TPM/IPM Weekly Report

Transcription

1 TPM/IPM Weekly Report for Arborists, Landscape Managers & Nursery Managers Commercial Horticulture March 21, 2014 In This Issue... - Winter of 2014 and related plant damage - Other damage to plants - Problem with winterberry - Dormant oil applications - Eastern tent caterpillars - MDA press release on lawn fertilizer law Beneficial of the Week Degree Days Announcements 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) 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) 2014 Cold and Snowy Winter - Let s Forget about it! By: Stanton Gill IPMnet Integrated Pest Management for Commercial Horticulture extension.umd.edu/ipm Check here for conferences, archived reports, articles, and fact sheets 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 Spring is here and most of us just want to forget about this winter. The most frequent comment has been What a long winter! We just have not had any really nice warm breaks between the cold and snow. We should have known it would be a bad winter when on February 2nd Punxsutawney Phil was awakened at 7:28 a.m., looked around, and returned to his den to predict six more weeks of winter. How Will the Winter Impact Plants this Spring? Some of the leaf scorch damage on evergreens will be very noticeable early in the spring. Some of the other damage is not going to show up until we are well into the spring weather. So, why will there be so much damage from this winter? Late November and December were cold, but the really bad weather waited until January to arrive. On January 4, 2014, temperatures dipped to single digits White pine damage after a snow storm Photo: Mark Schlossberg, Pro Lawn Plus, Inc.

2 followed by a temperature dip to - 4 F on January 7 in Central Maryland. It reached a low of -5 F in Frederick on this date. An artic depression (part of an Artic Vortex shift) sent a cold wave across the Mid-west to the South down to Florida. This winter was the coldest in two decades. On January 22, temperatures dipped to 5 F in Central Maryland followed by a low of - 4 F on January 23. On January 24 it reached 7 F with single digit temperatures for three days in a row. Tree Trunk Cracking and Scorching Several nursery owners have reported cracking on the south sides of smooth barked trees such as redbuds, maples, single stem magnolia, styrax, London plane, and crape myrtle. Besides the cracking of trunks we are getting reports of skip laurel and variegated boxwood that are very scorched. Chinese holly and Koehneana holly are showing severe leaf scorch from the winter cold. Nandina has been planted heavily in landscapes lately and they are showing a lot of winter scorching. Crape myrtles in landscapes, which have fared well for the last 15 years, will likely have branches die back and not have full leaf out. The root system is fairly hardy so the plants should come back from the root system, but this will be a slow process. The ice stormed that occurred on February 5 caused a lot of broken branches on trees such as birch and cherry which means a lot of pruning will be needed in late March. The snowstorm on February 13 dumped an additional 15 inches of snow and ice onto trees, breaking off branches on white pines. Many hedges made up of Leyland cypress, which have rather small root systems for a plant that grows fairly large, were flattened during the February 5 and February 13 winter storms. The total snowfall was 30.7 at BWI airport with the normal to date is The snow continued into early March with 4-7 falling on March 3, followed by three nights of temperatures in the single digits like what we had in January. Of couse, we still had even more snow later in March. Salt and Plants With the Winter Vortex causing one of the longest cold and snowy periods in decades, record amounts of salt were applied to sidewalks and roadways during a 10 week period starting in mid-november and going until the end of January. In Maryland over 280,000 tons of salt were applied to state highways. Virginia put down 112,000 tons and Washington D.C. applied 24,000 tons during this 10 week period. In Maryland as of March 13, approximately 480,000 tons of salt have been applied. We received many photos from landscapers of tree and shrubs covered in white dustings of salt. The benefit for the safety of people on the roads is tremendous with salt applications being credited with reducing winter storm crashes by 85 to 88%. This elevated salt level will damage root systems of plants Heavy salt on trees along raod and we will see damage showing up throughout the spring. Photo: Mark Schlossberg, Pro Lawn Plus, Inc. What Can You Do About the Salt? Applying gypsum to the soil around trees will help move sodium through the soil. You should run a soluble salt test on the soil. If the salt level is above 2 millimohs, then apply gypsum. The rates vary from lbs applied per 100 sq. ft. of root zone area. Heavy Deer Damage In several urban areas the deer damage to landscapes is very heavy this winter. The taxus yews in the landscape must have looked very tasty to cold and hungry deer. In rural areas, especially areas with poor acorn drop this 2

3 year, we are seeing a lot of desperate deer feeding on plant material on which they normally do not feed. Well, this means that people will be replacing a lot of plant material this year which is great news for nursery owners and garden centers. Deer damage on Norway spruce Photo: Craig Greco, Yardbirds, Inc. What Else is Damaging Plants this Winter? Woodpecker Damage to Viburnum Connie Bowers, Garden Makeover Company, sent this photo in January showing a woodpecker causing injury to a viburnum. Last year, we published photos of injury and we had people write in saying it was damage from European hornet. Others were sure it was woodpecker damage. This photo looks like it is settled it is woodpecker damage. Not much you can do for this injury but at least you know what caused it. Sapsucker (left) and damage (right) Photos: Connie Bowers, Garden Makeover Company Lights Girdling Crape Myrtle Brian Scheck, Maxalea, Inc., sent in this photo of a crape myrtle that was being girdled by miniature lights. Brian noted that he is starting to see more of this problem in the field now that people who have outdoor spaces are using lights more during the year. He points out that if you use lights this way that they should be checked for how tight they are on plants on a yearly basis Lights girdling crape myrtle Photo: Brian Scheck, Maxalea, Inc. 3

4 Problem With Ilex verticillata If you grow winterberry (Ilex verticillata) for cut stems, and noticed a berry rot problem last fall, we want to hear from you! Several growers from states in the Northeast and Midwest saw berry discoloration and fruit drop which had a significant impact on the ornamental value of this holiday product. Several fungi, including a Colletotrichum species, have been associated with this rot problem. If you grow winterberry for cut stems and saw symptoms like those in this photo, please drop us a line (rane@umd.edu or sgill@umd.edu) and let us know the extent of the problem, the age of the planting and also which cultivars were affected. If you grow this crop but did not have any problems, we want to know that, too. This information will help us in investigating management tactics to minimize berry rot issues on this cut stem crop. Winterberry fruit rot Photo: Nancy Taylor, Ohio State University Dormant Oil Applications Several nursery and landscape managers have inquired about dormant oil applications. These dormant oil applications (except neem oil) kill insects by suffocating them. Oils also kill insect eggs by penetrating the shells and interfering with metabolic and respiratory processes. Actively growing insects or mites are more susceptible to oil applications than dormant ones. The best time to apply dormant-season oils is after insect dormancy ends in late winter or early spring when insects resume activity. So far, we have accumulated 11 degree days at BWI (50 F base temperature starting January 1). Most insects have not really come out of dormancy quite yet. It will be warm this weekend, but it is just for a day or two, and then the temperatures are predicted to drop to around 40 F for the next week. Everyone is getting edgy about this long winter and wants to make dormant rate oil applications, but with the low temperatures, I would wait and see if the temperatures finally get above 50 F for a couple of days in a row. Eastern Tent Caterpillar Eggs Craig Greco, Yardbirds, Inc., found Eastern tent caterpillar eggs on cherry in late January. David Clement, HGIC, found eggs in Washington, D.C. this week. Keep an eye out for egg hatch which coincides with blooming of forsythia. Eastern tent caterpillar egg mass Photo: David Clement, HGIC 4

5 Press Release from Maryland Department of Agriculture Regarding Lawn Fertilizer Law ANNAPOLIS, MD (February 12, 2014) The Maryland Department of Agriculture (MDA) has announced that since July 2013, 747 turfgrass professionals have been certified to apply fertilizer to properties that they manage, as required by Maryland s newly enacted Lawn Fertilizer Law. The law applies to professionals for hire as well as individuals responsible for turf management at golf courses, public parks, airports, athletic fields, businesses, cemeteries and other non-agricultural properties. In addition, MDA has issued 118 licenses to individuals and businesses engaged in commercially fertilizing turfgrass and lawns. A list of certified professionals is available on the MDA website at We are pleased with the overwhelming response and enthusiasm we have received from the turfgrass industry, said Maryland Agriculture Secretary Buddy Hance. We expect the program to be running at full steam during the next several months and providing water quality benefits to local streams and the Chesapeake Bay. Maryland s lawn fertilizer law went into effect October 1, The law helps protect the Chesapeake Bay from excess nutrients entering its waters from a wide range of non-agricultural sources including hundreds of thousands of urban and suburban lawns. In addition to the new certification requirement for turfgrass professionals, manufacturers of lawn fertilizer products sold in Maryland were required to reduce the nitrogen content and eliminate phosphorus from most lawn fertilizer products. Turfgrass professionals and homeowners alike are now required to obey fertilizer application restrictions, use best management practices when applying fertilizer, observe fertilizer blackout dates and follow University of Maryland recommendations when fertilizing lawns. A winter fertilizer ban is currently in effect until March 1. Turfgrass professionals seeking certification should visit MDA s website at for testing sessions, training materials, license applications and other useful tools. Here are the steps that turfgrass professionals need to take to comply with the law: Register for Training and Certification Professionals hired to apply fertilizer to turf must be certified by MDA or work under the direct supervision of an individual who is certified. MDA offers fertilizer applicator training sessions and certification exams throughout the year. Turfgrass professionals should visit the website for an exam schedule and to download the training manual and study guide. Renew Certificates by June 30, 2015 Professional Fertilizer Applicator Certificates are valid through June 30, Beginning July 1, 2015, certificates will need to be renewed yearly for a $100 fee and verification of two hours of annual recertification training. The MDA website will have information on recertification classes later in the year. Apply for a Business License Licenses are required for individuals or businesses hired to fertilize turf. Businesses are required to employ at least one certified professional fertilizer applicator. The initial license will be valid through June 30, Beginning July 1, 2015, licenses will be valid for one year. Beginning in 2015, license holders will be required to file an annual activity report with MDA covering the previous year. The first activity report is due to MDA March 1, Reporting forms will be available on the MDA website later this year. Applications for a business license may be downloaded from the MDA website. Avoid Penalties Violators are subject to civil penalties of up to $1,000 for the first violation and $2,000 for each subsequent violation. 5

6 Beneficial of the Week: How Important Are Natural Enemies? By: Paula Shrewsbury As we enter the 2014 season I would like to discuss the importance and role of natural enemies in ecosystem function and pest management. First, let s start with insects in general. There are about 1 million described species of insects with an estimated 4 6 million or more still to be described. In addition, insect abundance is estimated to be around 10 quintillion. Insects perform diverse roles in our ecosystems. Many are herbivores that rely on plants as their food resource. However, less than 1% of known insects are estimated to be serious pests of plants. Ecologists have long asked if there are so many insects in the world why is the world still green (i.e. why don t all the herbivorous insects eat all the plants). There are two major forces that prevent this. First, plants have chemical and morphological (thorns, thick leaves, etc.) defenses that prevent insects from consuming them. Second, many insects are natural enemies that consume herbivores, suppressing their abundance and impact on plants. Natural enemies provide a biological control service and play a major role in shaping animal and plant communities in natural and managed environments. In addition to eating other insects they are also eaten by other animals so they are critical links in food webs. Many natural enemies are omnivores and eat insects and plant resources such as seeds, nectar and pollen. Omnivores consume weed seeds suppressing weed growth, and nectar and pollen resulting in pollination of plants. Be sure to respect natural enemies and the important roles they play in maintaining healthy ecosystems and preventing pest outbreaks and damage. When making plant and pest management decisions try to reduce detrimental impacts on these beneficial insects. Scoliid or digger wasp pollinating flowers as it feeds on nectar and pollen. They are also parasitoids of green June beetle grubs. Photo: P. Shrewsbury, UMD Degree Days (As of March 20) Lady beetle and flower fly (very small in center of flower - see arrow) larvae feed on aphids while ants enjoy the honeydew of aphids. Photo: P. Shrewsbury, UMD Baltimore, MD (BWI) 11 Dulles Airport 6 Frostburg, MD 2 Martinsburg, WV 17 National Arboretum 28 Reagan National 28 Salisbury 41 To check degree day (DD) accumulations in your local area go to: Note: degree days reported in this newsletter for various pests use the Weather.com web site, a base temperature of 50 F, a start date of January 1st, and the date of monitoring as the end date. 6

7 Upcoming Conferences 2014 Interstate Ornamental Plant Management Conference April 7, 2014 Location: Maritime Institute, Linthicum Heights, MD Contact: Avis Koeiman, Maryland Arborist Assocation Pest Walk May 28, 2014 (afternoon to early evening) Location: Stevenson University Stormwater Management Program August 20 and 21, 2014 TWO Locations: August 20 - Montgomery County Extension Office, Derwood, MD August 21 - Robinson Nature Center, Columbia, MD Procrastinators Pesticide Applicators Program June 6, 2014 Location: Montgomery County Extension Office, Derwood, MD Procrastinators Pesticide Applicators Program - Eastern Shore June 13, 2014 Location: Wye Research and Education Center, Queenstown, MD MGGA Field Day June 19, 2014 (afternoon through early evening) Location: Tidal Creek Growers, Davidsonville, MD Greenhouse Biocontrol Conference August 6, 2014 Location: Maritime Institute, Linthicum, MD 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 David Clement Plant Pathologist hgic.umd.edu Andrew Ristvey Extension Specialist aristvey@umd.edu Ginny Rosenkranz Extension Educator rosnkrnz@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, Professional Grounds Management Society, 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.