Tree Fruit Newsletter — July 29, 2026
In this newsletter:
- Leaf and Soil Sampling
- Reminder to Pay Attention to Preharvest Intervals
- Peach Disease and Pest Issues
- Peach Harvest Maturity
There is Still Time for Leaf and Soil Sampling
Mid to late July is the ideal time to collect leaves for nutritional analysis. Visit the University of Maine Soil Testing Lab webpage to learn about all their services or access forms. Soil samples can be collected anytime.
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. Please, specify on your submission form if you want the standard test or comprehensive test (includes nitrogen and costs $25). Soil samples submitted with a matching leaf sample may get fewer elements tested, so specify which nutrients should be measured.
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.
Pay Attention to Preharvest Intervals for Spray Materials
Harvest for apples, peaches and plums will begin soon, so check preharvest intervals (PHI’s) for any sprays in the next few weeks. Some materials should not be applied this time because their preharvest interval (PHI) can be several weeks. The PHI is the wait time between a pesticide application and when a crop can be harvested. The label will state how long the crop must remain in the garden or field after spraying. Waiting times for the same fruit or vegetable can differ between products. Always check the product label for any recent changes to PHI’s.
Links to the spray table for apples and peaches (links will open in a new tab):
Apples Summer Spray Table from New England Tree Fruit Management Guide
Stone Fruit Summer Spray Table from New England Tree Fruit Management Guide
Peach Disease and Pest Issues, Michael Basedow
Excerpted from the Cornell Cooperative Extension Tree Fruit Newsletter:
For brown rot, we usually expect to make two to three preharvest sprays. The first should go on about 14-21 days prior to harvest. The second application should be made 7-14 days later, with a final application just prior to harvest. We strongly recommend saving your low PHI single site materials (Cevya, Mervion, Indar, Luna Sensation, Pristine) for your final spray.
Anthracnose is another peach rot caused by the same genus of fungi that causes bitter rot in apple. Captan is the recommended fungicide.
I continued to find some native stink bugs and their associated damage in a few peach plantings. We have also set out some traps for brown marmorated stink bug. We have not yet caught any BMSB. If you begin to catch nymphs or adults, and/or start to notice damage to your fruit, some management options include Assail (7 day PHI), Brigade (14 day), Danitol (3 day), and Leverage 360 (7 day). Venerate is a 0 day PHI, and is rated as good. Admire pro is also a 0 day, but is listed only for suppression.
Oriental fruit moth captures were still down in our traps last week, despite NEWA predicting peak flight. Keep an eye on your traps, and be sure to rotate materials for the next generation if an application is warranted. For example, if you used the groups 3’s and 22’s for your petal fall applications, consider shifting to group 4’s (Assail), 28’s (Altacor, Exirel, Verdepryn) or 5’s (Delegate, Entrust,) for the 2nd.
Lesser and greater peach tree borer flight continues. We began catching both in Peru in late May, and counts of lesser peach tree borer continue to be elevated in Peru. Control for borers generally consists of up to three trunk applications of pyrethroids, applied in early June, July, and August. Check the guidelines for product recommendations.
Green peach aphids may be controlled with products such as Actara, Admire Pro, or Assail. The recommended treatment threshold in peach is 2-3 colonies per tree.
Japanese beetles have arrived and can now be found in peach plantings. Materials for them include Verdepdryn (7 day), Assail (7 day), Barythroid (7 day) and some pre-mix products like Leverage (7 day).
Peach Harvest Maturity
Firmness and ground color are the best indicators of when to pick peaches. For immediate sale with minimal shipping, they can be harvested at more advanced stages of ripening but will be prone to skin tearing at harvest and bruising in transport.
Flesh firmness decreases as fruit matures. Firmness can be measured by a hand-held penetrometer with a 5/16 inch diameter plunger (smaller tip than the one for apples). Peaches destined for short-distance shipping should be harvested when firmness is 8 to 12-lb to prevent bruising. For local sale with minimal shipping, firmness should be in the 6 to 8-lb range to allow for a few days of shelf life. Fruit harvested soft will likely bruise in transport and marketing.
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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