2010 Redhaven peach harvest date prediction
June 8, 2010 - Author: William Shane, Bill Shane, Michigan State University Extension
Editor’s note: This article is from the archives of the MSU Crop Advisory Team Alerts. Check the label of any pesticide referenced to ensure your use is included.
Here is the 2010 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. Although the acreage of this variety in Michigan has declined with the availability of new varieties, it still is the most widely grown peach variety in Michigan and a handy benchmark time point.
The estimate is based on records I have collected on commercial Redhaven harvests in Berrien County since 1995. The Redhaven harvest onset model is based on weather data at the SW Michigan Research and Extension Center (SWMREC) Enviro-weather station approximately four miles southwest of Benton Harbor, Michigan. 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°F 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 2010, the estimated onset of Redhaven for Berrien County is predicted to be July 28, which is about five days ahead of the long-term average of August 3 and five days ahead of 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 four locations in addition to SWMREC. The spread of harvest dates were from July 28 in the southwest corner of Michigan to August 1 at the Northwest Michigan Horticultural Research Station, northwest of Traverse City. The effect of the relatively warm season from south to north in Michigan in 2010 can be seen in the prediction of early Redhaven harvest. For example, the Hart area is predicted to harvest Redhaven nine days earlier than 2009.
Table 1. Estimated Redhaven harvest onset in 2010 and 2009 for five locations based on Berrien County prediction model.
|Enviro-weather station location||Estimated harvest date for 2010||Estimated harvest date for 2009|
|SW Mich Research & Extension Center (Berrien County)||July 28||August 3|
|Sparta||July 30||August 8|
|Romeo||July 29||August 7|
|Hart||August 1||August 10|
|NW Michigan Horticulture Research Station||August 1||August 12|
The application of the model to other locations is only preliminary. In applying this model, it is important to bear in mind that heavy crop loads and cool weather shortly before harvest can slow down peach harvesting.