|
Anthracnose of Shade Trees
Anthracnose is the common
name for a type of leaf spot and canker disease caused by certain
kinds of fungi. Anthracnose diseases affect many trees, but are particularly
prevalent on white oak, ash, maple, walnut and sycamore. Each species
of tree is infected by a different species of fungus, thus the fungus
does not spread from oak to maple or maple to ash or ash to sycamore.
A different fungal species is also responsible for dogwood anthracnose.
Symptoms are especially
severe in years with cool, wet spring weather. The symptoms will
vary depending on the type of tree and the stage of plant development
at the time of infection: leaf spots or blotches, twig dieback and
wilting, and browning or death of emerging leaves are all possible.
Premature leaf drop often occurs with anthracnose diseases, however,
most of the trees infected with anthracnose usually show good resilienc,
and are not permanently damaged by this early season leaf blight.
Full Story, http://www.extension.purdue.edu/extmedia/BP/BP_9_W.pdf
Bagworms
Bagworms have just hatched in Central Indiana and are likely to
defoliate many arborvitae and juniper over the next six to eight
weeks. Fortunately homeowners have many control options at their
fingertips to save their plants. Two of these control options, spinosad
and BT, can kill the bagworms without triggering spider-mite problems.
Visit the links below for details on control options and how to
identify this pest.
http://www.entm.purdue.edu/entomology/ext/targets/e-series/EseriesPDF/E-27.pdf
Four-lined Plant Bug
Four-lined plant bugs are common pests in gardens and landscapes
this time of year. Feeding injury from these insects appears as
small (1/16 inch), sunken round spots on young foliage of many herbaceous
and woody plants.
http://www.ppdl.purdue.edu/PPDL/weeklypics/Weekly_Picture5-21-01-2.html
Peach Leaf Curl
Thanks to our cool, wet spring weather, peach leaf curl is now appearing
in some peach and nectarine trees. Symptoms are quite distinctive
and look like portions of the leaf have "ballooned" out.
These distorted portions often are colored a bright pink to red
and may be thickened, puckered, and curled.
http://www.ppdl.org/dd/id/peach_leaf_curl-peach.html
Maple Petiole Borer
The symptom is curled leaves. Examination of the petiole reveals
a hollow hole. This borer is a sawfly that has one generation a
year. Though many leaves can be lost in a single year, there is
no detrimental damage.
http://www.ppdl.purdue.edu/PPDL/weeklypics/Weekly_Picture5-7-01-3.html
For
more insect, pest or disease stories, go to:
http://www.extension.purdue.edu/gardentips/insects.html
|
