Tree Fruit Newsletter — July 14, 2025
In this newsletter:
- Fruit Price Survey
- Bitter Pit Risk Management
- Preharvest Intervals
- Peach Harvest Dates
- Leaf Sampling Reminder
Price Survey
I will be sending out a price survey in the next newsletter. This will be to calculate an average for farmstand and pick-your-own prices per pound and per 10-lb. tote at the stand and for PYO. If you would like to know the average price for a particular volume or for something else, let me know before next week.
Bitter Pit Risk
Foliar calcium sprays should continue to harvest. When calcium is sprayed on trees, it needs to directly contact the apples, so increasing spray coverage is one way that you can increase calcium in the fruit. Use a foliar calcium product with at least 10% calcium if you grow Honeycrisp. Calcium also benefits McIntosh apples that will be stored for a long time. The light crop load will lead to large fruit, a risk factor for fruit softening.
Many Honeycrisp orchards in Maine have a light crop load this year which puts them at risk of bitter pit in storage this year. However, the prevailing temperatures have been cool this spring and summer which could reduce risk this year, so it’s hard to predict how much bitter pit to expect.
Peel sap analysis can tell us the calcium concentration in fruit by harvest time, a predictor of bitter pit risk. I plan to collect samples in late July and again in late August. If you want your orchards tested, contact me soon to make arrangements for sample collection. You will need about 20 apples from each block, and they need to be representative of the fruit size and sun exposure of the apples that will go in storage.
The relative risk of bitter pit can be predicted by harvesting 100 apples from each block three weeks before anticipated first pick, August 20 to 25 for the original strain of Honeycrisp. Harvest may be early this year because of the light crop load. Hold these 100 apple at room temperature for three weeks. Bitter pit will begin developing after two weeks and should be fully evident by 21 days. Compare the amount of bitter pit among the different blocks.
Soil pH should be maintained close to 7 rather than 6.5 in Honeycrisp orchards. The higher soil pH will make it easier for roots to take up calcium, but this may take a few years to have a marked effect.
Preharvest Intervals for Tree Fruits
This was taken from the New England Tree Fruit Guide, so double check the actual label.
| Fungicides | Apple | Peach | Plum |
|---|---|---|---|
| Captan | 0 | 0 | 0 |
| Pristine | 0 | 0 | 0 |
| Merivon | 0 | 0 | 0 |
| Cevya | 0 | 0 | 0 |
| Flint Extra | 14 | 1 | 1 |
| Luna Sensation | 14 | 1 | 1 |
| Indar 2f | 14 | 0 | 0 |
| Inspire Super | 14 | 2 | 2 |
| Sulfur 80 WDG | Not stated on label | Not stated on label | Not stated on label |
| Fontelis | 28 | 0 | 0 |
| Insecticides | Apple | Peach | Plum |
| Surround 95WP | 0 | 0 | 0 |
| Neemix | 0 | 0 | 0 |
| DiPel DF | 0 | 0 | |
| Pyganic | Not stated on label | Not stated on label | Not stated on label |
| Sevin (Carbaryl) | 3 | 3 | 3 |
| Exirel | 3 | 3 | 3 |
| Assail 30 SG | 7 | 7 | 7 |
| Asana XL | 21 (28 on pears) | 14 | 14 |
| Imidan | 7 (14 day for PYO) | 14 | 14 |
| Entrust (Spinosad) | 7 | 1 | 7 |
| Rimon | 14 | 8 | 8 |
| Avaunt eVO | 14 (28 days on pears) | 14 | 14 |
| Intrepid 2F | 14 | 7 | 7 |
| Danitol 2.4 EC | 14 | 3 | 3 |
| Beseige | 21 | 14 | 14 |
Peach Harvest Dates
Peach harvest dates for many varieties are included in the accompanying pdf file Peach Varieties.
ReTain is labeled for use on peaches, nectarines and plums to delay harvest. One pouch per acre applied two weeks prior to anticipated first pick. ReTain has a 7-day PHI.
Leaf Sampling Reminder
Mid to late July is the ideal time to collect leaves for nutritional analysis. Visit the University of Maine Soil Testing Lab to learn about all their services or access forms: Analytical Lab and Maine Soil Testing Service. You can submit a check with your sample or contact the lab regarding payment. 207.581.2945
Cost for the standard foliar analysis is $30, and this includes analysis for Nitrogen, Phosphorus, Potassium, Calcium, Magnesium, Aluminum, Boron, Copper, Iron, Manganese, and Zinc.
The standard soil test is $20 and includes pH; Lime Index; Available Phosphorus, Potassium, Calcium, Magnesium, Sulfur, Boron, Copper, Iron, Manganese, Sodium, Zinc, Organic matter, Calculated Cation Exchange Capacity. Soil samples submitted with a matching leaf sample may get fewer elements tested (calcium, potassium, magnesium and pH).
Winter discount – run on any soil sample received at the lab between January 1 and March 1. Sample in late fall, set aside to air-dry until discount period. Report will be sent out within 4 weeks. This discount applies to the basic Standard Soil Test only.
Samples can be sent to: Maine Soil Testing Service, University of Maine, 5722 Deering Hall, Orono, ME 04469
Renae Moran
University of Maine Cooperative Extension: Tree Fruits
PO Box 179
Monmouth, ME 04259
(207) 933-2100
Mention of a trademark, proprietary product, or vendor does not constitute a guarantee or warranty of the product, nor does it imply approval or disapproval to the exclusion of other products or vendors that may also be suitable.
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