(Continued from Pago A 1)
control apple scab, cedar apple
rust, and powdery mildew. Also,
the root stock resistance to a com
mon disease such as fire blight is
being researched.
The most common disease,
according to Travis, is apple scab,
which causes branches to turn
brown and fall off. Through use of
varieties, the researchers have seen
some good control.
“It can be a major problem if
even one or two fungicide sprays
are missed,” he said. "Even just
one mistake can cause complete
loss of the whole crop.”
There are 11 different apple tree
varieties in one test plot, of which
nine are disease-resistant, accord
ing to Tom Clark, research aid.
Department of Horticulture. The
tree root stock is carefully exa
mined in combination with variet
Insect infestation, particularly of the lesser peach tree
borer, can be a problem for peach growers. The research
department has been Investigating the numbers of Infesta
tion with special pheromone traps that measure the amount
of the males of the borer In the area, according to Ed Rajotte,
associate professor of entomology;
research at Penn State. Here, Jim Travis inspects a special
slender*? Indie free-standi trelllsir lem.
One of the ways that growers can reduce the current levels of fungicides and get
control Is through the use of planting disease-resistant varieties, according to Jim
Travis, associate professor of plant pathology, In the panama hat. There are several
under research, which control apple scab, cedar apple rust, and powdery mildew.
Also, the root stock resistance to a common disease such as fire blight is being
researched. "
Fruit Tree Research At Ag Progress Looks At IPM
ies to discover which are the best at
disease resistance.
Also, root stock and variety
combinations and resistance to
insects and whether or not cer
tain combinations draw certain
amounts and types of insects—are
under test at the research farm,
according to Rajotte.
Several varieties of peach trees
are under test for their resistance to
cytospora canker, which is a fun
gus that attacks the dead wood.
The disease, if unchecked, travels
to the trunk, and can destroy the
tree.
Pruning and overall care is
important to control certain peach
tree diseases that attack the fruit,
particularly brown rot. Removal of
the “mummies,’* or decomposing
and dead fruit completely away
from the tree, is vital.
Prop' " “«sential. T r
There are 11 different apple tree varieties in one test plot, of which nine are
resistant, according to Tom Clark, research aid, Department of Horticulture,
looks at a hedgerow trellis system In use.
vis and Clark emphasized the
importance of keeping the tree
open to air and sunlight, and keep
ing the area at the foot of the tree
clean and free of rotted fruit and
dead branches.
“One of the most important
things you can do to eliminate
brown rot is take all the peaches
out of the tree —lake them out and
get rid of them,” said Travis. He
told the growers to make sure there
are no peaches remaining on the
ground or in the tree.
Pruning should be when bud
break occurs, because if the tree is
pruned before that time, the canker
fungus can take hold.
Clark said that peaches must be
thinned when the fruit size is
small, about A inch. They should
be thinned to 8-10 inches apart. By
keeping them thinned, fruit size
can be increased significantly,
according to Clark.
Also, insect infestation, particu
larly of the lesser peach tree borer,
can be a problem for peach grow
ers. The research department has
been investigating the numbers of
infestation with special phero
mone traps that measure the
amount'of the males of the borer in
the area.
“If you have more information
about when things are coming into
the orchard, you can be more effi
cient about any pesticides you may
have to use,” said Rajotte. “Do
some thinking about managing
your pests before you apply a
chemical spray.”
Overall, it is important to get the
exact information about the weath
er at the right limes by carefully
monitoring the weather at the exact
site to determine what kind of pest
controls to use. That’s why gather
ing weather and environmental
data is important, according to the
researchers.
Several on-site environmental
. . such as the
Austrlan-bullt KMSP system (which measures temperature,
relative humidity, leaf wetness, and rainfall at each site),
help predict the likelihood of possible disease or pest prob
lems with crops. How the machines compare (some costing
from $i,700-$2,000) and how accurately they measure is
part of the research being undertaken by doctorate student
Dave Truxell.
monitors, such as the Austrian- a better source of weather data
built KMSP system (which mea- that’s easy for someone to use and
sures temperature, relative humid- is also very convenient and that
ity, leaf wetness, and rainfall at will help them in their decision
each site), help predict the likeli- making,” said Truxell.
hood of possible disease or pest But for many growers, knowing
problems with crops. How the how much pesticide to use. when,
machines compare (some costing and if at all is a balancing act.
from $1,700-$2,000) and how “It’s easy to reduce pesticide
accurately they measure is part of use, but often, if you don’t do it
the research being undertaken by wisely, then you’ll end up with lots
doctorate student Dave Truxell. of problems with diseases and
“What we’re trying to do it find insects,” said Travis.
jm an.
spotted tentiform leafmlner at the test site. Leaves bear the
signature of the miner, “an Insect that makes a ‘mine* in the
leaf," said Ed Ra]otte, associate professor of entomology at
Penn State. A small moth lays eggs on the apple leaf, and a
caterpillar emerges. The caterpillar is so small, said Rajotte,
that it’s able to go “in between the upper and lower layers of
the leaf and makes a little tunnel Inside the leaf."
dlsease-
Here, he