Apple harvesting in southwest Michigan is currently focused on late-season varieties. The weekly apple maturity report from the southwest region, as part of the Michigan State University Extension fruit team's efforts, provides insights into the current state of apple maturation following their Wednesday morning calls. This initiative aims to deliver timely information on apple maturity stages across various regions, with additional resources available on the Michigan State University Extension's Apple Maturity page.
In central Berrien County, the commercial apple harvest of IdaRed and Golden Delicious varieties is nearing completion, with the maturation of Romes and Braeburn varieties progressing rapidly. The harvest season is anticipated to conclude earlier this year. Increased instances of summer rots in fruit have been observed, attributed to heat and sunlight stress compromising the protective waxy surface of apples.
Issues with watercore, a condition affecting commonly grown cultivars like Red Delicious, Fuji, Honeycrisp, Jonagold, Granny Smith, Braeburn, and newer cultivars such as Evercrisp, have been noted. Watercore development is linked to advanced maturity, with environmental conditions like hot days and cool nights playing a significant role. Specific variety updates include:
Red Delicious apples have reached a starch test average of 4.4, indicating maturity, with firmness readings averaging 17.1 lbs. This variety matured slightly ahead of the expected peak harvest date of September 17 in central Berrien County, with about half of the orchards having completed picking.
Fuji apples, with a starch test average of 3.9, have also reached maturity, showing an average firmness of 17.7 lbs. The predicted peak harvest date of September 13 for this variety in Central Berrien County appears accurate, with picking approximately two-thirds complete in the area.
IdaRed apples, averaging 3.9 on the starch test, are considered mature, with firmness readings close to the minimum suitable for mid-term controlled atmosphere storage. This variety matured slightly ahead of its predicted peak harvest date of September 24, with picking nearly finished in Berrien County orchards.
Rome apples have surpassed the mature starch threshold with an average of 4.2 on the starch test and maintain a firmness of 20.1 lbs. They matured slightly ahead of the predicted peak harvest date of September 24 for Central Berrien County, with about two-thirds of the area's harvest complete.
Evercrisp apples, still awaiting harvest, show a starch test average of 2.2, with a firmness reading of 22.6 lbs. Some fruits are exhibiting signs of internal water core.
Braeburn apples, sampled for the first time this week, show a starch conversion index of 3.4 and a firmness of 22.7 lbs. The predicted harvest date for central Berrien County is October 9th, with picking yet to start.
The apple maturity report includes detailed data on color percentage, firmness, starch levels, and soluble solids (Brix) for each variety, providing a comprehensive overview of the current state of apple maturity in southwest Michigan.
Source: Michigan State University