Skip to Content.
Sympa Menu

nafex - [NAFEX] Spiral cane borers

nafex@lists.ibiblio.org

Subject: North American Fruit Explorers mailing list at ibiblio

List archive

Chronological Thread  
  • From: "Jim Fruth" <jfruth@tds.net>
  • To: "NAFEX" <nafex@lists.ibiblio.org>
  • Subject: [NAFEX] Spiral cane borers
  • Date: Wed, 15 Oct 2008 08:29:52 -0500

I used to wonder why I never got ahead of the raspberry/blackberry cane borers. Every Fall, when I cut out the dead canes, I religiously scrutinized primocanes for swellings on stems, cutting out and destroying infected canes. I do it again in late Spring/early Summer when cane borers are actively infecting new, growing, canes. Every year there seems to be as many (or more) than the year before but I think I just figured out why.
I had always centered my attention on the obvious swellings that circumvent canes. These swellings are almost all located at the bottom 1/3 of the canes. This year, looking higher, I'm seeing a different pattern. Cane borers are infecting the upper portions of primocanes with a different type of girdling. Instead of the grub circumventing the cane and ending where it began, the upper cane borings are girdlings in spiral patterns. These girdlings span 1-1/2, or more, of the cane's circumference. The worst part of it is that they are somewhat difficult to see because they are not as pronounced and lower cane borer swellings tend to be. I observed some swellings only after the light struck them at a favorable angle.
If we do not cut out these infected canes, they (the canes) will die just before the fruit ripens and that is FRUSTRATING. Even if there was a spray recommended for controlling them, we couldn't use it anyway because many infections occur during pollination. Sanitation is still the recommended method of control and the best time to do it is now, while primocanes are dormant.

Jim Fruth
Brambleberry Farm
Pequot Lakes, MN 56472
For jams, jellies & syrups:
www.bberryfarm.com
(877)265-6856 [Store]
(218)831-7018 [My Cell]



  • [NAFEX] Spiral cane borers, Jim Fruth, 10/15/2008

Archive powered by MHonArc 2.6.24.

Top of Page