Apple maturity testing has begun for the Grand Rapids, Michigan, region and will continue weekly through the end of harvest. Reports will be distributed following the Michigan State University Extension fruit team apple maturity calls held each Wednesday morning.
Harvest is underway for Honeycrisp and Gala. Some growers are beginning initial harvests of McIntosh and Jonagold, while Empire remains immature.
© Michigan State University
Recent weather has been cooler, with nighttime lows in the 30s and 40s Fahrenheit and daytime highs in the 60s and 70s. Forecasts show warmer temperatures in the coming week, with highs in the 70s and 80s and lows in the 50s.
Honeycrisp samples taken in Sparta on September 8 averaged a starch index of 5.1, above the maturity threshold of 3.5. Firmness averaged 15.5 pounds, and sugar levels were at 12.0° Brix. Fruits are considered mature and ready for harvest. Growers are advised to wait for acceptable varietal flavor and color before picking. Bitter pit has been observed in some blocks, especially on younger or high-vigor trees, or in orchards with low crop loads. Larger fruits are more susceptible. Fruit at high risk should be cooled quickly to 38°F, as conditioning can worsen bitter pit. High-risk fruit should be marketed promptly, while fruit intended for long-term storage should be pre-conditioned at 50°F for five to seven days.
© Michigan State University
McIntosh samples averaged 82 per cent red color with firmness at 16.7 pounds. The starch index was 3.8, below the maturity threshold of 5. Sugar levels were at 12.2° Brix. The fruit is still immature. Gala fruit averaged 92 per cent red color with firmness of 19.7 pounds. The starch index was 3.0, and sugars were at 13.1° Brix. Jonagold fruit averaged 67 per cent red color with firmness of 19.8 pounds. The starch index was 3.6, and the sugars were 12.3° Brix. Empire fruit averaged 72 per cent red color with firmness of 19.8 pounds. The starch index was 1.4, and sugars were 10.6° Brix, indicating immaturity.
To view the full report, click here.
For more information:
Michigan State University
Tel: +1 888 678 3464
www.canr.msu.edu
