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UMass Extension Landscape Message #12
May 19, 2006

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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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Interested in additional turf-oriented content? UMass Extension Turf Program Management Updates External link

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 Adobe PDF icon 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) Adobe PDF icon 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.


DISEASES

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 Adobe PDF icon 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 Adobe PDF icon 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 Adobe PDF icon - 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 Adobe PDF icon 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

Diseases: No report: Visit the Landscape Message Archive for previous messages.

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.

UPCOMING EVENTS

For a complete listing of upcoming events, see our Conferences and Workshops page.

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 External link, 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 External link 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 External link.

Don't forget to visit the UMass Extension Online Weed Herbarium!

The freshly revised 2006-2007 Professional Guide for IPM in Turf for Massachusetts External link 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.comExternal link); 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 External link edition and Turf IPM Facts External link. Call (413) 545-2717 to order these publications from the UMASS Outreach Bookstore External link

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 External link


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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