Pear pest control

Asked February 19, 2018, 3:06 PM EST

I have moved to a new house with an ancient pear tree (Bartlett?)that we have been working on pruning back into shape. It gets tons of fruit in the late summer but almost all of it rots from the inside out and falls of the tree becoming inedible. I am wondering what we can do to prevent this?

Jackson County Oregon

3 Responses

Thank you for your question about your pear tree. Here is a link to an OSU article on home orchards, and management of various pests--with legs and without! Without a photo of the fruit, both outside and inside, it is more difficult to diagnose whether your tree has a fungal infection, or is home to insects which invade pears. If you look on page 5, however, you can see the various potential problems, and what you can begin doing now to prevent them later.

You might want to take a look at the photos in this article, which shows what the coddling moth looks like, and what damage they do inside the pear. Is this how your pears looked? If they did, in addition to pruning your tree, you also should rake up and remove as many leaves, stems, twigs and especially rotten fruit from last year, because this year's 'crop' of moths have overwintered in all of those places.

You didn't mention any leaf, bud or trunk damage from last year, where symptoms of the conditions and insects described in the first paragraph of the "pear" table will be apparent. Both copper and sulfur are organic applications, and can stem these problems before they impact your tree's health. Likewise, neem oil and insecticidal soaps are organic, and effective against those problems listed.

I hope this answers your question. If not, please write back. Good luck!

Thanks for your response. We did not have coddling moth, the pears just would turn brown from the inside out and fall off but did not have trails like the picture. My husband saw damage to the upper tree (that has now been removed and pruned) that looked like insects had bored into the wood. That is not apparent lower down on the remaining tree. Would you recommend a certain spray in this case in addition to the pruning?

Thanks for your update. After researching non-pathogenic caused fruit rotting, and with no reliable data on which insect might be the problem, I think the rotting is caused by your picking them too late, which is explained here. The second possibility is bacterial blight. As this article explains:

"Bacterial blight is caused by a bacteria (Pseudomonas syringae) that enters Bartlett pear trees either through a pruning wound, on an insect's body (such as boring insects) or a natural opening, such as a pollen tube. This bacteria thrives in cool, wet weather and often infects trees during rainy spring weather or through overhead irrigation. In European pear trees, bacterial blight affects the fruit of the tree only, causing cankers to appear (dead, sunken areas) on the skin of the fruit. These are not only unattractive, but render the fruit inedible unless the affected areas are cut out of the pears. It is not possible to cure this disease after it has infected the fruit of the tree, but it can be prevented by pruning only when the tree is dry, sterilizing pruning tools between cuts and sealing wounds. In addition, make sure the trees have plenty of air circulation around them so they do not stay wet for long periods of time."

As to whether you spray or not, as I indicated before, there are organic sprays to reduce the possibility of fungal and insectal problems, that opening up the tree's upper branches won't solve in and of itself. You just risk having them, which will either compromise your tree or make for another year's worthless crop. I'd spray what is listed in the pear chart in the EC 631 publication. Good luck!