Fruit Health

We must ensure that any fruit we donate to charitable groups is of good quality. Use the guidelines below to see if your fruit can be donated. If a fruit owner finds that their fruit has one of these problems, he/she should indicate this on the Rescue Request form.

If fruit is not good for donating, fruit pick volunteers can judge whether they want to use it for their own purposes. It is not harmful to eat maggoty apples, unless they are very rotten. However they do not store well as the maggot growth seems to accelerate once fruit is off the tree.

To dispose of low quality fruit, place it in garbage bags to a weight of less than 50 lb, and put out for regular landfill waste collection. Do not compost infected fruit!

It is possible to see the following in Edmonton apples:

Apple Maggot – Very Uncommon

Different varieties of apples are more or less susceptible to apple maggot. Locally, it seems that earlier apples and crabapples, ripe in August, are most susceptible due to the timing of when the flies are flying (~July 1-~September 1).

But apples that ripen as late as October still have maggots. They are in lower numbers, and appear to do less damage to the fruit, but can still contribute to the spread and proliferation of apple maggot.

Signs of Apple Maggot:

    1. Dimples: These are sites where eggs have been laid by apple maggot fly. They may be more subtle and less dimpled than these.

 

    1. Tunnels inside the apples: Different varieties of apples show signs of apple maggot differently. Maybe more or less rotted from tunnels.Screen Shot 2014-07-14 at 1.23.31 PM

 

  1. Tunnels on surface of the apples: Some apple varieties will show this, some will not.Screen Shot 2014-07-14 at 1.23.20 PM

NOTE: Apple maggot has also been known to infest cherries, apricots, pears, and hawthorne. Please watch for them in these fruits as well and alert OFRE if found.

Images from:  https://www.agf.gov.bc.ca/cropprot/tfipm/applemaggot.htm

How to get Rid of Apple Maggot:

There are several strategies for getting rid of these guys:

    1. Remove all fruit for at least two summers- To stop the flies from re-infesting the apples, the apples must be removed BEFORE they fall from the tree. Maggots developing in the fruit will drop out when they are mature, regardless of whether the apple has fallen or not. If this is not possible, remove fallen apples from lawn as soon as possible.

 

    1. Stop the larvae from getting under ground- The larvae drop out of the apples and pupate in the soil under the tree. If you cover the ground under the tree canopy with a tarp from mid-August until the end of November, you can prevent the maggots from getting under ground.

 

    1. Stop the flies from emerging- Around July 1, the pupae under ground emerge as flies. One could stop the flies from succeeding by covering the ground with a tarp from mid-June to mid-August. This way, when the flies emerge, they will be impeded from flying by the tarp.

 

  1. Catch the flies- Yellow Sticky traps and red, round traps can be purchased at garden centres. These can reduce the number of flies at your tree. Yellow traps are for June-July, when the adult flies are emerging and feeding. The red, apple-shaped traps are for mid July-August, when the flies are looking for apples to lay their eggs on. Unfortunately, the yellow sticky traps also catch a lot of tiny wasps that parasitize and kill apple maggots.

Protect some apples for yourself

Because the flies have up to a 1km flying radius, flies from other trees can come infest your apples. If you want to ensure that at least some of your apples are protected, You can try one or more of the following:

    1. Cover each apple when quite small with a nylon or plastic sack. This is labor intensive, but has been done by orchards and individuals.

 

    1. Make sleeves with garden netting to place over an entire branch. This can be done by glue-gunning rectangles into a tube shape. Place the tube over a branch, tie it off, and all the apples on that branch will be protected from having the flies lay their eggs.

 

    1. Fine mesh tree covers that can be purchased online. It is basically a net that covers the whole tree!

 

  1. There is a clay product that is meant to protect apples from the flies depositing eggs, but this requires repeated coatings at the appropriate time of summer.

Note: It is possible, but unlikely for other fruit (cherries, pears, apricots) to have apple maggot, so be aware of that.

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Water Core – Uncommon

This is a condition where the apples are translucent and watery inside. They are safe to eat, but not able to be stored. Can be caused by excessive heat, high nitrogen/low calcium, and other reasons.

See the links below for useful information about this:

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Codling Moth – Uncommon, Important to Report

Larva has one tunnel to the apple core. You can see “frass”, caterpillar waste, at entrance hole.

Please contact OFRE if you find this pest.

More info: Province of British Columbia – List of Information Regarding Insects and Plant Diseases in Tree Fruits

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