TPM/IPM Weekly Report

Transcription

1 TPM/IPM Weekly Report for Arborists, Landscape Managers & Nursery Managers Commercial Horticulture March 9, 2012 In This Issue... - Welcome Back/Weather - Sad News - Horticultural oil - Euonymus leaf-notcher caterpillar - Fiorinia scale - Japanese cedar longhorned beetle - Nursery survey - Boxwood blight - Invasive species training - Black knot on cherry - Eastern tent caterpillar - Hemlock woolly adelgid - Spruce spider mite - Anthracnose - Emerald ash borer Weed of the Week Phenology Degree days Conferences Integrated Pest Management for Commercial Horticulture Coordinator Weekly IPM report: Stanton Gill, Extension Specialist, IPM for Nursery, Greenhouse and Managed Landscapes, sgill@umd.edu (office) or (cell) Regular Contributors: Pest and Beneficial Insect Information: Stanton Gill and Paula Shrewsbury (Extension Specialists) and Brian Clark (Extension Educator, Prince George s County) Disease Information: Karen Rane (Plant Pathologist) and David Clement (Extension Specialist) Weed of the Week: Chuck Schuster (Extension Educator, Montgomery County) Cultural Information: Ginny Rosenkranz (Extension Educator, Wicomico/ Worcester/Somerset Counties) Fertility Management: Andrew Ristvey (Regional Specialist, Wye Research & Education Center) Design, Layout and Editing: Suzanne Klick (Technician, CMREC) Welcome Back Winter or Spring? (Stanton Gill) With 70 F degree weather it is hard to believe it is still officially winter. Since we really have not had much of a winter we are starting the weekly IPM report in early March rather than the end of the month as we do most seasons. Many plants have swollen flower buds at this point and we are seeing early cherry varieties in bloom and daffodils in several sites are wide open. The brown marmorated stink bugs, greatly reduced in numbers in 2012, are starting to crawl around and get active with the sunny, warm weather. Last fall I wrote an article announcing that a new synthetic pyrethroid that was different from other pyrethroids was now labelled for use in houses to control BMSB. This material is sold under the name Demand. If you work for a commercial horticultural business in the area, you can report insect, disease, weed or cultural plant problems found in the landscape or nursery to sklick@umd.edu We are about 3 weeks early with bloom development compared with previous years. The cherry blossoms are predicted to be in full swing from March 21st to March 30th. This year marks the 100th anniversary of the cherry blossoms. The National Park Service is planning several weeks of celebration in Washington this year to commemorate the occasion. We have had several nursery growers apply their dormant horticultural oil applications during the frequent periods of 4-5 days when temperatures have been above 50 F. We placed out the ambrosia alcohol baited taps at several locations in late February. We have not found any ambrosia beetles yet, but we will let you know when we see ambrosia beetle activity. If your customers

2 have peach trees and they want to prevent peach leaf curl, then you need to put on a fixed cooper application this week. We have a very small window in which this preventative application can go onto the trees to prevent the disease symptoms from showing up later in the season. Sad News We received news that Steve Castrogiovanni, Maryland Arborist Association president, was involved in an accident on Tuesday this week. He was working on setting up the MAC-ISA workshop when he fell 60 ft from a tree. He is in critical condition at Suburban hospital. Our hopes are with him and we hope there is good news coming on his recovery. Horticultural Oil Back in January, I (Stanton) started getting calls from nursery owners asking if it was ok to apply dormant oil rates to nursery plants since we had several periods of 50 F weather for 3 or 4 days in a row. My answer is sure go ahead. I asked other entomologists their thoughts on winter applications of oil. Most entomologists agreed it was fine. David Sheltar, Ohio State University, noted that he has recommended oil sprays to nursery and C-tree producers any time the weather is warm enough for the sprays to hit, spread and dry before any chance of a freeze event can occur. Dave Shetlar s biggest concern in Ohio is application technique. Many of the nursery operations and C-tree growers have mist blowers that are generally inadequate for applying oil emulsion sprays correctly (unless they go every other row!). He also noted that older oil data indicate that only a certain set of armored scales are controlled by true dormant oil applications. Generally, the scales that overwinter as immatures or adults that are not fully encased in a waxy test (covering) are pretty well controlled. However, scales that overwinter as eggs usually have poor results though it is obvious that some of the eggs are contacted (primarily through capillary action) and killed. Most soft scales are knocked out as well as are the eggs of a variety of mites and leps that attach eggs as singles or single layers. Euonymus Leaf-notcher Caterpillar (Pryeria sinica) The euonymus leaf-notcher caterpillar is active very early in the season. Since this winter has been unusually warm, look for eggs and early instars of this caterpillar now. In recent years, MDA has been monitoring sites in Anne Arundel County where this species has been found in Maryland. MDA reported a lower number of egg masses last year compared to previous years. If you see this caterpillar in other areas, please let MDA know. Control: Since the damage occurs early in the season control is not always necessary. There is only one generation of this pest and plants can recoup. If you decide to treat, control options include Conserve (spinosad), Talstar (bifenthrin), and Orthene (acephate). Bt is effective only when the caterpillars are small. Late instar caterpillar of Pryeria sinica Note: There is another caterpillar, called the euonymus caterpillar (Yponomeuta cagnagella), that is active later in the season in May and June. Fiorinia scale (Fiorinia externa) Stephen Griner, Scientific Plant Service, submitted a hemlock sample with fiorinia scale (aka hemlock elongate scale). Crawlers of this scale are active later in the season and there are multiple overlapping generations until fall. Control: At this time of year, an application 3-4% oil can be used. 2

3 Japanese Cedar Longhorned Beetle (JCLHB) Bob Trumbule, Maryland Department of Agriculture We (MDA) are monitoring the situation with the Japanese cedar longhorned beetle in Maryland. We are surveying to determine where it is present in Maryland and what plant hosts it attacks. Recently, it was found in Cryptomeria and Leyland Cypress. This week, we have identified another JCLHB host that was in question: Juniperus scopulorum Moonglow. So far, JCLHB has been confirmed in Cryptomeria japonica, xcupressocyparis leylandii, and Juniperus scopulorum in Harford County Maryland. It was also confirmed in Cryptomeria japonica in Anne Arundel County, but it was most likely in material that was infested when it was installed. We still have not found it in other landscape plantings Damaged caused by Japanese cedar in Anne Arundel County so it might not be established there yet. longhorned beetles Areas of Cecil and Baltimore counties are also being surveyed for this pest. JCLHB has also recently been found in southeastern Pennsylvania. We are not sure yet if it is a primary pest or if it is a secondary pest that is attacking damaged, stressed or otherwise weakened trees. At this time Gaye Williams, MDA, is finding adult beetles in smaller diameter (1/2-1 ) branches, but not in main stems of infested trees. Sometimes only single limbs or branches are infested; other times it is most of the branches on a host. All of the plant material we found to be infested looked pretty bad. Cryptomerias and Leylands may have had winter cold, snow or drought/heat injury from , and have been predisposed to attack. We are still not sure if what we are seeing is the first or second year of infestation, but I would guess the latter, based on condition of the plants. We also looked at healthy Cryptomeria, Thuja, Chamaecyparis and native Juniperus virginiana in landscapes near the infestations and found no sign of dieback or infestation by JCLHB. Adult Japanese cedar longhorned beetles Prior to more recent confirmed movement, it was found at a nursery in Connecticut in 1999 in apparently healthy Thuja, and in 1997 it was found in a dead Juniperus virginiana in Manteo, NC. Nevertheless, it is important for landscapers and nursery growers to keep an eye out, and give us a call if they see anything suspicious. Adults will likely be flying in late March-Mid April. Growers, landscapers, arborists and IPM scouts can call MDA (BobTrumbule, ) if they see suspicious dieback. The bottom line is that this pest was not here until recently, and now appears to be on its way to establishment in parts of Maryland. Sustainability Practices in Nurseries Project Survey A survey was sent to individuals who have attended recent Extension and MNLA programs (September 25, 2008 Nursery Field Day at Raemelton Farm, October 2, 2009 Nursery Program at Snell s Nursery, June 17, 2010 MNLA Field Day at Homestead Gardens, and June 2011 MNLA Field Day at Priapi Gardens) at which research-based information on sustainability practices was provided. Some were ed the survey and others were sent a mailed copy. It will help us out a lot to get feedback on the educational efforts on sustainability in nurseries so please fill the out the survey. If you attended one of the programs listed above and do not recieve a survey by early next week, please let Suzanne Klick know at sklick@umd.edu and she will you the link. Thank you for your attention to this matter. 3

4 Boxwood Blight By now everyone has probably heard of the new boxwood blight disease caused by the fungus Cylindrocladium pseudonaviculatum. The disease was first identified in North Carolina and Connecticut in October 2011, and has now been confirmed in 9 states, including Maryland and Virginia. As the growing season gets underway, be on the lookout for the symptoms of this new disease. All types of boxwood are susceptible. Dark brown to black lesions on the stems are typical of boxwood blight infections. When leaves become infected, they turn brown and often have darker brown zone lines in the necrotic tissue. If you suspect you see symptoms of this disease, please send twigs and foliage (enclosed in double ziplock plastic bags) to the University of Maryland Plant Diagnostic Lab ( umd.edu). Boxwood infected with Boxwood blight, showing dark stem lesions and discolored foliage Photo: Karen Rane, UMD For more information and excellent photos of the disease, check out the pest alert from the Connecticut Ag Experiment Station: caes_disease_alert_boxwood_blight_ pdf Other diseases on boxwood include Macrophoma (2 leaves on left) and Volutella (3 leaves on right) Photo: David Clement, HGIC Invasive Species Training: March 21, 2012 at Carroll Community College This interactive one-day training session on invasive species will be very useful to each of you in the arborist, landscape and nursery business. The session is limited to the first 40 people to sign up. We have to limit the participation to keep this program hands-on. The location at Carroll Community College will be a new one for this training session and it is a beautiful facility that is easy to get into at the beginning of the day and easy to get out at the end of the session. A brochure is available at We hope to see you on March 21st - A great way to kick off spring. 4

5 Black Knot on Cherry Before cherry trees leaf out this spring, it is a good time to look for black knot on cherry since it is very easy to spot at this time of year. Black knot is caused by a fungus. The galls can be unsightly, but unless in very high numbers, usually do not kill the tree. The best thing to do is to prune out the galls before the trees leaf out to remove future inoculum. It is easy to see the galls before the trees leaf out in the spring A few insects and diseases to look for in the next few weeks... Eastern tent caterpillar. Look for the egg masses to see if there is first instar larvae present. First hatch coincides with the blooming of forsythia. For control, remove and destroy the tents. Bacillus thuringiensis (Bt) can be used on young caterpillars. Other options include Confirm (tebufenozide), Conserve (spinosad) and Acelepryn (chlorantraniliprole). Hemlock woolly adelgid. Look for the development of the white, woolly egg masses. Then, monitor regularly for crawler emergence in April. Here, at the research center in Ellicott City this week, a few white, fluffy egg masses are visible. Control: Look for the presence of lady bird beetle adults and larvae as well as other predators that can help control adelgids. Tristar (acetamiprid) can be applied as a foliar spray. Merit (imidacloprid) can be applied as a soil drench or soil injection. It takes 60 days for imidacloprid to become toxic in the plant before controlling the pest. Do not apply imidacloprid during drought conditions unless the area is thoroughly irrigated after an application. Applications can be made in the fall or early spring. Safari (dinotefuran) can be applied as a soil drench. It takes about 2-3 weeks for uptake of dinotefuran. A 2% Hemlock wooly adelgid egg mass horticultural oil or insecticidal soap application can be made to small trees (under 20 ) when crawlers are active later in the season. Thorough coverage is important. Spruce spider mite. These mites are a cool season mites so look for activity this spring. Common plant hosts damaged by spruce spider mites are junipers, spruce, arborvitae, cryptomeria, dawn redwood, hemlock and pine. Control measures include orticultural oil, Hexygon (hexythiazox), TetraSan (etoxazole), Avid (abamectin), Floramite (bifenazate) and Akari (fenpyroximate). Anthracnose on Dogwood (and other woody plants). Anthracnose diseases show up on trees later in the season when it is too late to treat. If anthracnose has been a problem on dogwoods or other trees at sites you monitor, then budbreak is the time to treat to reduce the incidence of disease later in the summer. Control options include Myclobutanil, Banner (propiconazole) and Cleary s 3336 (thiophanate-methyl). Be sure to read the labels for appropriate spray intervals. 5

6 Emerald Ash Borer We (Stanton Gill et. al.) are conducting a training on March 21, 2012 that will help you decide what to do about ash in your customers landscapes. A summary of the article Economic Analysis of Emerald Ash Borer (Coleoptera: Buprestidae) Management Options that was just published in the Journal of Economic Entomology is posted at and might be worth looking at when deciding whether to do nothing or take preemptive action. Journal Article Authors: A.R Vannatta, R.H. Hauer, and N.M. Schuettpelz (University of Wisconsin) Weed of the Week, Chuck Schuster Welcome back to the world of non-desired plant identification and potential control. The winter being as mild as it has been has not slowed many of our weeds down. Wild parsnip, Pastinaca sativa, is a biennial or in some occasions a perennial related to carrot and hogweed. The young plant will form a rosette the first year of growth. As with the carrot, a large erect, tall stem produces several clusters of yellow flowers. This stem grows two to five feet in height and is hollow and branched. The stem will be somewhat hairy. Leaves on the stem are alternate, smaller than the rosette or basal leaves, compound, contain five to ten leaflets and are attached by way of a long petiole that encircles the stem at a node. One noticeable feature of the petiole is that it will have two ridges on the upper surface and three or more ridges on the lower surface. The flowers are small and yellow with five petals, and will be found in clusters that are four or more inches in diameter. Wild parsnip forms a thick white to yellow taproot which will regrow a new plant if cut. Wild parsnip leaves, stems, and flowers have a chemical that will cause intense local burning of the skin upon contact. Contact with the sap can cause increased skin sensitivity to sunlight which can produce false sunburn that can last for several months. If contact dermatitis occurs it is recommended that the person see a doctor. Wild parsnip in bloom Photo: Virginia Tech Weed ID Guide Control of wild parsnip is difficult. Late winter or early spring applications of glyphosate or triclopyr have been successful. Cutting with a shovel several inches below the ground surface can limit growth and flower stalk formation. It will resprout, but this action will reduce the potential for seed production. Spring Is It Here For Good? Can Crabgrass Be Far Behind? Jeffrey Derr, Professor of Weed Science, Virginia Tech Here at the research station (Hampton Roads, VA) we have pear and certain other trees in bloom, as well as forsythia in flower. Flowering of these species has been used by some to indicate the time to apply preemergence herbicides for crabgrass control in lawns and other areas. We have seen pretty dramatic fluctuations in temperatures with highs reaching between 70 and 80 F on March 1, 7, and 8, but lows between 32 and 36 F on March 5, 6, and 7. We generally say that crabgrass starts to germinate when soil temperatures are above 50 F for three or more days. Crabgrass cannot tolerate frost, limiting successful germination this time of year. We cannot predict the future, but it appears that crabgrass could be germinating very soon. Our weather forecast in Hampton Roads for the coming Monday through Saturday (March 12-17) is for highs from 61 to 73 F with lows ranging from 51 to 56 F. This should be conducive to the onset of crabgrass germination. Temperatures may be lower in Maryland so check your long range forecast. It is better to be a little early than a little late with your preemergence herbicide application for crabgrass control. 6

7 The next few days would be a good time to apply a crabgrass preventer. Ideally we would like to have irrigation or rain soon after a preemergence herbicide application. Our 10-day forecast is calling for rain Tuesday, Friday, and Saturday (March 13, 16, and 17) so consider an application on or prior to this Monday to take advantage of Mother Nature doing the herbicide activation for you. We have a number of effective preemergence herbicides for crabgrass control. They will differ in cost and their length of crabgrass control. A single application of a crabgrass preventer generally does not provide full season crabgrass control, especially in a wet summer or when using a shorter-residual product. Consider a split application (early March and early May for example) to extend the length of crabgrass control. Plant Phenology Various trees, bulbs and weeds have been in bloom for the last 2-6 weeks. Plants in bloom include red maples, cherries, persian speedwell, bittercress, snowdrops, daffodils, and others. PLANT PLANT STAGE (Bud with color, First bloom, LOCATION Full bloom, First leaf) Daphne odorata aureomarginata Full bloom (March 8) Columbia Lamium purpureum (purple deadnettle) First bloom (March 1) Ellicott City Spirea x vanhouttei First leaf (March 9) Ellicott City Degree Days (As of March 8) Baltimore, MD (BWI) 39 Dulles Airport 35 Frostburg, MD 1 Martinsburg, WV 17 National Arboretum 54 Reagan National 59 Salisbury Degree day data is posted at Who can you contact for help with plant problems? Diseases: Karen Rane: rane@umd.edu, Go to for information on how and where to submit suspected disease samples to her lab. Insects: Stanton Gill: sgill@umd.edu, (cell) or (office) Paula Shrewsbury: pshrewsb@umd.edu, Brian Clark: bpclark@umd.edu, (Brian covers Prince George s County) Weeds: Chuck Schuster: cfs@umd.edu, Soil Substrates Plant Fertility: Andrew Ristvey: aristvey@umd.edu, Horticulture: Ginny Rosenkranz: rosnkrnz@umd.edu, ext 106 (Wicomico, Worcester and Somerset counties) 7

8 NURSERY and GREENHOUSE Grower Nutrient Management Plan Certification Training Wednesday, April 11, 2012, 9am - 3pm. Attend this session if you need to become certified to write and update your own Nutrient Management plan. Location: Wye Research and Education Center, 124 Wye Narrows Drive, Queenstown, MD For registration information, please contact Debby Dant X115, ddant@umd.edu. For program information, contact Andrew Ristvey, aristvey@umd.edu or John Lea-Cox, jlc@umd.edu. NOTE: There is no cost for this program, but you need to confirm attendance since Extension will provide lunch. Upcoming Programs Invasive Species Program March 21, 2012 Location: Carroll Community College, Westminster, MD Contact: Suzanne Klick, ipmnet.umd.edu 2012 Interstate Ornamental Plant Mngt Conference April 4, 2012 Location: Maritime Institute, Linthicum Heights, MD Contact: Avis Koeiman, ASCFG Mid-Atlantic Regional Meeting June 18, 2012 Roost Flowers and Design Location: Virginia Beach, Virginia ascfg.org 2012 Perennial Plant Symposium July 4-10, 2012 Location: Boston, Massachusetts perennialplant.org OFA Short Course July 14-17, 2012 Location: Columbus, Ohio ofa.org OFA Perennial Production Conference September 10-12, 2012 Location: Grand Rapids, Michigan ofa.org CONTRIBUTORS: Stanton Gill Extension Specialist sgill@umd.edu Paula Shrewsbury Extension Specialist pshrewsb@umd.edu Karen Rane Plant Pathologist rane@umd.edu Chuck Schuster Extension Educator cfs@umd.edu Ginny Rosenkranz Extension Educator rosenkrnz@umd.edu David Clement Plant Pathologist hgic.umd.edu Andrew Ristvey Extension Specialist aristvey@umd.edu Brian Clark Extension Educator bpclark@umd.edu Thank you to the Maryland Arborist Association, the Landscape Contractors Association of MD, D.C. and VA, the Maryland Nursery and Landscape Association and FALCAN for your financial support in making these weekly reports possible. Photos are by Suzanne Klick or Stanton Gill unless stated otherwise. The information given herein is supplied with the understanding that no discrimination is intended and no endorsement by University of Maryland Extension is implied. University of Maryland Extension programs are open to all citizens without regard to race, color, gender, disability, religion, age, sexual orientation, marital or parental status, or national origin.