Skip to Content.
Sympa Menu

nafex - RE: [nafex] Pruning and Growth

nafex@lists.ibiblio.org

Subject: North American Fruit Explorers mailing list at ibiblio

List archive

Chronological Thread  
  • From: "Raby, Brian {D204~Indianapolis}" <BRIAN.RABY@ROCHE.COM>
  • To: "'nafex@yahoogroups.com'" <nafex@yahoogroups.com>
  • Subject: RE: [nafex] Pruning and Growth
  • Date: Sat, 13 Apr 2002 22:41:42 -0400

All,

This conversation stimulated me to go through some of my college books (1979
to1982) to check up on the subject.

According to what I've read, the auxin produced in the growing tip of most
apple trees produces ethylene that translocates to the lower buds on the
branch preventing growth. Either an application of Cytokinins, or scoring
just above a bud you wish to break (which basically prevents the downward
travel of the ethylene to the bud) causes side branches to grow. It is a
very difficult topic to explain via e-mail.

A great source of pruning, growth hormones and the like are in a probably
obscure 1981 shortcourse proceeding that I purchased back in 1982. It is
called "Tree Fruit Growth Regulators and Chemical Thinning", edited by
Ronald B. Tukey and Max Williams. To compliment your response Don, Dr.
David Ferree writes on page 100 "Pruning in August after terminal bud set
has been shown by several investigators to improve fruit color, increase
fruit calcium, decrease cork spot, and promote the development of stronger
and more fruitful spurs in the older section of the branches." He also
writes that researchers in Indiana have utilized summer pruning as a means
of dwarfing peach tree to permit high density plantings. It consists of
mechanically shearing new growth on the tree periphery in half about
mid-June. The shoots grow and again are cut in half in mid-July with little
regrowth occurring. It resulted in yields of nearly 500 bushels per acre on
3 yr. old Redhaven trees in an Ohio study. This mechanical pruning in tart
cherries in Michigan also results in increased fruit size and sustained
yields.

Here's another insert I found interesting; scoring. Here's how Dr. Ferree
describes it:" Scoring (a circumscribing cut through the bark but not into
the wood) is a technique that fits somewhere between training and pruning.
Scoring the trunk 2 weeks after bloom results in a growth reduction similar
to that achieved by Alar and ethephon and has proven more consistent in
promoting flower initiation than these chemicals. Scoring acts by
interrupting phloem translocation which causes a buildup of the carbohydrate
products of photosynthesis in the branch portion above the cut. Growth
hormones produced in the apical meristems and young leaves are translocated
in the phloem (which transports products downward in a plant) and thus also
play a role in the effects produced by scoring. The photosynthetic and
transpiration rates of leaves above the cut are reduced for up to 2 weeks
but recover to control levels of unscored plants in 4 weeks." He goes on a
says "Since scoring requires less than 1 minute/tree, it is a sound practice
economically and should be considered on young trees where a slowdown of
growth and an increase in flower initiation is desired (I have a few trees
like that). He warns, however, that scoring does increase the risk of
fireblight damage and winter injury in the scored section of the trunk.

Ed, my question to you is does all of this make sense to you or is it all
"old school"? I've been away from the trade too long to know what the
common practices are to help promote flower initiation.

Thanks for letting me bend your ear (and eyes) a bit.

Brian
Sheridan, IN


-----Original Message-----
From: Don Yellman [mailto:dyellman@earthlink.net]
Sent: April 13, 2002 8:46 PM
To: nafex@yahoogroups.com
Subject: [nafex] Pruning and Growth


Tom:

Agree with Ed. It seems to me the answer is selective pruning conducted
throughout the growing season. This can also assist formation of
fruiting wood in otherwise reluctant trees. Then you won't have to
worry about auxins and cytopathic hormones, which are difficult to see
and even harder to train. The trees I have summer pruned here are
blooming much more profusely than those I have not, and are otherwise
just as healthy. I managed to shock a 12-year old Early Cortland that
had never really bloomed by some pretty severe pruning last August.
This spring it is covered with blooms.

Rgds, Don Yellman, Great Falls, VA




[Non-text portions of this message have been removed]


------------------------ Yahoo! Groups Sponsor ---------------------~-->
Kwick Pick opens locked car doors,
front doors, drawers, briefcases,
padlocks, and more. On sale now!
http://us.click.yahoo.com/ehaLqB/Fg5DAA/ySSFAA/VAOolB/TM
---------------------------------------------------------------------~->





------------------LIST GUIDELINES----------------------

1) Please sign your posting. Include climate and location information if
relevent.
2) Attached files will be stripped from your messages. Post attachments on
the www.YahooGroups.com website.
3) To unsubscribe send a BLANK message to
nafex-unsubscribe@yahoogroups.com
4) Include only pertinent comments/questions when replying to a posting and
NOT the entire message (especially if the initial posting was large).

Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/






Archive powered by MHonArc 2.6.24.

Top of Page