Alaska Pioneer Fruit Growers Association

At War with Voles and Fungi

June 23, 2002

by Tom Marshall

 

During the spring of the Year 2002 an army of voles invaded the orchard on my homestead west of Wasilla, Alaska.  They were probably attracted by the white clover in the lawn surrounding the trees.  The invaders girdled 6 trees killing them outright and severely retarded 6 more trees.  Unfortunately, one of the vole destroyed trees was a 5 year old Oreole Apple growing on a Ranetka root showing some nice fruit buds.  I had hoped to surprise the skeptics who doubt that an Oreole Apple really will bear fruit at in place other than on the South side of a home in Anchorage.

Originally I blamed the big snow shoe hares that are often seen loping through the orchard because I could not picture a 1″ high vole eating bark off of a fruit tree trunk to a height of 30″.  After I discovered a girdled tree, which was completely protected from rabbits by 1″ mesh chicken wire, the voles emerged as the guilty party.  Apparently the voles took advantage of a 30″ Saint Patrick’s Day snow fall to gain access above the plastic tree wrap.  Once they got a taste of the bark they ate their way downward chewing up the white stretched tree wrap as they went.

Before I found the bark destruction on the rabbit protected trees I was sure that Bugs Bunny and his relatives were the culprits.  I offer all rabbits in the Matanuska Valley my sincere apologies for the curse words that I used towards them and retract all statements about making hasenpfeffer out of any and all of them who ventured into the sights of my shotgun.  This winter all of the trees will be protected by 3′ high wire screens.

The plum crop for the summer of 2002 is another story.  The self fertile Opal grafts which produced 50 lbs of ripe tasty plums last summer will probably produce less than 1 pound this summer.  Part of the problem seems to be a foot long fungus which grew undetected on one of the main grafted branches last summer resulting from a longitudinal split due to the stress of supporting the heavy fruit load.  This cannot be the only explanation because fruit production from all Opal grafts is way, way down.  The Opal branches looked really dead earlier this summer but they now have a few small new growth branches.

Fortunately the grafts of other plums on the same large Manchurian plum root stock tree itself is bearing heavily for the first time in its 12 year life.  Hopefully it will be pollinated by it’s now blooming Green Gage and South Dakota plum grafts or a nearby American seedling plum.  A potted Opal plum on a Myroban root is acting strangely this summer.  At this writing, July 24, it has 25 leaves and 25 green plums the size of large stuffed olives.  One branch has 8 plums but has never grown a leaf!  If it was possible to turn time backward I would have picked all but a few of the small plums.

I believe plums are more difficult to graft than apples.  The irregular diameter and tapers of the older wood makes for a difficult cambium layer match, but can produce successful grafts.  Once the tree starts bearing, it seems to work at growing fruit rather than making new growth.  The small diameter of first year wood is difficult to handle for grafting.  Pruning should be done in the winter to lesson the chance of introducing disease.

Nevertheless, plums are a very tasty treat about September 1st.  With the right pollination, early season pollinating insects and a large helping of luck the rewards can be fun and interesting.  Hope springs eternal in the heart of the Alaskan fruit grower.