 It is often possible to see streaking of the wood, or a dark ring
around the center portion of the branch or trunk with verticillium
wilt, but a lab analysis is needed for definite confirmation.
There are no cures for any of these diseases at this time. It is
recommended to remove and destroy trees severely infected with
verticillium, to help prevent transfer from root grafting.
The list of trees affected by verticillium is very large, but
good-quality maples are very susceptible. There have been many
affected trees this year, including maples and ashes.
The only treatment is to water and fertilize to try to get new
growth and new water- and food-carrying tissues.
We have really had 20-plus years of stressful weather. Just like
us, trees like moderate weather. When we have extreme heat and cold,
and no moisture or a flood, the trees are stressed. This makes them
more susceptible to factors that are always in the environment. Try
to even out some of the extremes by watering when it is dry,
fertilizing when you do the lawn (or just fertilize the tree) and
mulching to even out the soil temperature in the root area. Remember
that many diseases can be passed with pruning equipment, so
disinfect your equipment between cuts.
Pumpkins
Many pumpkins are being planted about this time. While this
practice is great for producing pumpkins for pumpkin pie, it really
doesn't work very well for producing the Halloween jack-o'-lantern
pumpkins. The Halloween pumpkins are best planted around Father's
Day. This timing helps prevent the pumpkins from rotting before we
get to the end of October.
Many different pumpkin varieties are available, and they come in
many sizes and shapes.
The small pumpkins, ranging from 2 to 5 pounds, are called pie
types. They are normally used for cooking and fall decorations, and
include the Baby Bear variety.
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Intermediate and large varieties are primarily used for
jack-o'-lanterns. Many of the newer varieties have stronger side
walls to aid in display and carving. The flesh of these varieties is
generally poor in quality and not used for cooking.
Processing pumpkins, which are canned commercially, make poor
carving pumpkins and are more like a buff-colored watermelon in
appearance.
The jumbo or mammoth varieties are mainly used for exhibition.
These jumbos can weigh in the 900-pound range. For most homeowners,
you might want to pass on these since moving a 900-pound pumpkin
isn't for everyone. The other option is to try to grow one in place.
Vining pumpkins need at least 50-100 feet per hill, with the
larger pumpkins requiring the larger area. Hills should be 5 to 6
feet apart, and rows of hills should be 10-15 feet apart. Each hill
should have about four seeds per hill, planted about an inch deep.
The miniature varieties such as the Jack-Be-Little are sometimes
grown in rows with seeds planted every 8 to 12 inches, then thinned
to about 2 feet apart in the rows.
Keep the pumpkin bed free from weeds by shallow hoeing, and make
sure it is watered during extended dry periods. Major pests are
squash bugs, cucumber beetles and vine borers. Most often, frequent
applications of an insecticide such as carbaryl will help protect
the new runners from the vine borers and also control the beetles
that transmit the wilt virus. Apply insecticides in late afternoon
or early evening to make sure no applications are made to open
blooms that attract the bees for pollination.
Fall decoration pumpkins should be cut from the vine before the
vine dries in order to have a good stem attached to the pumpkin, but
after the color is acceptable.
[By
JOHN FULTON,
University of Illinois Extension] |
