in a non-leap year). The estimation is for the onset of the main season Redhaven harvest, not including fruit with split pits that ripen several days earlier than peaches without split pits.

For 2012, the estimated onset of Redhaven for Berrien County is predicted to be July 23, about 11 days earlier than the long-term average of August 3 and 12 days behind last year. Over the years, the estimated harvest dates are generally within a few days of the actual observed harvest.

The model was used to estimate Redhaven harvest (non-split pit fruit) for three locations in addition to Berrien County. The spread of harvest dates are predicted to be from July 23 in the southwest corner of Michigan to August 4 at the Northwest Michigan Horticultural Research Station (NWMHRS), northwest of Traverse City, Mich.

Remember that other factors such as soil type, proximity to Lake Michigan, crop loads and weather shortly before harvest can affect peach ripening. The very low crop loads in many Michigan orchards due to spring frosts in the 2012 season results in large fruit that tend to ripen earlier, pushing potential harvest dates even earlier.

Table 1. Estimated Redhaven harvest onset in 2012 and 2011 for five locations based on the MSU peach maturity prediction model.

Enviro-weather station location

Estimated harvest date for 2012

Estimated harvest date for 2011

Bainbridge/ Watervliet (Berrien County)*

July 23

August 4

Sparta

July 27

August 7

Romeo

July 27

August 8

Hart

July 29

August 9

NWMHRS

July 31

August 11

* Data for the nearby Bainbridge/Watervliet station was used in 2011 and 2012 due to gaps in data at the SWMREC site.

The estimated Redhaven harvest day can also be used to approximate the harvest dates for other varieties by adding or subtracting harvest dates relative to this reference variety (Table 2). For example, a rough guess is that Loring, generally ripening 12 days after Redhaven, will harvest approximately August 16 in Berrien County in 2011.

Table 2. Typical yellow melting flesh peach variety harvest windows for the Michigan climate.

Older peach varieties

Newer varieties with significant production

Newest peach varieties

Harbinger = -33*

PF-1 = -30

Queencrest = -30

Harrow Diamond = -25

PF-5B = -25

Desiree = -26   ^^
PF-5D Big = -22 ^^
Earlystar = -18 ^
PF Early 8 Ball = -17 ^^ 

Garnet Beauty   = -10 
Early Red Haven = -10

Glenglo = -13
PF-7 = -10
Summer Serenade = -10
Rising Star = -8
GaLa = -8

Brightstar = -12   ^
PF-7A Freestone = -10 ^^
PF 8 Ball = -10 ^^
PF 11 Peach = - 4 ^^
PF 9A-007 = -2 ^^

Redhaven = 0
Reliance = 0
Vivid = +2
Bellaire = +3
PF-12A = +3
John Boy = +3

Blazing Star   = +2
Starfire = +3
Redstar = +3
PF 14 New Jersey = +4

PF Lucky 12 =   +4 ^^
PF Lucky 13 = +6 ^

Glohaven = +8
Canadian Harmony = +10
Loring = +12
Suncrest = +12

PF 15A = +6
Blaze Prince = +8
Bounty = +10
PF 17 = +12
Coralstar = +12
Allstar = +18
Contender = +18

John Boy II =   +8 ^
Gloria = +13 ^^ LA
PF 19-007 = +16 ^^
Messina = +17 ^^
Beaumont = +18 ^

Cresthaven = +24
Redskin =+26

PF 23 = +20
PF 24-007 = +22
Glowingstar = +24
PF 25 +26

PF 22-007 = +20   ^^
SweetStar = +20 ^
July Prince = +24 ^^
PF Lucky 24B = +24 ^
PF 24C Cold Hardy = +24 ^^

PF Paramount   = +24 ^^

Madison = +28
Harcrest = +28
Fayette = +28
Encore = +31

PF 27A = +30
Laurol = +41

PF 28-007 = +32   ^^
Autumn Star = +37 ^^
Flame Prince = +38 ^^
PF 35-007 Fat Lady = +40 ^^
Victoria = +47 ^^
PF Big George = +50 ^^

* = estimated harvest days before (-) or after Redhaven. A cooler year
will delay harvest dates, a warmer season will compress the harvest dates
closer together.
^ = little experience with this variety to date, ^^ = very little experience to date. LA = low acid type

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