Wednesday, June 14, 2017

The ability to walk away from sunk costs

Subtitle: Dealing with virus in the orchard.  Discard what is bad.  Avoid all evil.

Every enterprise must deal with "The Sunk Cost Problem".  It could be the military abandoning a weapon system that became obsolete overnight.  It could be a nation walking away from an energy strategy that proved more promise than performance.  It could be an industrial firm shuttering a factory beset with irreparably poisoned labor relations or with obsolete "core processes" that are not amenable to upgrading.

At a more personal level it could be deciding to move because of urban blight or gang activity.  It could be as humble as deciding to remove a cherished specimen from your garden or orchard.

Walking away from sunk cost is very hard.  Decision makers must be stubborn and must be able to drive through "nay sayers" to be effective.  It is not surprising that those same decision makers often find it hard to abandon the very efforts they sank their hearts and souls into.  The decision maker must put aside denial in the face of irrefutable evidence and the certainty of staggering costs.

In my case it was the sudden recognition that I had a tree infected with Apple Mosaic Virus in the middle of my orchard.  (A tip of the hat to Bill Shane)

The mottled pattern on the leaves tends to manifest a specific temperatures when the leaves are extending.  Consequently, you will see a shoot without the mottle, then mottled leaves, then leaves without mottling.  This is a characteristic of many viral diseases in plants.

These "fractal looking" bleached patterns are characteristic of Apple Mosaic Virus.  Different cultivars exhibit symptoms to different degrees.  Jonathan, Granny Smith, Golden Delicious are good indicator varieties.
Once a tree has a viral disease it cannot be cured.  The usual cause of the disease is grafting "infected" scion onto an uninfected tree.  That is one of the downsides of grafting.  You can bring infections into your orchard.  In my case it was a scion of Lord's Seedling that I purchased from a now defunct nursery.

The disease can also spread to nearby trees via roots that have crossed each other and grown together.  Having one infected tree puts your entire planting at risk.

Some viral diseases (but not Apple Mosiac Virus) are easily spread by leaf hoppers or dagger nematodes and other "bugs".

The tree is on the burn pile.  This hurt.  I had five producing apple trees in the "serious" orchard.  Now I have four.  I have many young ones coming along but it will be a few years before they are producing.

Holes drilled down into the stump close to the bark

Holes and exposed surface of stump sprayed with herbicide.
The only control, once you know you have it in your orchard is to cull with extreme prejudice.

Viral diseases reduce production
Estimates for the loss of production due to Apple Mosiac Virus range from 25%-to-50%.  Think about it; you may have planted ten trees in your home orchard.  You are caring for ten trees, spraying ten trees...and you are only harvesting five trees worth of fruit.

At one time seedlings of Hewe's Virginia Crabapple were very highly regarded rootstock for apples.  The trees were vigorous, precocious and very productive.  Hewe's Virginia Crabapple fell out of favor because it is exquisitely sensitive to virus.  It falls over dead at the first whiff of most, common apple viruses.

But think about this in reverse:  If one virus reduces yield by an average of 30%, then how much will the yield be reduced by two or three, otherwise asymptomatic viruses?  What if you had a rootstock that selected for "clean" scion wood because that was the only kind that did not kill the rootstock.  Hewe's Virginia Crab was a GO-NOGO gauge for the otherwise invisible 900 pound gorilla riding on the saddle of the race horse.  That fact that the tree fell over dead as soon as it got a virus made the infection self-extinguishing.

These root suckers show symptoms of Apple Mosaic Virus proving that it is in the roots.
One of my visions was to have a small stoolbed where I could produce some of my own rootstock.  I pictured 20-to-50 rootstock a year.  Some of those rootstock were suckers that sprung up from this tree.  I now have to grub out those stools and start over.

1 comment:

  1. Sorry to hear that, but you DID do the right thing, painfully as it is...


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