Tree Fruit Newsletter — August 25, 2026
In this newsletter:
- Maturity Report
- Soil Moisture Readings
Maturity Report
Peaches
This week, we are picking this week:
- TangOs
- PF 15A, 2nd harvest
- Raritan Rose, a white flesh peach. It was over-ripe by the time I remembered to pick it.
- Starfire, a traditional yellow peach
Varieties in our collection that should be next are Blazingstar and PF17.
The biggest problem has been premature fruit drop from the prolonged dry spell.
Brown rot has been showing up only in the donut peaches which are prone to skin cracking. Stink bugs were present in the orchard today, but I have not seen damage in the fruit yet.
Apples
Paulared and Zestar! were harvested this week. Starch index for Zestar! indicates that sugars have developed and that they are ready for picking and eating. Zestar! does not keep well in prolonged cold storage (>1 month).
| Variety | Starch Index 8/19/25 | Delta Absorbance* (IAD) 8/19/25 |
|---|---|---|
| Zestar! | 2.9 | 1.0 |
* IAD is a measure of chlorophyll breakdown in the peel which parallels ripening. Numbers decrease as fruits ripen. Standards for Zestar! have not yet been established.
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: partially ripe, but prone to disorders in long-term storage.
4: typically ready to pick for long-term storage.
5 – 6: indicates good flavor and ready for general harvest or harvest for short-term storage.
7 – 8: indicates fully ripe, too ripe for long-term storage.
Soil Moisture Readings
Soil moisture readings from 4 tensiometers at Highmoor Farm indicate very dry conditions. Soil moisture tension ranged from -68 cbars in good soil to -90 cbars in more sandy soil. I usually begin to irrigate when readings drop below -60 cbars.
Renae Moran
University of Maine Cooperative Extension: Tree Fruits
PO Box 179
Monmouth, ME 04259
(207) 933-2100
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