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The first item of business is to know what type of weeds you
want to control. This will make a big difference in what product
or products you select. The main products used for broadleaf
weed control in lawns are 2,4-D, MCPP, dicamba, a combination of
those three products, and triclopyr.
Let's start with the triclopyr since it's probably the
easiest to discuss. Its place in weed control is for
hard-to-control weeds and woody plants. It also improves control
of violets. It can be added to one or more other chemicals to
provide broad-spectrum control. Some blends now contain
trichlopyr, so check the label. There are many trade names for
products containing trichlopyr, and they seem to change every
year. Just check active ingredients.
The old standby is 2,4-D. It is good on carpetweed, chicory,
dandelion, lambsquarters, plantains and wild carrot. There are
amine forms and ester forms. The ester will generally give
better control of more weeds and is generally not water-soluble
(except for a hard inch of rain soon after application), but it
does have vapor drift potential. MCPP is good on chicory,
lambsquarters and white clover. Dicamba is good on black medic,
chickweeds, chicory, dandelion, dock, henbit, knotweed,
lambsquarters, pearlwort, purslane, red sorrel, thistles, white
clover, wild carrot and yarrow. The combination of all three
products will pick up all of those listed for the individual
products, plus a few more, such as mallow, speedwell and wild
onion. The combinations are sold under many different trade
names, so check the active ingredient list for ones you need.
My annual disclaimer for application of these types of
products is: "Beware of potential drift from these products."
Not only can the spray move under windy conditions while you are
spraying, but particularly with dicamba, the products can drift
as a vapor for up to two weeks after spraying, with hot and
humid conditions.
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Cedar apple rust
Cedar apple rust is caused by a fungus that attacks
two different groups of trees. The first group is apples and crab
apples, and the second is juniper and eastern red cedar. In order to
survive, the fungus must "move" from one group of hosts to the
other.
On juniper or eastern red cedar, small galls,
three-eighths to 1 3/16 inches in diameter, develop on needles and
small twigs throughout the tree. When mature, these galls swell
considerably and repeatedly produce orange, gelatin-like horns
during rainy spring weather. As spring rains subside, the galls die,
which may cause death of the twig from the gall to the tip.
On susceptible crab apples and apples, tiny yellow
spots appear on the leaves after infection in the spring. As the
spots mature, they become yellow-orange and swollen, with a red
border, and develop tiny black dots in the center of the lesion. By
midsummer, small cup-like structures with tubes are visible on the
undersides of mature leaf lesions. The fungus may also infect fruit
and tender twigs of very susceptible crab apple and apple varieties.
The entire life cycle takes about two years, with a
year on each host. The apple phase is easily recognized on the
leaves and fruit by just about anybody who has grown apples. The
teliospore phase on the cedars is quite striking but is noticed much
less frequently. Fungicides in spray programs do a good job of
controlling the apple phase, while the cedar phase is best
controlled by buying resistant varieties. Some homeowners cut the
galls off before they break out into the "orange blob," but the
result is the same: You're going to likely lose the tips on those
branches.
Master Gardener plant sale
The Logan County Master Gardeners will have their
annual plant sale on Saturday, May 1, from 9 a.m. to noon at the
Logan County Fairgrounds exhibition buildings. The group members
have been working hard to get ready, so check out their offerings if
you have a chance.
[By
JOHN FULTON,
University of Illinois Extension, Logan County] |
