Tree Fruit Newsletter — August 10, 2024
In this newsletter:
- Maturity Report
- Predicted McIntosh Harvest and ReTain Dates
- Preharvest intervals and sprays
Maturity Report
Cool temperatures have slowed the ripening of stone fruit on and off the tree. When picked at the partial-ripe stage, they are taking four days to reach eating quality. Partial-ripe is when they are still firm, but not ‘rock hard’, and they will be able to handle harvest and transport without bruising. They will also become easier to remove at this stage.
Peaches we are picking now: July Rose and Summer Serenade
Peaches expected to ripen next week: PF Lucky 13 and PF 8-Ball
We don’t have Reliance or Redhaven at the Highmoor Farm.
Paulared apples have begun to show starch breakdown, but are not at peak, yet. The starch index was 2.1 on Friday.
Predicted McIntosh Harvest Date
Temperature models indicate an early start to McIntosh harvest for long-term storage. In the Monmouth area, Sept. 7 is the estimated start and Sept. 16 the estimated end of harvest for long-term storage. Adjust dates according to your location within Maine. Sept. 7 is the prediction for when fruit will be at a partial stage of ripeness needed for storage durations longer than two or more months. The start of harvest is when Macs are still sour, but firm. The end of harvest for long-term storage corresponds with the development of sweetness and flavor.
Predicted Dates for ReTain
ReTain® (AVG) can slow ripening and delay fruit drop for a week or more when conditions are good. Good conditions include ample soil moisture, normal temperatures and healthy foliage that is free of disease and spider mites.
For orchard blocks where you want to delay the start of harvest, ReTain should be applied about four weeks ahead of anticipated ‘first pick’. This would be Aug. 11 for McIntosh at Highmoor Farm. A second application will be needed 7 to 14 days later if you need to prevent preharvest drop in the same block. Keep in mind that the preharvest interval is 7 days. It may also delay red color development. Two applications are allowed.
For blocks where you want to begin picking early, but also wish to continue picking the same block at a later time, apply ReTain two to three weeks ahead of anticipated first harvest. This would correspond with Aug. 18 to 25 for Macs at Highmoor Farm.
For additional ‘stop drop’ control, NAA can be applied after or with ReTain. This may be of benefit for McIntosh ‘pick-your-own’ in October. Keep in mind that fruit left on the tree to fully ripen will have limited storage potential.
For more info on ReTain, NAA and Harvista, visit the Fruit Management Guide website: Harvest management and preharvest fruit drop.
ReTain is also labeled for use on pears.
Preharvest Intervals for Commonly Used Materials on Apples
Captan – 0 days
Pristine – 0 days
Indar- 14 days
Flint – 14 days
Inspire Super – 14 days
Assail 30 SG– 7 days
Avaunt eVo – 14 days
Danitol 2.4EC – 14 days
Entrust SC – 7 days
Imidan 70W – 7 days
Rimon 0.83 EC – 14 days
For other materials, read the product label or consult the pest management guide: 9 – Summer : New England Tree Fruit Management Guide : UMass Amherst (netreefruit.org).
Please, note that the New England Tree Fruit Management Guide has been transferred to another site: Welcome to the on-line New England Tree Fruit Management Guide : New England Tree Fruit Management Guide : UMass Amherst (www.netreefruit.org/homepage).
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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