Agriculture Reference
In-Depth Information
If you are clearing forest or woodlots for an orchard, take at least several
years to prepare the site. Carefully examine the woodlot trees, and mark the
locations of infected trees or clusters of trees. Girdle infected trees, and leave
them standing for a year or two to speed the decay of infected roots. Remove
all stumps, then deep-rip the soil, first in one direction, then at right angles.
This practice helps drag roots from the soil. Remove and burn all roots larger
than about 1 inch in diameter.
Fallow your site for at least 2 years using green manure crops of bio-
fumigant varieties of rape, canola, or mustard. Alternate the green manure
crops with disking or other cultivation methods to maintain bare soil. You
can also grow cereal grains, which do not support Armillaria.
Before planting your fruit trees, isolate infected trees or clusters of trees
by digging a trench 2 to 3 feet deep around them. Line the trench with
plastic film, and backfill it to help prevent rhizomorphs from entering your
planting area. Remove infected trees and as much of their roots as possible,
as quickly as you find them. Do not replant in problem sites. Instead, grow
nonhost plants and use them as insectaries for beneficial organisms.
FROST DAMAGE
The pathogenic bacterium
Pseudomonas syringae,
which causes blos-
som blast or blight, increases frost damage by increasing ice formation
on leaves and blossoms at higher temperatures than would be true if
the bacteria were absent.
Where spring frosts are common, applying copper bactericides or
Pseudomonas fluorescens
in a product called Blight Ban A506 can re-
ducedamage.Thisbacteriumdoesnotcausediseaseandhelpsprotect
fruit crops from frost and disease by competing with
P. syringae
for
