[NAFEX] Field Grafting
michael at herbsandapples.com
Mon Apr 6 08:39:58 EDT 2009
Barbara in Virginia used the term "field grafting"... so I'll add some
observations from northern New Hampshire on that.
A few years ago I ordered some small caliper Bud.118 rootstock (3/16 inch,
as determined by Meadow Lake Nursery) with plans to do summer budding.
Clonal rootstock can come with very few roots so this also seemed to make
sense in getting the roots established... though Bud.118 does seem better
than most in this regard. Of course, life being life, I never did the
budding... which brought me to the following spring with two hundred
rootstock in the ground, planted in two separate nursery beds. I grafted on
my knees, low to the ground, in lots of about 20-30 at a time, between the
very first sign of green tip on my bearing trees through about pink. This
four week effort wasn't so much a planned trial as just what happened. The
first lot all took and had impressive shoot growth (for the north)of three
plus feet by summer's end. The next two lots also all took but the resulting
shoot growth was 6 to 12 inches shorter. The last two lots had up to a third
misses with shoot growth of 2 feet or less.
That still left me with 50 or so rootstock in the other nursery bed that I
did not get to that spring. These now 5/8 inch caliper Bud.118s were
barkgrafted the following spring, 2 scions per tree, in the half-inch green
time slot when bark was definitely slipping. All took, growth was on the
order of four feet with plenty of side branches in evidence. I trimmed back
the weaker shoot but did allow it to grow all that summer to contribute to a
complete callus, removing it entirely the following spring.
Last year I semi-repeated this effort by field grafting another 100 Bud.118
put out as liners the spring before... thinking I now knew better to get
this all done "on time" the week of green tip. Last summer we had something
like 30 inches of rain in July and early August, and given the location of
these wee trees, they basically floundered. Shoot growth varied considerably
from 8 inches to two feet at best. The weaker grafts either winterkilled or
were broken off by an icy crust this winter, giving me a net take on the
order of 75% ... all of which want another season of growth before going out
in the orchard.
This year I'm returning entirely to bench grafting, in the greenhouse, with
me in the standing position. I'm doing that now, setting aside the grafts to
callus for planting out in about a month's time.
Don't know if this adds to understanding callus dynamics... as it seems this
experience was more about maximizing the years it takes to grow a decent
Lost Nation Orchard, NH
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