Tree Fruit Newsletter — September 6, 2024
Maturity Report
Peaches
Peaches we are picking now: Coralstar, Veteran and Glowingstar
Apples
McIntosh is beginning to taste ready. However, the dark green peel color indicates it’s too early to pick for storage yet.
Honeycrisp is showing signs of ripening in some blocks and has acceptable flavor. It is not ready to harvest for storage, yet. Honeycrisp will develop bitter pit in storage if picked at an early stage of maturity. The Premier strain ripens early and was ready for a first pick this week.
Gala is beginning to look and taste ready, but will improve with more time on the tree. The Delta absorbance readings indicate that is it ready to pick for long-term storage.
| Variety | August 26 | August 30 | September 5 |
|---|---|---|---|
| Zestar! | 3.4 | 4.8 | |
| Gala (Fulford) | 2.2 | ||
| McIntosh (Roger’s) | 2.4 | 3.1 | 3.6 |
| Macspur | 3.9 | ||
| Honeycrisp | 1.0 | 1.2 | 2.8 |
The following is a rough guide to what the starch index numbers mean for apple ripening:
1 – 2 indicates lack of starch breakdown and generally unripe.
3 – 4 indicates some sweetness developing and generally partially ripe.
5 – 6 indicates good flavor and ready for general harvest.
7 – 8 indicates fully ripe.
| Variety | Sept. 5 |
|---|---|
| Gala (Fulford) | 0.76 |
| Honeycrisp | 1.12 |
*A measure of chlorophyll breakdown in the peel and change in ground color from green to yellow. Numbers decrease as fruits ripen. Gala and Honeycrisp readings between 0.8 and 0.3 indicate sufficient maturity for storage. Standards for other varieties have not been determined.
Starch index and Delta absorbance readings indicate a more advanced stage of maturity this year compared with last year. The temperature models predicted a Sept. 7 start of harvest for McIntosh, but apparently the model is off by a few days this year.
Renae Moran
University of Maine Cooperative Extension: Tree Fruits
PO Box 179
Monmouth, ME 04259
(207) 933-2100
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