UMass
Extension Landscape Message #12
May 19, 2006
The
LANDSCAPE MESSAGE is an educational newsletter intended
to guide landscape, nursery and urban forestry professionals
in identifying pests in the landscape, monitoring their
development, planning management strategies and creating
site-specific records for future management reference.
UMass
Extension has updated this issue to provide timely
pest management information and the latest regional news
and environmental data throughout Massachusetts. The
next update will be available on Friday,
May 26, 2006.
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Message Archive.
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ENVIRONMENTAL
DATA
The following growing-degree-day (GDD) and precipitation
data was collected for a one-week period, May 11, 2006 through
May 17, 2006. Soil temperature and phenological indicators were
observed on May 17, 2006. Accumulated GDDs represent the heating
units above a 50° F
baseline temperature collected via our instruments since
the beginning of the current growing season. This information
is intended for use as a guide for monitoring the developmental
stages of pests in your location and planning management
strategies accordingly.
| Region/Location |
2006 GROWING DEGREE DAYS
|
Soil
Temp
(°F
at 4" depth) |
Precipitation
(1-Week
Gain) |
1-Week
Gain |
Total
accumulation for 2006 |
| Cape Cod |
20 |
134 |
52° |
4.85" |
| Southeast |
10 |
165 |
58° |
5.75" |
| East |
~15 |
~192 |
n/a |
n/a |
| Central |
3 |
131 |
45° |
4.23" |
| Pioneer Valley |
7 |
216 |
58° |
3.23" |
| Berkshires |
33 |
157 |
51° |
3.19" |
AVERAGE |
14.7 |
165.8 |
54° |
4.25" |
n/a = information
not available |
REGIONAL
NOTES
Cape
Cod Region (Barnstable) - General
Conditions: It feels like it has been raining for forty
days and forty nights but in reality, it has only been five days.
The Cape rainfall totals range from 5 inches in Falmouth to 3.5
inches in Chatham. We are appreciative of our well-drained, sandy
soils which keep most landscapes from becoming water logged. Plants
in the landscape look good, and the weeds are growing quite well
also. Many spring flowering shrubs and early perennials are providing
color. Pests/Problems: Dogwood bracts are severely
spotted and deformed on some native dogwoods. This could be caused
by one of several different fungi and is directly related to all
the moisture. We can expect this to be a good year for leaf spots
and blights. Be on the lookout for apple scab on crabapple, black
spot on rose, and other foliar diseases. Winter moth caterpillars,
eastern tent caterpillars, forest tent caterpillars, and gypsy
moth are all feeding freely on foliage at this time. Falmouth has
high populations of both winter moth and forest tent, while Mashpee
has many webs from the eastern tent caterpillar. Parts of the Route
6A corridor have silver maples that are defoliated from winter
moth. Norway maple leaves are starting to look like Swiss cheese.
Eastham reports high numbers of gypsy moth caterpillars, as well
as winter moth. Lily leaf beetles are active. Mosquitoes are making
their presence known. Deer tick nymphs will be active in the very
near future. As this is the stage most implicated in transmitting
Lyme disease, extra caution and thorough tick checks should be
undertaken.
Southeast
Region (Hanson) - General Conditions: Cool, wet weather
prevailed this past week with heavy rain almost every day. Areas
north of Plymouth County reported heavy flooding and received
higher rainfall amounts. Hanson received 5.75 inches of rain
this past week. Wisteria, Fothergilla, Halesia,
flowering dogwood,
Helleborus foetidus, Vinca, Pulmonaria, Trillium, Corydalis
lutea, anemones, Royal azalea, Bleeding heart, Euphorbia
polychroma,
Brunnera macrophylla, Epimedium, Phlox
subulata, Phlox divaricata,
Phlox stolonifera, Sweet woodruff, Columbine, Barberry,
and Soloman's Seal, are in full bloom. Dicentra eximia is
beginning to bloom. Pearlbush, Mayflower viburnum, Eastern redbud, Pieris
floribunda (Mountain Pieris), Pieris 'Brouwer's
Beauty, Helleborus
orientalis,
tulips and daffodils, are ending bloom. Lawns are green and in
need of mowing. Pests/Problems: The Plymouth County
Extension office continues to receive reports of small gypsy moth
caterpillars causing skin irritation after being found on the arms,
legs, and necks of people outside in the landscape. Gypsy moth,
eastern tent, forest tent, and winter moth caterpillars, hemlock
woolly adelgid, lily leaf beetles, wasps and hornets, carpenter
bees, mosquitoes, mayflies, and ticks are all active. Winter moth
caterpillars are feeding on a wide range of deciduous material
and were observed webbing the flower buds of lilac together and
feeding. Winter moth caterpillars were also feeding heavily on
roses along with gypsy moth caterpillars. Ground ivy, chickweed,
violets, and dandelions are in full bloom. Poison ivy is showing
up in the landscape; new growth is often a reddish-green. With
all the rain the past week, we've seen an increase in the orange
jelly-like galls of cedar-apple rust on eastern red cedar. One
tree looked like it was decorated for Halloween. Beneficial insects
are active.
East
Region (Boston) - General Conditions: No report
Central
Region (Boylston) - General Conditions: No report.
Pioneer
Valley Region (Amherst) - General Conditions: The
prolonged rainy periods during the last week knocked petals
off many flowering trees and shrubs. However, lawns are deep
green but soggy, while the dandelions go to seed. In the gardens
as the last of the tulips fade, leaves on hostas and fronds
on ferns unfurl, and columbines burst into bloom. Pests/Problems: Leaf
spot and shoot blight diseases are showing up on a number of woody plants. In
addition, forest tent and eastern tent caterpillars are abundant on the UMass
campus.
Berkshire
Region (Great Barrington) - General Conditions: Soggy! Pests/Problems: Cool
temperatures and heavy rains have slowed insect development, but
the following were observed this week. Tents of eastern tent caterpillars
are abundant, especially on wild black cherry. (I observed a Baltimore
Oriole poking its head into a ETC tent and removing and devouring
several caterpillars.) Snowball aphids are causing the curling of
leaves on scented viburnums, i.e., V. carlesii and V.
burkwoodii. Despite cool weather, mosquitoes are active though
few in number. European pine sawfly continue their development while
feeding on needles of mugo pine.
PHENOLOGY
The phenological indicators are a visual tool for
correlating plant development with pest development. The following
are the indicator plants and the stages of bloom observed
for this period:
Indicator Plants - Stages
of Flowering (begin, full, end) |
PLANT NAME (Botanic/Common) |
C.C. |
S.E. |
EAST |
CENT. |
P.V. |
BERK. |
|
|
| Syringa meyeri (Meyer Lilac) |
* |
* |
* |
begin |
begin |
* |
| Rhododendron ‘Exbury’ (Exbury
Azalea) |
begin |
begin |
* |
* |
begin |
* |
| R. catawbiense (Catawba Rododendron) |
begin |
* |
* |
begin |
begin |
begin |
| Aesculus hippocastanum & rel.
sp.(Horsechestnut) |
begin |
begin |
* |
begin |
full |
b/full |
| Syringa vulgaris (Common Lilac) |
begin |
full |
* |
full |
full |
full |
| Kerria japonica (Japanese
Kerria) |
b/full |
full |
* |
full |
full |
* |
| Elaeagnus umbellata (Autumn
Olive) |
* |
full |
* |
full |
* |
* |
| Lonicera tatarica (Tatarian
Honeysuckle) |
* |
full |
* |
* |
full |
full |
| Sorbus spp. (Mountainash species) |
* |
* |
* |
full |
* |
* |
| Cornus florida (Flowering
Dogwood)–bracts |
full |
full |
* |
full |
f/end |
full |
| Halesia spp. (Silverbell) |
* |
full |
* |
end |
full |
full |
| R. carolinianum (Carolina
Rhododendron) |
full |
full |
* |
* |
end |
* |
| Rhododendron spp. (early
Azaleas) |
b/full |
f/end |
* |
full |
full |
full |
| Malus spp. (Crabapple) |
full |
end |
* |
full |
f/end |
full |
| Cercis canadensis (Redbud) |
full |
end |
* |
full |
full |
full |
| Prunus x cistena (Purpleleaf
Sand Cherry) |
full |
* |
* |
* |
* |
f/end |
| Prunus serotina (Black
Cherry) |
* |
end |
* |
end |
f/end |
* |
| Pieris japonica (Japanese
Pieris) |
f/end |
end |
* |
* |
f/end |
* |
| Viburnum spp. (early,
fragrant Viburnums) |
f/end |
end |
* |
end |
end |
full |
| Chaenomeles speciosa (Floweringquince) |
f/end |
end |
* |
f/end |
end |
end |
| Spiraea prunifolia (Bridalwreath
Spirea) |
end |
end |
* |
end |
* |
* |
* = no activity
to report/information not available |
CAPE
COD REGION - Roberta Clark, Horticulturist for Barnstable County,
Barnstable.
SOUTHEAST REGION - Deborah Swanson, Horticulturist for UMass Extension
in Plymouth County, Hanson.
EAST REGION - James R. Allen, Horticulturist and Greenhouse Manager
for UMass Biology Department, Boston.
CENTRAL REGION - Joann Vieira, Superintendent of Horticulture, Tower
Hill Botanic Garden, Boylston.
PIONEER VALLEY - Dan Gillman, Plant Pathologist, UMass Extension
Plant Diagnostic Lab, UMass, Amherst.
BERKSHIRES - Ron Kujawski, Specialist, UMass Extension Landscape,
Nursery & Urban Forestry Program, Amherst.
WOODY
ORNAMENTALS
INSECTS
The past week of continuous overcast skies, low
temperatures, and immense amounts of rain, greatly slowed the activity
of many insect pests but has done little to reduce their numbers.
Now that sunnier days and higher temperatures are in the forecast,
renewed activity of these insects is fully expected. Many of the
caterpillar species are nearing maturity, and much defoliation
injury will most likely become apparent very soon. For many of
the lepidopteran caterpillars that have been active during the
past few weeks, it is most likely too late, statewide, to be using
B.t. Therefore, other options should be considered when treatments
are necessary.
Lepidopteran Caterpillars:
-
Winter
moth -
caterpillar is now large enough to be seen with the naked eye, and it is feeding
on expanding (and fully expanded) foliage. Damage is now becoming apparent. Monitor
for holes in the foliage and the green inchworms. This pest is once again in
large numbers in much of eastern MA and most of RI. Common hosts are maples,
crabapple, apple, birch, oaks, and many other deciduous hosts. Feeding will continue
until approximately the end of May, depending on the weather. During the spring
of 2004, winter moth began pupation around May 22; but last year, which experienced
cooler temperatures, winter moth was actively feeding into the first week in
June. So far this year, we are expecting that winter moth will pupate around
the end of May or during the first week in June. Choices for management now are
a Spinosad product or one of the registered and labeled chemical insecticides.
It is now too late for B.t.K. to be effective given the age of the caterpillars.
-
Fall
cankerworm has begun its activity but remains
rather small and really won’t become
a noticeable threat until winter moth caterpillars are fairly mature. This pest
will continue to feed into June. Fall cankerworm is usually green but does become
very dark when in large population numbers. Where winter moth has only two pairs
of prolegs, fall cankerworm has a partial third pair (most anterior pair), which
distinguishes it from winter moth. It is said that fall cankerworm has two and
a half pairs of prolegs. Oaks are the preferred host, but it does have a rather
wide host plant range. Controls are the same for this pest as they are for winter
moth.
-
Eastern
tent caterpillar (ETC) remains very active
now, and their silken webs in the crotches of branches
are very noticeable; in most cases there are multiple
webs per tree. Defoliation is already apparent in many
places. This will be one more outbreak year for ETC in
MA and many surrounding states. Feeding will continue
on Malus and Prunus until
late May or early June. Once the larvae mature, they can be seen crawling across
the ground, roads, etc. in search of a sheltered pupation site. It is too late
for B.t.K. to be effective, but the other registered controls that are labeled
for lepidopteran caterpillars should all work well at this time. Right now in
the Amherst area, eastern tent caterpillars have become quite large.
-
Forest
tent caterpillar (FTC) is very active statewide
and is feeding on foliage. This pest also has a wide
host range, but in western MA they are mostly on sugar
maple and some oaks. In eastern MA, this pest is primarily
found on oaks. Much defoliation is expected once again
from this pest. Control measures are the same as listed
above. This species does not make a noticeable silken
web, but they are often seen during the day huddling
together in very large clusters along the trunks and
branches of the host plant. In western MA, this caterpillar
is already an inch long, and defoliation is becoming
apparent. Some trees are draped with silk along the trunks
and branches. Feeding will continue into June, and this pest will achieve a final
caterpillar size of almost three inches. At that point, they are voracious feeders.
In eastern MA where it has been cooler, these caterpillars are currently much
smaller than those in the western parts of the state. It is now too late for
B.t.K. for FTC.
-
Gypsy
moth eggs have hatched across the state
now. The very tiny and hairy caterpillars have been blowing
around on silk in search of an acceptable tree to feed
on. Deborah Swanson in Plymouth County has started receiving
numerous calls from nursery workers and landscapers that
have experienced these tiny caterpillars landing on their
neck and other areas of exposed skin. In most cases,
very itchy and annoying rashes result from the urticating
(irritating) hairs of these caterpillars. Some people
are so sensitive that they develop “hay fever-like” reactions
from exposure to this caterpillar with symptoms such as itchy and watery eyes
to sneezing and runny noses. Those with severe reactions may need to consult
a physician.
-
Larch
casebearer resumed activity as soon as the
buds started to open on their host plants (larch). These
tiny caterpillars overwintered within needle tips (their
case) on the trunks and branches and have now moved out onto
the foliage and are actively feeding at the needle tips.
A Spinosad product or one of the registered chemical insecticides
will work well now if deemed necessary. Parasites usually keep this pest in low
numbers; therefore, it is best to use a product that has the least effect on
these beneficial organisms.
Hymenopteran Caterpillars (Sawflies):
- European pine sawfly has become
active. Eggs, in the form of blocky yellow patches, started
to appear within the last two weeks, and caterpillars
began to hatch in the warmer regions more than a week
ago. Feeding injury is beginning to appear. These caterpillars
become voracious feeders as they grow and are capable
of consuming large amounts of foliage daily. Monitor
for their presence now, and treat the very young caterpillars
with an insecticidal soap or a product that contains
Spinosad or use one of the registered
chemical insecticides. Mugo pine is one of the more common
hosts for this pest.
- Azalea sawfly is now active in
the warmer regions of the Amherst area, which currently
has accumulated more GDD’s than other parts of
the state. The coloration and posture of this caterpillar
on the plant (usually 'Exbury' and 'Mollis' azaleas =
deciduous) are so cryptic that much damage can be created
before it is noticed. Monitor for the appearance of feeding
damage that leaves nothing but the main veins. Then inspect
much more closely for the green caterpillars that hug
the margins of the foliage and that are almost the same
color as the foliage. Treat with a product that contains
Spinosad.
Beetles:
- Lily
leaf beetle
is
active. Inspect for the bright red adult beetles,
which are foraging and beginning to feed. Within
a few weeks, start to inspect the undersides of foliage
for short (about one inch long) irregular-shaped
tan-colored lines that are actually a row of eggs.
Once found, they can be removed and destroyed. Just
before these eggs hatch, they will turn orange and
then a deep red color. Nymphs, which won’t
appear for several more weeks, can be treated with a product that contains Spinosad.
Piercing-Sucking Insects and Mites:
- Spruce spider mite is active. Damage
in the form of fine yellow stippling that contributes
to an overall appearance of chlorosis has now become
obvious from last fall’s feeding. Monitor for these
two-toned (tan color) mites with a hand lens, and treat
if numbers appear to be high. Oil sprays (at the summer
rate) work well on all life stages, but take caution
with tender new foliage that is now emerging from the
buds. In such cases, it may be prudent to wait until
it has fully expanded to apply oil. Some of the newer
Mite Growth Regulator products can be quite effective
on the egg stage (ovicidal) and immatures of many spider
mite species (Tetranychidae) while not being harmful
to predatory mite species. Adult spider mites are often
not killed by exposure to these products, but exposed
female mites may produce inviable eggs.
- Hemlock eriophyid mite is active.
These tiny, peg-shaped and pale yellow mites are just
visible to the naked eye and can be seen feeding actively
on the needle surface. Large populations will lead to
much chlorosis and plant stress. Manage when found in
large numbers.
- Balsam twig aphid is active. The “Stem
Mothers” have been feeding and have now produced
many offspring that are capable of creating much feeding
injury in the form of needle distortion and much sticky
honeydew. True firs, such as Balsam and Frasier, are
most susceptible. High numbers of this pest can render
Christmas trees unfit for sale.
- Snowball aphid is active. Its preferred
hosts are certain viburnum species, such as Korean spicebush,
cranberry viburnum, mapleleaf viburnum as well as others.
When the aphids hatch they begin to feed with their piercing-sucking
mouths on newly expanding foliage, which causes severe
leaf curling and distortion. The aphids continue to feed
through the rest of April until about the end of May
within the confines of the curled leaves. Their feeding
does not kill the foliage nor does it create yellow-stippling
injury that is so typical to other piercing-sucking insects.
However, it can create so much leaf distortion that it
de-values the aesthetics of affected plant material.
Imidacloprid that is already systemic within the plant
from last summer works very well. Treating with a contact
insecticide offers little management given that these
aphids are so well hidden within the curled foliage.
In the Amherst area new leaves have already been affected
and, in most cases, it is too late for treatments.
- Larch adelgid is active and can be seen as white cottony masses scattered throughout the needles
of its host. When in large and very noticeable numbers, it should probably be
managed.
- Pine bark adelgid is active again,
and large populations can appear like wind-driven snow
on trunks and the undersides of scaffold branches of
white pine. Although very showy, it rarely requires treatment.
- Hemlock
woolly adelgid (HWA)
has
been producing crawlers for the past two to three
weeks, and they are now settled and feeding. The
crawler stage is a very dangerous time for this pest
to be moved from plant to plant or to different locations (by wind, birds, humans
or wildlife). Once settled, they begin to feed and then not be mobile again until
the next generation of crawlers in June. Oil sprays (summer rate) work very well,
but care should be taken to avoid applying oils when tender new foliage is appearing.
Systemically applied Imidacloprid is also effective, but translocation can take
anywhere from weeks to months to get to where this pest is feeding.
- Honeylocust
plantbug is active. The overwintering
eggs have been imbedded in the tender shoots, and
they hatched at bud break. The tiny, pale green nymphs are now feeding with their
piercing-sucking mouths on expanding foliage. When this pest occurs in large
numbers and the weather becomes cool for an extended period of time (many days
to more than a week), the injury can become great to tiny foliage to the point
where it never fully expands. During certain years, honeylocust can be defoliated
by this piercing-sucking pest. Monitor by shaking branches over a sheet of paper
and inspecting for the nymphs. When numbers are high, it may be prudent to treat.
Leaf Miners:
- Inkberry leafminer mines are obvious. Despite the larvae
being in the mines since early last summer, the browning of these mines has
only just occurred within the past month or two. Make note of plants with
noticeable infestations, and prepare to place yellow sticky cards out around
early-mid May to monitor for the emergence of the adult flies, which will
indicate the time to apply controls to break the cycle of re-infestation.
- Native holly leafminer mines are very obvious right
now on American Holly, but there is nothing to be done for management. Wait
until June to place out yellow sticky cards to monitor for the next generation
of adult flies, and treat at that time with a knockdown type spray such as
a pyrethroid.
- Birch leafminer -
Yellow sticky cards should now be placed out in susceptible birches where leaf
expansion has begun. Adult sawflies should appear around the time that the leaves
are half-emerged from the buds. Treat when the adults appear.
Gall Formers:
- Eastern
spruce gall adelgid is actively feeding
and about to stimulate new gall formation. In cooler
areas where bud break has not yet begun, oil sprays
at the summer rate can be very effective. Once galls
are formed, managing this pest is extremely difficult.
Norway and white spruce are two common hosts for this pest in MA.
- Cooley
spruce gall adelgid is also active on
blue spruce. Its biology, damage, and management
are very similar to that of eastern spruce gall adelgid.
However, bear in mind that oil sprays do remove the
blue color from blue spruce needles for at least
a few months.
Reported
by Robert Childs, Entomologist, UMass Extension Landscape,
Nursery and Urban Forestry Program, Amherst.
The
rainfall has given plants a good watering, but with leaves
developing, they are vulnerable to leaf spot
and shoot blight infections, especially when accompanied
by temperatures of 50-70 degrees F. This is the time to
apply protective fungicides to nursery and specimen woody
landscape plants.
Rhabdocline needle cast fruiting
structures are visible on infected Douglasfir needles. Symptoms
of Rhabdocline infection appear as elongated red-brown spots
and bands on infected needles. Spots often coalesce, and most
of the needle turns color except for the base, which remains
green. Infection tends to occur on the bottom of the tree first.
Infected needles drop prematurely from now into the summer.
Spores released from these fruiting bodies during cool, wet
weather infect new needles that will soon start developing.
Avoid overhead watering of Douglasfir at this time of the year.
Provide adequate spacing, and limit weed growth around young
trees. Consider fungicide applications to susceptible, high-value
trees if this spring is wet. Maintain protection during the
vulnerable period when the needles are first emerging from
buds until they expand to full size.
Sphaeropsis
(Diplodia) shoot blight on
pine can cause significant damage to stressed red,
pitch, Japanese black and, especially, Austrian pine
in our area. If wet weather continues, new shoots
developing on these trees are vulnerable to infection.
Consider applying fungicides to protect susceptible
trees as soon as buds swell significantly. Reapply
sprays at labeled intervals until the new growth
fully expands, if wet conditions persist. The Sphaeropsis
fungus produces significant amount of inoculum on
the outer scales of second-year cones, as well as
infected shoots and needles. Prune affected shoots
when plants are dry to improve appearance, but this
will make little difference in reducing inoculum
for new infections without cone removal, too. If
replacement of severely affected pines is an option,
plant trees resistant to Sphaeropsis shoot blight
as well as better adapted to grow on the site.
Gymnosporangium rust fruiting
structures are visible on eastern red cedar (really a juniper)
and Rocky mountain juniper, as well as the occasional Chinese,
common, creeping and savin juniper hosts. Specifically, cedar-apple
rust galls
are visible on eastern red cedar (really a juniper) as eruptions
of orange, gelatinous masses protruding from pea- to golf
ball-sized galls. These fruiting structures release spores
that infect apple and crab apple leaves at this time of the
year during cool, rainy periods. Likewise, fruiting structures
of hawthorn rust and quince rust are on many of these junipers,
but the fruiting structures are less conspicuous. Hawthorn
rust develops pea-size or smaller galls while the quince
rust fruiting structures emerge as red-orange “cracks” in
the bark of infected branches. Leaves, green shoots, and fruit of serviceberry,
hawthorn, mountain ash, quince, flowering quince, and pear, as well as apple
and crabapple are susceptible broadleaf alternate hosts.
Sycamore, maple, oak, and ash anthracnose are
evident now as dark-green to dark-brown curling leaves and
shootssycamore, maple, and oak, while ash
anthracnose appears as young green leaves with very tiny brown
spots falling from the trees. Anthracnose is widespread on
early leaves and shoots this year due to the abundance of inoculum
on overwintering twigs and fallen leaves, as well as the consistently
wet weather. These diseases cause some premature leaf loss,
but that is not going to seriously damage an otherwise healthy
tree. In the fall, fine prune infected twigs if practical,
as well as collect and dispose of fallen leaves. Promote drying
of foliage by pruning and spacing plants to increase the penetration
of sunlight and air circulation in and around plants.
Phomopsis
tip blight - The
current wet conditions, along with the development of immature
scale-leaves/needles are favorable for infection of juniper
by Phomopsis tip blight. Juniper shoots that are tan-gray
with pinhead sized, black fruiting bodies are producing
spores at this time. New growth that becomes infected this
spring with Phomopsis tip blight will turn green-yellow,
then brown, and die within a few weeks of infection. Management
begins with the removal and disposal of infected shoot
tips when they are dry to reduce inoculum. Cut an inch
or so below the boundary between dead and healthy tissue.
Now is the time to initiate fungicide control of juniper
tip blight to improve plant appearance. Grow junipers in an
open, sunny location to promote drying of foliage, that are
adapted to the site and that have resistance to tip blight.
Dogwood
anthracnose fruiting
structures are apparent on trees where there are buds that
did not open as well as twigs and branches that died back.
Water shortage, heat stress, compacted soil, and winter
damage weakens trees and increases the severity of the
disease. Dogwoods receiving good cultural care are better
able to limit the extent of dogwood anthracnose damage.
Water during dry periods and maintain 2-4 inches of composted
bark mulch over as much of the root area as possible. Prune
off and dispose of diseased twigs and branches to reduce
anthracnose inoculum in the tree. High value trees benefit
from four fungicide applications to control dogwood anthracnose
during wet seasons. Begin, as buds break open, reapply
when bracts have fallen, and again four weeks later. A
fourth application in late summer protects flower buds
if there is wet weather after they form. If this is a persistent
problem, consider planting one of the many resistant cultivars
of C. florida and C. kousa now commercially
available.
Ramorum Blight, also known as Sudden
Oak Death (SOD) - Since the early 1990’s,
oaks and tanoaks were dying in the coastal counties of California.
Since then, other types of plants have been found to be infected
or associated with this disease, referred to as Sudden Oak
Death, ramorum leaf blight or ramorum dieback, or by regulation
as Phytophthora ramorum. The first
positive identification of the disease was in 1995 on tanoak
in Mill Valley (Marin County), California. Since that time,
surveys confirmed Phytophthora ramorum on various
native hosts and nursery plants in several locations in California,
Oregon, Washington, and British Columbia. When nursery surveys
find infected plants, prompt quarantine and/or eradication
activities ensue. Research conducted by the Agriculture Research
Service, US Forest Service, universities, and others is under
way to better identify hosts, improve methods of detection,
and develop effective treatments. USDA APHIS currently regulates
84 plants, two of which are at the genus level (Camellia and Rhododendron).
There are no chemical treatments currently available to eliminate Phytophthora
ramorum from infected plants.
Status of Phytophthora ramorum Monitoring
Surveys .
The 2006 National Nursery Survey is likely just getting underway.
In past years the survey visited nurseries and collected samples
from host plants exhibiting leaf spot, blight, and canker symptoms
associated with Phytophthora ramorum infections.
Dan
Gillman, Plant Pathologist, based in the UMass Extension Plant
Diagnostic Lab at UMass, Amherst.
WEEDS
Garlic mustard is flowering now
and should be controlled now before seed is produced. Garlic mustard
is a biennial, therefore control now will also control first-year
seedlings and second-year plants before they go to seed. A non-selective
translocation or contract herbicide can be used.
Continue the treatment
of winter annuals and perennials in ornamental beds with glyphosate
or glufosinate. It is too late to have good control with many
of the non-herbicide materials that containing clove oil, citric
acid, or acetic acid. Preemergence herbicides can be applied to
weed-free ornamental beds now.
Randall
Prostak, Weed Specialist, UMass Extension Landscape, Nursery,
and Urban Forestry Program, Amherst.
TURFGRASS
Insects:
Spring Conditions and Insect Management.
The weather is dominating the news this week. The eastern end
of Massachusetts (and southeastern New Hampshire) have been inundated
with rain, but many areas in central and western Massachusetts
also got more than four inches of rain and are facing varying
degrees of flooding.
This is a quick note to mention that we cannot
expect the flooding to reduce insect problems. It may move the
insects, but many of them seem to be able to handle being submerged
for several days. Last October we sampled turf areas that had
been underwater for almost three weeks and found very healthy
European chafer grubs peering back at us. We do often see annual
bluegrass weevil larvae floating in puddles after an area has
been underwater, and they follow the "fall line." They
may move, but most of them won't die.
Remember, don't apply any
pesticides or fertilizers when the soil is saturated. We'll
have to wait until things dry out and then reassess where we
are.
Pat
Vittum, Professor, Department of Plant, Soil, and Insect Sciences,
UMass, Amherst. Weeds:
Forsythia is done flowering, and preemergence applications should
be completed by now. The cool, rainy weather will allow a little
extra time. If you still need to apply preemergence herbicides,
the best treatment now is sprayable dithiopyr since dithiopyr
can effectively control one and two-leaf crabgrass.
Dandelion, violet, and ground ivy are
in flower but should not be treated yet; wait until they are
done flowering.
Bluets are still in flower. This “flowering
weed” indicates low soil pH. Check these areas for low
pH, and lime as needed.
Wild garlic in noticeable now.
Ignore it and it will go away, or treat with a broadleaf turf
herbicide. Control is increased if weed is stepped-on or rolled
before application. Granular formulation should not be used.
Randall
Prostak, Weed Specialist, UMass Extension Landscape, Nursery,
and Urban Forestry Program, Amherst.
2006 UMass Green School to Start October 31 in Milford,
MA
Green School is a comprehensive certificate training program
for Green Industry professionals taught by UMass Extension Educators
and Faculty. This course is designed for landscape, turf, and
other horticultural practitioners wishing to gain an understanding
of horticulture fundamentals and strategies and their relation
to environmental quality. Green School attendees learn about
sustainable approaches to turf and landscape management in managed
environments. Green School's curriculum is based on research
and information emphasizing environmental stewardship and integrated
pest management (IPM). Participants develop an understanding
of how proper management practices impact natural resources such
as soil and water. Participants learn to make environmentally
appropriate decisions related to turf and plant selection, plant
maintenance, pest and nutrient management.
The 2006 schedule and
application form will be posted on www.umassgreenfino.org in
June.
Scouting for Pests and Problems of Turf and Woody Ornamentals,
5:00-7:00 p.m.
May 30, 2006 - Springfield, MA
June 1, 2006 - Wellesley, MA
June 15, 2006 - Bridgewater, MA
Learn how to put IPM practices to work efficiently. Join
us in a walk through the landscape for demonstrations of IPM tools
and techniques, as well as a close look at some of the most common
cultural problems and troublesome insect, mite, and disease problems.
Workshop held rain or shine. Two Pesticide contact hours for
categories 29, 36, 37, and Applicators License available.ISA,
MCA, MCH, and MCLP credit requested. See our Conferences & Workshops
page for registration information.
July 19, 2006 - Nursey
& Landscape Summer Meeting & Trade Show - The
day will offer horticulture education workshops presented by
well known researchers and educators, a trade show and hands-on
insect, disease, and weed laboratory. At press time, plans were
underway to feature an actual outdoor set-up of garden center
displays showing examples of today’s most successful marketing and
plant branding strategies. Plans to organize class reunions for
Stockbridge School of Agriculture and UMass alumni the day before
and have University Admission officials on hand to answer questions
about student applications are also in discussion.
This special
event will also showcase
Dr. Michael A Dirr, respected author, lecturer and retired Professor of Ornamental
Horticulture from the University of Georgia, Athens as keynote speaker. Dr. Dirr
will give a presentation on Breeding, Evaluating, Introducing
and Marketing New Woody Plants. Professor Dirr has had a long
and varied career since he received his Ph.D. in Plant Physiology
from the University of Massachusetts, Amherst, in 1972. Before
moving to Georgia he held appointments at the University of Massachusetts,
the University of Illinois, Urbana, and the Arnold Arboretum
of Harvard University.
You
will want to mark your calendars now. For more information, go
to http://www.mnla.com
, http://www.umassgreeninfo.org,
or contact UMass Extension’s Landscape, Nursery and Urban
Forestry Program at (413) 545-0895, eweeks@umext.umass.edu. Time: 9
AM to 3:00 p.m. Location: UMass Amherst Student Union and Metawampe
Park.
IMPORTANT
INFORMATIONAL RESOURCES
2006 UMass Extension Green Directory: Now Available!
The 2006 UMass Extension Green Directory is a comprehensive guide
to educational resources for Massachusetts Agriculture industry
professionals. This 25 page guide is used as a reference document
all year long! To receive a copy, send mailing address: email
greeninfo@umext.umass.edu;
fax requests to 413-577-1620. The complete directory is also available
online in PDF format. Visit http://www.umass.edu/agland
and click 'The Green Directory' link in the right hand menu.
Two UMass Extension Web Sites are specially
designed to provide Green Industry professionals with resources,
upcoming educational programs and events, and other relevant information.
The Internet address for the Landscape, Nursery, and Urban Forestry
Program is http://www.umassgreeninfo.org.
The Turf Program address is http://www.umassturf.org
.
Don't forget to visit the UMass
Extension Online Weed Herbarium!
The freshly revised 2006-2007 Professional
Guide for IPM in Turf for Massachusetts features
the latest techniques critical to environmentally sensitive,
integrated management of lawns, athletic fields, and golf courses.
The guide, intended for use by professionals, presents research-based
material regarding turfgrass selection and water conservation,
as well as current approaches for managing disease, insect,
weed, and nematode problems. Municipal and school officials
charged with establishing IPM programs in their communities
and gardeners and homeowners serious about sensibly caring
for their properties will find unique and critical information
in the guide as well.
The 2006-2007 Professional
Guide can be used effectively in a wide range of management schemes:
from organic, to low-maintenance, to high-intensity care of high-use
turf. Alternative and cultural pest control options are highlighted,
and pesticide selection advice is based on least environmental
impact. While certain portions of the guide are specific to Massachusetts,
much of the information is applicable throughout New England.
Initially developed in 1991, this revision for 2006-2007 marks
the 8th edition of this popular publication.
To obtain a copy,
order online from the Outreach Bookstore (http://umassoutreachbookstore.com );
or call the UMass Outreach Bookstore. The phone number is (413)
545-2717. In either case, payment may be made by credit card.
Alternatively, you may visit the UMass Outreach Bookstore during
normal business hours; Monday through Thursday from 9AM-3PM,
closed Friday. The bookstore is located in Draper Hall on the UMass
campus.
UMass Extension’s Turf Management Guide
and IPM Facts: For more information about the turf pests
mentioned in this message, you will need to refer to the following
publications: the freshly revised Professional
Guide for IPM in Turf for Massachusetts, 2006-2007
edition and Turf
IPM Facts .
Call (413) 545-2717 to order these publications from the UMASS
Outreach Bookstore 
DIAGNOSTIC
SERVICES
UMass Laboratory Diagnoses for Turf and
Landscape Problems - Accurate
diagnosis for a turf or landscape problem can often eliminate or
reduce the need for pesticide use. The UMass Extension Plant Diagnostic
Lab is available to serve commercial landscape contractors, turf
managers, arborists, nurseries and other green industry professionals.
It provides woody plant and turf disease analysis, woody plant
and turf insect identification, turfgrass identification, weed
identification, and offers a report of pest management strategies
that are research based, economically sound and environmentally
appropriate for the situation. Send specimens and payment (payable
to the University of Massachusetts) to UMass Extension Plant Diagnostic
Lab, Holdsworth Natural Resources Center, 160 Holdsworth Way, UMass,
Amherst, MA 01003. The fee for a woody plant disease analysis is
$50; the fee for turf disease analysis or nematode assay is $75.
All insect, weed and turfgrass identification samples are $25 each.
For more detailed submission instructions see http://www.umass.edu/agland/diagnostics 
NEXT UPDATE: The next issue will be available
on Friday, May 26, 2006.
This
message is produced by the UMASS Extension, Landscape, Nursery
and Urban Forestry Program. The copy is prepared by Anna Greene
from data and reports provided by the staff and faculty of the
UMass Landscape, Nursery and Urban Forestry Program and the UMASS
Extension Turf Program as well as cooperating horticulturists
and Green Industry professionals. The text is adapted for access
via the internet by Jason Lanier and made available to subscribers
via electronic transmittal by Ellen Weeks.
DISCLAIMER.
This message is intended for commercial use. UMass Extension assumes no liability
for recommendations. It is the responsibility of the applicator to verify the
registration status of any pesticide BEFORE applying it. Different states have
different regulations as well. The use of trade names (*) does not imply endorsement.
Similarly, there may be other products you prefer to use.
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or suggestions in regard to the Landscape Message? Please e-mail
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