§ Time to spring into 2007
Landscape and nursery
§ New products for the landscape and nursery
§ Thielaviopsis (black root rot)
§ Scouting for weeds: Hairy bittercress
§ Scouting for insects: Aphids
§ Scouting for diseases: Botrytis blight
Turfgrass
§ New products for turfgrass
§ Thinking turf in the early spring
Around the home
§ Early season bug news
Other news
§ Enviro-weather is geared-up for the 2007 growing season
We seem to be having a normal spring for
If you have suggestions related for these newsletters, please feel free to contact us at (517) 353-4951 or catalert@msu.edu
Our next issue of the Landscape
Alert will be published April 13.
– Joy Landis, editor and Rebecca Lamb,
assistant editor.
Quite a few new products became available in the last year for use in the nursery (N) and landscape (L). Here is a quick description of these products and what they can do.
Flagship (N). Thiamethoxam from Syngenta. For grubs, soft scales, beetles, leafhoppers
and aphids. Soil applications in July will work well for grub control. Soil
applications will also provide good systemic control of the other pests on the
label for four to eight weeks after application. This product can also be used
as a foliar spray.
Tristar (L, N). Acetamiprid from Cleary. For use as a foliar spray on outdoor ornamentals and in nurseries. Aphids, leafhoppers, scales and beetles.
Safari (N, L). Dinotefuron from Valent. For aphids, leafhoppers, thrips, adult beetles, beetle borers, scales and thrips. Safari works as a soil systemic or as a foliar spray.
Celero (N, L). Clothanidin from Arysta. For outdoor ornamentals and greenhouses, scales, adult beetles, beetle borers, leafhoppers, aphids and grubs. Celero works as a soil systemic or as a foliar spray. Soil applications in July will provide excellent grub control later that summer and fall.
Distance (N, L). Pyriproxyfen from Valent. A safe IGR for use on armored scales. Recent tests have shown that Distance is one of the best sprays available for control of armored scales such as Eunymous, oystershell and lilac scales.
Ultiflora (N, L). Milbamectin. A new miticide from Gowan. Similar to Avid. This is a restricted use pesticide.
Judo (N). Spiromesifen from OHP. For mites and whiteflies.
Forbid (L). Spiromesifen from Bayer Corp. For mites and whiteflies.
ProMite (L, N). Hexakis from Sepro. A selective
miticide not harmful to predator mites or beneficial insects (an old version of
this product was Vendex). This
is a restricted use pesticide with a 48 hour re-entry interval.
Soil drench or soil injections of Discus, Safari, Flagship or Celero. These products will also work as a fall treatment for most spring and early summer pests such as soft scale insects, honeylocust plant bug, potato leafhopper and meadow spittlebug. These products are not very effective against mites or caterpillars.
Editor’s note: If you also work with greenhouse production, please check out our Greenhouse Alert newsletter on the Internet at: http://ipm.msu.edu/greenhouseAlert.htm. The following article was published in our most recent issue. The Greenhouse Alert posts articles from December through early May and is a web-only publication.
Thielaviopsis has long been known in the greenhouse industry as a root rot pathogen that particularly affects pansies, petunias and vinca. Many perennials are also susceptible to this disease. Over the last year, I have seen an increasing number of perennials and woody ornamentals with Thielaviopsis, including Digitalis, Gaillardia, Geranium sp., Ilex, Leucanthemum, Phlox subulata, Phlox paniculata, Taxus cuspidata and Viola. Greenhouse growers, nurseries and landscapers working with perennials should be aware of this disease and the symptoms that it causes. (view images)
Thielaviopsis basicola is a fungus that infects roots of susceptible plants. Infection of the roots causes both above and below ground symptoms. Infected roots are darkly colored, hence the common name for the disease, black root rot. The dark coloration is created by the reproductive structures of the pathogen, which have a dark outer surface. Above ground symptoms are more readily noticeable and include chlorosis (yellowing), stunting, lack of vigor and plant death. Chlorosis caused by Thielaviopsis is easily mistaken for symptoms of a nutrient deficiency. However, unlike symptoms caused by a nutrient deficiency diseased plants do not respond positively to increased fertility. Infected woody ornamentals also develop chlorosis as well as defoliation after the root systems become significantly infected. Large or well established plants may not show obvious symptoms until the root systems are heavily infected.
Definitive diagnosis of this disease is not possible based exclusively on disease symptoms. Diagnosis requires microscopic evaluation of infected plants to confirm the presence of the reproductive structures (chlamydospores) on root tissue. This type of analysis can be readily done by any plant diagnostic lab.
Thielaviopsis is soil-borne, and the reproductive structures of this pathogen are well adapted to persist for several years in soil and plant debris, even without a live host plant. Soil conditions influence disease development. The disease is more severe in cool soils that have a pH range of 6 to 7. Observations suggest that wet soils are more conducive to disease development than dry soils.
Prevention is the best and most practical control strategy. Take the time to carefully inspect plant material when it is received and again when it is installed in a landscape. Randomly pick a few plants to remove from their containers and closely examine the root system. Diseased plant material should not be installed in the landscape as its condition will only deteriorate and soil at the site will become infested with the long-lived chlamydospores of this pathogen. Effective fungicide treatments options are available, but treatment is most efficient with plants that are still in containers at the greenhouse or nursery. On site, soil drench applications can be done, but these treatments are best when done preventatively rather than curatively.
Thielaviopsis is most often a problem in situations where containers or media is reused. Containers and media from infected plants should not be reused. If containers are reused, they should be carefully sanitized with commercial sanitizing products. Extra care needs to be used to remove all residual media or soil particles before treating the containers with a sanitizing product. Soil or media residue left on the inside surface of the containers prevents direct contact of the sanitizing products with chlamydospores that may be present, thereby decreasing efficiency of the sanitation process.
Diseases of Woody Ornamentals and Trees in Nurseries, 2001.
Edited by R.K. Jones and D. M. Benson. The American Phytopathological Society (
Hairy bittercress (Cardamine hirsuta L.) (view images)
Family. Brassicaceae (Mustard)
Life cycle. Rapidly growing winter or summer annual.
Leaves. Round cotyledons on long petioles are followed by heart- to kidney-shaped first two true leaves. Subsequent leaves are compound with two to eight alternately arranged leaflets and larger terminal leaflet. Leaflet margins are shallowly toothed to lobed. Mostly hairy leaves initially develop from a basal rosette, followed by a few smaller, narrow stem leaves. Basal leaves are persistent through maturity.
Stems. Mostly erect, smooth, angled stems branch mainly at the base. Stems are less than 12 inches tall.
Flowers and fruit. Very small, white flowers with four petals are arranged in terminal clusters. Fruit are very narrow, about 1-inch-long, flattened, upward-pointing capsules that explosively eject numerous small seeds.
Reproduction. Seeds. Multiple generations may be produced in a single year.
Smallflowered bittercress: Cardamine parviflora L.
Differs by having up to six leaflet pairs and basal leaves that are not present at maturity.
Hairy bitttercress is one of the most troublesome weeds in nursery production. It is a prolific seed producer with a short life cycle (three to four weeks) that is capable of ejecting seeds several feet from the main plant with specialized fruit capsules. Cultural options include sanitation, mulching, subirrigation and large-porous media. The best option is the use of preemergence herbicides to control the ungerminated seeds in the soil. These options include granular formulations of OH2, Regal O-O, Rout, Ronstar, Surflan, Showcase, XL and SnapShot.
Aphids use their piercing-sucking mouthparts to withdraw fluids from
terminal growth and leaf undersides. This results in leaf curling or
distortion. Aphids produce honeydew, a clear, sticky liquid. Aphids feeding on
plants outdoors are susceptible to many beneficial insects (natural enemies),
including parasitic wasps, ladybird beetles, green lace-wings and hover flies.
Many species of aphids feed on a wide variety of herbaceous perennials.
Management. A hard water spray will quickly remove aphids from plants and minimally affect any beneficial insects. Avoid overfertilizing and overwatering plants. Remove weeds from adjacent areas – many weeds serve as a reservoir for aphids. Contact and systemic insecticides may be effective in controlling aphids.
Pathogen. Botrytis
cinerea.
Hosts. Very large host range, some of the most susceptible include Delphinium, Hosta, Iris, Lilium, Primula, Rudbeckia and Viola. Blossoms are especially susceptible.
Symptoms. Seedling blight, leaf spots and blight, distortion of young leaves, crown rot and blossom blight.
Signs. In high relative humidity, grayish, fuzzy mold on the surface of the affected tissue is visible with the naked eye.
Spread. Spores are produced in mass under humid conditions and are readily released and moved by air currents. Additionally, overwintering structures (sclerotia) are formed and can persist in soil and plant debris. Sclerotia are found on the surface of heavily diseased plant material.
Management. Sanitation and aeration procedures that reduce humidity levels around plants and appropriate fungicide applications are recommended for disease control. Botrytis cinerea can sporulate on dead plant material; fallen leaves and petals should be carefully removed from production areas. Trash cans used for dead plant tissue should not be kept in production areas. Regular fungicide applications will likely be necessary to reduce losses on especially susceptible hosts grown in humid environments.
One new product that should be available this year is
The active ingredient is thiamethoxam, a nicotinoid
insecticide in the same chemical family as Merit and Arena. Like Merit and
Arena,
As many of us are starting to settle down for a long weekend of bouncing basketballs, it’s likely that the bouncing temperatures over the next weeks will get at least some of us to venture out into the lawn to look around and make plans for grooming our landscape this year.
If you venture out to your lawn and you think you have a crabgrass problem, think again. You do not have crabgrass present in your lawn at this time of year. Two grasses can be commonly confused as crabgrass and they are tall fescue and quackgrass.
Tall fescue usually starts growing quicker in the spring than the traditional Kentucky bluegrass lawn mixture, and thus, gets some folks to think it must be crabgrass. Usually by May the small patches of tall fescue that might be in your bluegrass lawn start to blend back in as the bluegrass starts to grow. If you’re had enough of the tall fescue patches you can dig them out, spray them out with a non-selective herbicide, or use solarization (Secure clear plastic on the patch and leave in place for about a week to “burn out” the fescue.).
Quackgrass can also be confused with crabgrass for those that have crabgrass on the brain. To identify which grass or weed you actually have, please visit www.msuturfweeds.net. For tips on controlling quackgrass refer to the May 5, 2006, Landscape Alert issue.
If you’re feeling the urge to go outside and apply some fertilizer to help that turf get growing, go back inside and lay down until that feeling goes away. It’s only mid-March, and in many areas of the lawn with northern exposure, it’s questionable whether the frost is even out of the ground yet. In most situations, the earliest the first fertilizer application should be applied would be in combination with a preemergence crabgrass herbicide application, which in most years is applied around April 15. If you applied a fall fertilizer application and do not need to apply a preemergence application in mid-April, you could probably easily wait until May to make your first fertilizer application of the year.
If I were to guess I would predict that the first “real” mowing of the year is probably at least three weeks away. You might want to take a shot at starting the mower this weekend in case you need some regular maintenance to get it purring. The lines at the local lawn mower repair shop are going to get long in a hurry. If nothing else, make sure to take your blade to get sharpened.
It’s only March 16 and already the bugs are starting up. During the last week or so the lab has received samples of termite swarmers, winged carpenter ants and stoneflies from homeowners. The termites were collected from a large mass that appeared in someone’s basement (never a good thing). The carpenter ants were seen crawling out a small hole in the ceiling (also not a good thing). Stoneflies are harmless aquatic insects that are among the first insects to become active in the spring. Stoneflies emerge from rivers and streams and occasionally show up in or on nearby homes. See a picture of an adult stonefly at: http://www.aegaweb.com/secc/nat_gal/insectos/plecoptera/plecopt1.jpg.
Ready for its second season, the Enviro-weather website all
set to be your source for agricultural weather and weather-based plant and pest
management decision making tools. Just visit http://www.enviroweather.msu.edu and you will have access to
information and management products from 49 weather stations across
Weather information such as National Weather Service local forecasts and real time radar, overnight temperatures and weather summaries, including temperature, degree days and rainfall can be accessed by clicking on the weather station of interest to you. In addition, you can get summaries and decision making products specific for your favorite crop or area of interest by choosing from links to forestry and Christmas trees, fruit, potato or turfgrass.
All new GDDTracker for 2007
By clicking on turfgrass you can select “GDDTracker” where you will be directed to MSU’s growing degree day tracker developed by MSU Department of Crop and Soil Sciences. There you can get information on timing for herbicide applications to control various weeds in turfgrass, sign up for email alerts, get a growing degree day forecast for the upcoming week and more. Additionally, many turfgrass disease models will soon be available to aid in fungicide application timing. Send comments or questions about Enviro-weather to eweather@msu.edu.
For easy access to Enviro-weather’s home page just type “enviro-weather” in the Google search engine and click “I’m Feeling Lucky.” In most other search engines Enviro-weather will be at the top of the results list. Watch future editions of Landscape Alert for more Enviro-weather tips.
