Landscape Alerts – Page 5 – Center for Urban Agriculture

Gloomy Scale Crawlers are Active and Vulnerable

November 30, 2015May 28, 2015 by Willie Chance

Info taken from the EcoIPM website and the SE Ornamental Horticulture & IPM website

Gloomy scale

Gloomy scale, Melanaspis tenebricosa, is an armored scale that feeds on maples and other tree species. It becomes very abundant on red maples on streets and in landscapes and can cause branch dieback and tree death in some cases. It is not unusual to find trees with nearly 100% of their trunk covered in scale. Street trees are particularly prone to gloomy scale. Crawlers of this scale are active now and can be seen on bark and under scale covers. One of the reasons we have found this to be such a pest is that female gloomy scales produce about 3 times as many eggs when they live on relatively warm trees (like in a parking lot) than when they live on cooler trees (like in a shady yard). This amazing work is outlined in a recent paper by Adam Dale.

Control of this scale is complicated because crawlers emerge over 6-8 weeks so it is impossible to treat all the crawlers at once with horticultural oil or other contact insecticide. This is different than in other scales, such as euonymus scale, in which all crawlers are produced within a narrow window of 2 weeks or so. Adam Dale took a video of some gloomy scale crawlers so you can get an idea of how tiny and nondescript they are. This may also give you an idea of why scales are so vulnerable at this stage to the environment, predators, and insecticides like horticultural oil. Once they produce their thick waxy cover they are much less vulnerable to all these factors.

See video of gloomy scale crawlers (immatures).

Read the original article.

UGA mobile app helps control roadside weeds

November 30, 2015May 22, 2015 by Willie Chance

Patrick McCullough, a weed scientist with the UGA College of Agricultural and Environmental Sciences, decided to create the Georgia Roadside Management app after Georgia DOT officials approached him for help.

“The biggest problem they have is fighting invasive weed species, like broomsedge, vaseygrass and Johnsongrass. They are major species, and they are spreading, increasing maintenance costs and, more importantly, reducing safety for motorists,” said McCullough, a UGA researcher based on the campus in Griffin, Georgia.

Ray Dorsey, Georgia DOT agronomist manager, says tall weeds, like Johnsongrass, and invasive weeds, like kudzu, create “sight and distance problems,” especially at driveways and intersections.

“When we do road building, the contractors are required to replace the grass. Our permanent grasses of choice are bahiagrass and bermudagrass because they can help choke out weeds,” he said.

Using a partial research grant from Georgia DOT, McCullough designed the app using DOT terminology to make the tool user-friendly for workers. “All the information they need to make the best management decisions for controlling roadside weeds and vegetation is now literally at their fingertips,” he said.

The app debuted last fall, and Georgia DOT agronomists have now used it for six months.

“Everyone who’s downloaded it thinks it’s great,” Dorsey said. “We are one of the first DOTs to have an app for vegetative management,” he said.

Like all recommendations involving pesticides, the guidelines are frequently changed and updated. “Before, we had to make revisions, make paper copies and update all the training notebooks,” he said. “Now, we just ask Patrick to update the app.”

Unlike the paper notebooks, the app includes images of plant material. “It was too expensive to print color photos in the manual before. Now, we can look at a picture of the weeds and match them with what we see. (This app) is really a great tool,” he said.

The app covers much more than how to control vegetation. It also includes information on growth regulators, first aid, personal protection, equipment maintenance and mowing procedures.

Created for use on iPhones, the app can be downloaded for free on iTunes. “It’s specific to Georgia DOT and uses their codes, but DOTs in other states would benefit from it, too,” McCullough said.

Download the app for free on iTunes.

Video on horticulture’s essential role in pollinator stewardship

November 30, 2015May 21, 2015 by Willie Chance

Info courtesy of the UGA Nursery Production Facebook page by Matthew Chappell, UGA Original article published in Greenhouse Grower magazine.

A newly released educational video provides valuable information on horticulture’s essential role in bee and pollinator stewardship.

“Protecting Bees & Pollinators: What Horticulture Needs to Know,” narrates the current state of bee and pollinator health, provides information on factors that impact pollinators and the environment, including the use of pesticides, and underscores the beneficial role horticulture plays in providing healthy pollinator ecosystems.

The seven-minute video was produced as part of the horticulture industry’s Bee & Pollinator Stewardship Initiative, a collaboration by the Horticultural Research Institute, AmericanHort, Society of American Florists (SAF) and the American Floral Endowment.

Oak leaf blister: What is this problem on oak leaves?

November 30, 2015May 20, 2015 by Willie Chance

Oak leaf blister

Compiled by: Dr. Jean L. Williams-Woodward, UGA Extension Plant Pathology

Disease Symptoms:
Bulging, blister-like spots on leaves, may cause leaf distortion. Underside of leaf turns brown following spore production. Can be confused with eriophyid mite or midge damage. Affected leaves drop prematurely.

Disease Management:
Disease seldom causes significant damage. Apply fungicide spray when leaf buds swell in the spring and reapply at 7-10 day intervals until the leaf fully expands to reduce disease.

Bagworms: What are these things hanging in my trees?

November 30, 2015May 15, 2015 by Willie Chance

Bagworms

Info taken from the publication Control of Common Pests of Landscape Plants by Tim Daly, Gwinnett County Cooperative Extension Agent and Beverly Sparks & Will Hudson, Extension Entomologists.

Bagworms construct and live inside a 1- to 2-inch long tough, tear-shaped portable silken case. These bags are the insect’s most easily seen and identifiable feature. Outside, the silken texture of the bag is somewhat concealed with layers of leaf, twig and bark fragments. The bag has an opening at the larger end that allows the worm to partially crawl out to make repairs to its bag and eat.

Bagworms attack broadleaf and coniferous trees and shrubs. Here are some control measures.

Follow proper watering, fertilizing and pruning practices.
Remove other stress factors from trees when possible.
Infested plant material cannot be treated and should be removed and disposed of.
Protect trees from infestation or reinfestation by using products containing bifenthrin or permethrin. Make first application in April and subsequent applications in late May, mid-July and late August.

To find more ID and control information on this or other landscape insects read the UGA publication Control of Common Pests of Landscape Plants

To find pesticide recommendations and use information visit the Georgia Pest Management Handbook.

May has been warmer and drier

November 30, 2015May 14, 2015 by Willie Chance

May 2015 is half over and it is time to see how the monthly climate is doing so far. The maps from the High Plains Regional Climate Center below show that for the region as a whole, temperatures are running about 1.5 degrees above the 1981-2010 normal, while the precipitation is much below normal and in some areas none has fallen at all, which is shown on the “percent of normal precipitation” map as an area of dark red, indicating zero percent of normal rainfall for the month. Atlanta broke their record for the driest start to May before finally getting rain on 5/17. Athens, GA is the driest May to date on record and Macon is tied for the driest, although rain is likely at both locations this week.

For the rest of the month, warmer than normal temperatures are expected to continue. Rainfall is expected to increase and may even be above normal for the rest of the month, although it will be spotty.

Lawn burweed: What is this weed with sharp spurs in lawns?

November 30, 2015May 5, 2015 by Willie Chance

Lawn Burweed – It’s a Stick Problem

Tim R. Murphy – Retired Extension Weed Scientist, The University of Georgia
Edited from a longer article you can find here.

The weed in question is most commonly lawn burweed (Soliva pterosperma), a.k.a. spurweed, stickerweed, sandbur, sanbur and sandspur. Lawn burweed is a winter annual member of the Aster family. The weed germinates in the early fall months as temperatures cool and remains small or inconspicuous during the cold winter months. However, as temperatures warm in the early spring, or about the same time as spring sports activities, lawn burweed initiates a period of rapid growth and begins to form spine-tipped burs in the leaf axils. The sharp-tipped spiny burs of this weed can irritate the skin.

Key identification characteristics of lawn burweed are:

opposite, sparsely hairy leaves that are divided into numerous segments, or lobes
small, inconspicuous flowers, and c) spine tipped burs that are found in the leaf axils (junction of leaf and stem).
attains an overall diameter of up to 6 inches and a height of about 3 to 4 inches.
It is commonly found in the Coastal Plain and Piedmont regions of Georgia.

Lawn burweed: What is this weed with sharp spurs in lawns? — The seeds with their sharp spines grow in the leaf axils (where the leaf and stem come together)

Lawn burweed is easily controlled during the winter months.

December, January and February are ideal months to apply herbicides to control this weed. Lawn burweed is small and easier to control at this time of the year than in April and May. Also, turfgrasses are not actively-growing during the winter months and have better tolerance to some herbicides.

See the UGA Pest Management Handbook for pesticide recommendations for your turf type. Two to three weeks after the initial application, lawn burweed control should be evaluated. If control is not acceptable, an additional application may be necessary.

Lawn burweed can be controlled in late-March, April and early May, however, two main facts should be considered.

Lawn burweed begins to die as late spring temperatures approach 90° F and the plant is harder to control once the spiny burs or stickers have formed. Multiple herbicide applications are usually necessary, which increases the risk of temporary injury to the turfgrass.
Additionally, it takes time for the herbicide to control lawn burweed, and after death, it takes time for the dead lawn burweed plants to decompose. Therein lies one of the main problems with late treatments. Dead lawn burweed plants contain dead, or brown spine-tipped burs. Dead or alive, the spiny burs still present a problem. The only recourse at this point is to allow time for the plant to naturally decompose.

For more information:

Find pesticide recommendations – UGA Pest Management Handbook

Identify lawn weeds

Find your local UGA Extension Office

Facelis or trampweed – Cottony weed invades lawns

November 30, 2015May 4, 2015 by Willie Chance

“Cottony Weed” in Lawns

Tim R. Murphy, Retired Extension Weed Scientist
PDF Version of Cottony Weed article

It seems that all of a sudden, numerous lawns in Georgia are turning white. Well it is not snow, nor is it left over cotton from last fall. The “cottony” appearance is due to the presence of a weed named facelis (Facelis retusa).

Facelis

Facelis, also called annual trampweed, is a winter annual member of the Aster family that reproduces by wind-blown seed. This weed reaches heights of 4 to 6 inches and has alternate wedge-shaped leaves with a small tooth at the tip. The upper leaf surface is green, while the lower leaf surface is densely gray due to the presence of leaf hairs. Flowers are very inconspicuous; however, seed have soft, white bristle-like hair. With severe infestations the lawn becomes white when seed are being released from the plant. Typically facelis is found in lawns with a low density of turfgrasses, as well as on open, droughty, low fertility sandy or clayey soils.

Facelis actually germinates in the fall and late winter months, produces seed in late April to June and then dies. May is not the preferred time to control facelis, as the weed is essentially in the process of dying.

There has been very little research done on controlling this weed in turfgrasses. Additionally, this weed does not appear on herbicide labels. However, herbicides that contain 2,4-D, MCPP, dicamba and triclopyr or atrazine applied during the mid-winter through early spring months should control facelis.

Since this weed is found on droughty, low-fertility sites, try to improve the turfgrass density through liming, fertilization and irrigation.

For pesticide recommendations see the UGA Pest Management Handbook.

Alfredo Martinez and Clint Waltz receive Walter Barnard Hill awards

November 30, 2015May 3, 2015 by Willie Chance

Alfredo Martinez and Clint Waltz receive Walter Barnard Hill awards — Alfredo Martinez, a professor of plant pathology in the College of Agricultural and Environmental Sciences, focuses on disease management and production practices for turfgrass, small grains and grass forages in Georgia. Image credit: Sharon Dowdy.

The University of Georgia’s Office of Vice President for Public Service and Outreach honored UGA Extension specialists for their outstanding service to the state.

Alfredo Martinez and Clint Waltz received Walter Barnard Hill Awards for Distinguished Achievement in Public Service and Outreach in recognition of their outstanding contributions to the improvement of the quality of life in Georgia and beyond.

Martinez, a professor of plant pathology in the College of Agricultural and Environmental Sciences, focuses on disease management and production practices for turfgrass, small grains and grass forages in Georgia.

Waltz, professor and turfgrass Extension specialist in the College of Agricultural and Environmental Sciences, has statewide responsibilities in all turfgrass management areas, including turfgrass water management.

For more information visit the Office of the Vice President for Public Service and Outreach.

Leaf galls – What is this strange fleshy growth on azalea leaves?

November 30, 2015May 2, 2015 by Willie Chance

Leaf galls

Azalea leaf gall, caused by the fungus Exobasidium vaccinii, are common on azalea in the spring during wet, humid, cooler weather.

The fungus invades expanding leaf and flower buds causing these tissues to swell and become fleshy, bladder-like galls. Initially, the galls are pale green to pinkish. Eventually, they become covered with a whitish mold-like growth. Fungal spores are produced within the white growth and are spread by water-splashing or wind to other expanding leaf or flower buds, or they adhere to newly formed buds, over-winter, and infect these buds the following spring. Older leaves and flowers are immune to infection. As the galls age, they turn brown and hard.

The disease does not cause significant damage to affected plants. It just looks unsightly.

Azalea leaf gall can be prevented in subsequent years by removing the galls by hand as soon as they are detected and destroying them before they turn white and release spores. Fungicides are generally not needed or recommended for control of this disease.

For more information on azaleas, see the UGA publication Selecting and Growing Azaleas.

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