by Matt Lollar | Sep 29, 2016
Tropical sod webworms (Herpetogramma phaeopteralis) have recently been encountered in a number of yards in the Panhandle. The worms usually feed in large groups and unfortunately, the first, and basically the only, sign of damage is often a large area of shorter grass due to their feeding. The arrival time of sod webworms is also unfortunate because they are part of a group of caterpillars that successively attack turf including fall armyworm (Spodoptera frugiperda), striped grass loopers (Mocisspp.), and the fiery skipper (Hylephila phyleus).
Sod webworm feeding damage in the turf thatch layer. Photo Credit: University of Florida/IFAS Extension.
Description
Larvae
Caterpillars are light yellow to orange with brown spots on each body segment and they have a dark, orange-brown head. They will grow to a full length of slight less than 1/2 inch.
Pupae
The reddish brown pupae are about about 1/4 inch long. The pupae are typically found in the upper thatch layer.
Pupa found in cocoon in St. Augustinegrass thatch. Photo Credit: Steven Arthurs, University of Florida/IFAS
Adults
The moths brown with splotchy wings and are about 3/4 inch wide.
Control
Sod webworms are difficult to control because of their spontaneity. However, in the lawn they hide in the thatch during the heat of the day. Over watering and fertilization can increase the amount of thatch. It is important to follow UF/IFAS guidelines for home lawn management.
The first line of defence is healthy turf. Proper fertilization, irrigation, and mowing height can decrease susceptibility of turfgrass against sod webworm. Over-fertilization is a common cause of caterpillar outbreaks in lawns. Cultural practices such as thatch removal by vertical mowing can help eliminate populations. Eggs are laid on grass blades and removal of grass clippings might also reduce populations.
Numerous chemical control options are available, but softer chemicals such as insecticides containing the bacteria Bacillus thuringiensis are recommended as a first line of defense. Insecticides should be applied in the morning or evening during feeding time. For additional control strategies and basic information please visit the UF/IFAS Sod Webworm Publication.
by Blake Thaxton | Sep 29, 2016
St. Augustinegrass roots rotted due to take-all root rot. (Photo Credit: IFAS Photos)
The crisp air of fall is upon us. Maybe. We live in northwest Florida and we are not experiencing the change in weather just yet. With the change in weather coming, we are having specific issues in turfgrass lawns and are sure to have others in the near future. Extension agents in the western panhandle have come into contact with several St. Augustine lawns with symptoms and signs of take-all root rot (Gaeumannomyces graminis var. graminis) and we can soon expect with cooler temperatures for Large Patch to be rearing its ugly head.
Early aboveground symptoms of take-all root rot. (Photo Credit: IFAS Photos)
Take-all root rot is sometimes referred to as a “stress disease”, as it is brought on by stressful weather conditions and improper management. Periods of rainfall can provide conditions for the disease to affect all warm season grasses. Other stresses such as improper mowing height, improper irrigation, and improper fertilization can worsen the situation. For example, St. Augustinegrass, except dwarf cultivars, should be mowed at 3.5 to 4 inches and the mower should never remove more than 1/3 of the leaf blade at any cutting. With the current high temperatures and prolonged periods of rainfall it can be difficult to follow this practice. When a homeowner does not mow the lawn in a timely manner and lets the lawn grass get much too high and cuts more than 1/3 of the grass blade, this can become a stress to the lawn. Fungicide sprays can be made during favorable environmental conditions, before symptoms are seen to protect from infection with take-all root rot for high valued properties. To learn more about take-all root rot refer to this University of Florida/IFAS Extension publication: Take-all Root Rot
With the fall weather coming, please be sure to read and learn about large patch disease as well. This can brought on by temperatures of less than 80 degrees and high humidity or extended periods of rainfall. Read the University of Florida/IFAS Extension publication for more information: Large Patch
For any other information needed regarding proper lawn management, please visit Your Florida Lawn or contact your local UF/IFAS Extension office.
by Ray Bodrey | Sep 8, 2016
Driving through rural panhandle counties this time of year, one finds pastures with thick green canopies, exploding with yellow-gold flowers. Perennial peanut is in bloom. This is a highly nutritional forage option for livestock and also makes for a beautiful urban groundcover alternative to turfgrass.
Perennial Peanut Field. Photo credit: Ray Bodrey, UF/IFAS.
Perennial peanut was introduced from Brazil in the mid 1930’s. Though a non-native, the perennial peanut has not been shown to be a nuisance nor an invasive. The plant is in the same genus as the peanut that humans consume. However, this plant is a true perennial, living year to year. Perennial peanut does produce a small seed pod. But rhizoma perennial peanut, Arachis glabrata, does not reproduce by seed. Therefore, wildlife, specifically birds, are unable to disburse the plant into unintended areas.
As a side note, few perennial peanut cultivars, such as Arachis pintoi or “pinto peanut”, can be planted by seed. This species has stolons or “runners” and will produce adventitious roots at the nodes. The pinto peanut has become confused in nursery trade with the Florida-developed perennial peanut. Limited research to date has shown how well pinto peanuts perform as groundcover. The pinto peanut is more susceptible to winter kill, insect damage and nematodes than the cultivar Arachis glabrata.
The Florida developed perennial peanut is used mostly for hay or grazing by livestock such as horses, beef & dairy cattle, sheep and goats, as well as wildlife such as deer, rabbits and turkeys. The most common cultivars for pastures are “Florigrazed” and “Arbook”. These cultivars were released by UF IFAS and USDA in 1978 and in 1985. Since the release, these cultivars have also has been used in citrus groves as a cover crop as well as a ground cover in roadway medians. In Florida, it has been planted on approximately 30,000 acres.
Perennial peanut is high in nutritional value and is easily digestible by forage animals. It’s also a nitrogen fixer. Like all legumes, perennial peanut obtains its nitrogen from a bacteria associated with the plant’s root system. Therefore, it naturally adds nitrogen to the soil, reducing the amount of fertilizer needed if used with other crops or plants in a landscape.
Perennial peanut will reach ½ – 1 ½ feet in height. The plant is propagated using rhizomes and can be purchased as mats of sod or in containers. With its extensive root system, rhizoma perennial peanut spreads across the ground as a sod grass would perform. Perennial peanut grows best in sandy to sandy loam soils with a target soil pH of 6.0 although a soil range of 5.8 – 7.0 is adequate. It requires high moisture, with at least 30 inches of rain per year.
In home landscapes, several cultivars are available and have limited maintenance issues. “Ecoturf” and “Arblick” are the most popular cultivars used due to their lower height and profuse flowering. These cultivars thrive in coastal areas as they are considered salt tolerant. Salt spray, drift and short term salt water flooding have little effect. Mowing is not required but edging may be needed as the plant spreads. Weed control is the most concerning, especially during establishment. For pest management, peanut stunt virus cases have been reported. The symptoms are leaf mottling and yield depressions, but are rarely a problem unless the plant is under drought or nutrient stress.
All information considered, perennial peanut is a great option for panhandle livestock producers or the home landscape enthusiast.
Supporting information for this article can be found in the UF/IFAS EDIS publications:
“Guide to Using Rhizomal Perennial Peanut in the Urban Landscape”, by Robert E. Rouse, Elan M. Miavitz and Fritz M. Roka.
“Rhizoma Perennial Peanut”, by M.J. Williams, Y.C. Newman and Ann Blount.
“Perennial Peanut: A Quick Reference”, by Yoana C. Newman, Cheryl L. Mackowiak, Ann R. Blount and Jason Ferrell.
“Plant Materials Fact Sheet: Rhizoma Perennial Peanut (Arachis glabrata) – The Perennial Peanut for Urban Conservation in Florida”, by USDA NRCS.
by Carrie Stevenson | Jul 19, 2016
Florida home and yard. Home, house, stone pavers, walkway, yard, landscaping. UF/IFAS Photo: Tyler Jones
Dr. Ramon Leon, Extension Weed Specialist, West Florida REC, Jay
Last year the International Agency for Research on Cancer (IARC) of the World Health Organization (WHO) classified glyphosate as “probably carcinogenic to humans.” This generated a lot of controversy because the Environmental Protection Agency (EPA), the European Food Safety Authority, and recently a joint report between the Food and Agriculture Organization (FAO) and WHO concluded that glyphosate is unlikely to be carcinogenic in humans.
As a University of Florida/IFAS Weed Specialist, I have been receiving multiple phone calls and e-mails from homeowners, homeowner associations (HOA), lawn care companies and contractors, municipalities, and county managers requesting a list of herbicides that are “safer” than glyphosate. When I ask them the reason for this particular preference, all of them acknowledged that their concern originated from hearing about the IARC report.
The first point that I always explain to people concerned about this issue is that most of the scientific evidence indicates that glyphosate does not have a higher carcinogenic risk compared to many other substances that they are normally exposed to in their daily activities. The second point is that it is important to continuously monitor how chemicals we use affect our health and the environment in the long run. The IARC report is a reminder that we should keep a close eye on glyphosate, the most widely used herbicide in the world, but it is not necessarily a call to stop using it, because at this point there is no direct evidence that it causes cancer in humans.
Very frequently, regardless of the technical details, many homeowners and citizens in urban areas are considering not using glyphosate in their gardens and landscapes, and they would like to use “safer” herbicides.
What do you mean by “safer?”
If you mean lower risk as a carcinogen, then most herbicides registered for use in urban areas would be acceptable because none of them are considered “probably carcinogenic” by IARC or any other regulatory agency. Therefore, you have multiple options to choose from. However, many of the conversations have lead to the statement, “No, I want something that is less toxic than glyphosate!”
Toxicity in pesticides is predominantly assessed using the lethal dose 50 (LD50), which indicates the amount of a chemical that kills 50% of a reference population of test animals (e.g. mice, rabbits, rats). When the LD50 is high, this means that the chemical has low toxicity, and when the LD50 is low it is considered that toxicity is higher because small amounts of the chemical can cause mortality. Glyphosate has one of the highest LD50s for herbicides. In other words, glyphosate is one of the least toxic herbicides available based on the LD50 standard. Therefore, if we want an alternative herbicide that is less toxic, we do not have any options for urban areas.
What about organic herbicides?
Many people associate “organic” with “safer.” This can be misleading because it depends on how safety is measured. For example, there are multiple organic herbicides that are considered to have the same or even higher toxicity when compared with glyphosate, because many of them have irritant and corrosive properties. Furthermore, organic herbicides have dramatically different herbicidal properties that make them unlikely alternatives to effectively replace glyphosate.
Glyphosate has one of the broadest spectrums of control, so it kills many different weed species effectively. Also, glyphosate works systemically. This means that it is absorbed by leaves and then moves inside the plant to growing points, roots, and other propagating structures. This systemic effect increases the ability to kill relatively large plants. In contrast, the majority of organic herbicides have a contact effect, so they only kill the tissue they touch without being able to move inside the plant. Therefore, they are effective at killing very small plants (<2 inches tall). Large plants can suffer leaf burning after treatment with organic herbicides, and if the application is done properly, the user will see a lot of control shortly after the application (Fig. 1). However, the plants will soon recover and the control level will decrease because, unlike plants treated with systemic herbicides, they can produce new growth from tissues that were not directly expose to the herbicide.
Figure 1. White clover (4 inches tall) control after treatment with glyphosate and twelve different organic herbicides based on natural oil extracts from plants. The green bars represent the level of control 7 days after treatment (DAT) and the yellow bars indicate control 21 DAT.
Considering the lack of alternatives to replace glyphosate, if you want to stop using this herbicide, and you do not want to use any other synthetic herbicides, because their toxicity might be higher, then you need to recognize that weed management will be more challenging. It is unfair to ask lawn care companies or members of HOAs to stop using the tools they have to control weeds and yet expect “weed free” lawns, gardens, and landscapes. Controlling weeds in these scenarios without glyphosate and other synthetic herbicides will require more intensive use of mechanical control approaches and hand weeding. Also, if relying on organic herbicides, these herbicides will have to be frequently applied (probably once or twice a week) in order to kill the weeds at the right time (before they get too big). Also, all these activities will increase weed control costs and the results will likely be not as satisfactory. Thus, you might end up paying more to have lawns and landscapes that will have more weeds escaping control. If this is not acceptable to you, then you probably should be more open to consider the weed control tools we have available. Also, you should be more vigilant about what are the appropriate ways to use them to minimize their risks to humans and the environment, while obtaining the benefits that you are seeking. Otherwise, you should get used to seeing more weeds in the landscape, and to be fair… this might not be as bad as some people think.
by Larry Williams | Jun 22, 2016
MICROIRRIGATION – Image Credit UF/IFAS Extension
When watering to establish a lawn or when renovating (redoing, patching, reestablishing, starting over, etc.) a lawn, we normally call for 2-3 “mists” throughout the day for the first 7-10 days until roots get established. These are just 10 minute bursts. Then back off to once a day for about ½ hour for 7-10 days. Then go to 2-3 times a week for about 7 days. By then your lawn should be established.
If we are experiencing adequate rainfall, you may not need to irrigate. Rain counts. But in the absence of sufficient rain, you’ll need to provide enough water at the correct time to allow your new sod to root – hence, the above directions.
A well designed and correctly installed irrigation system with a controller, operated correctly, helps to achieve uniform establishment. It can be difficult or impossible to uniformly provide sufficient water to establish a lawn with hose-end sprinklers, especially if the lawn is sizeable and during dry weather. Most people are not going to do the necessary job of pulling hoses around on a regular basis to result in a well-established lawn.
Too much water will result in rot, diseased roots and diseased seedlings and failure. Too little water will result in the sod, seedlings, sprigs or plugs drying excessively and failure to establish. The end result at best is a poorly established sparse lawn with weeds. Or complete failure.
There is no substitute or remedy for incorrect irrigation when establishing a brand new lawn or when renovating an entire lawn or areas within a lawn.
It would be wise to not invest the time and money if the new lawn cannot be irrigated correctly. Taking the gamble that adequate (not too much, not too little) rainfall will occur exactly when needed to result in a beautiful, healthy, thick, lush lawn is exactly that – a gamble.
An irrigation system is nothing more than a tool to supplement rainfall. As much as possible, learn to operate the irrigation controller using the “Manual” setting.
The above schedule should help when planting a lawn from seed, sprigs, plugs or sod.
For additional information on establishing and maintaining a Florida lawn, contact your County UF/IFAS Extension Office or visit http://hort.ufl.edu/yourfloridalawn.
by Julie McConnell | Jun 8, 2016
Properly Mowed Empire Zoysiagrass – Image Credit Laurie E. Trenholm
Mowing is an important and often overlooked landscape best management practices that can increase lawn health.
Most of us mowed lawns to earn some spending money as kids. As long as it was shorter when we finished than when we started our customers were happy. Although mowing seems like a simple chore that anyone can do, it turns out that improper mowing can cause a lot of damage to lawns and can increase pest and disease issues.
Make sure your lawn mower in good working order. Ensure the blades are sharp and the engine is not leaking any oil or gas products that may damage your lawn. Dull or damaged blades will give a ragged cut to grass blades that make it easier for disease and insects to attack your lawn. Leaking fuel products can damage or kill turf. Keep your mower clean by blowing or rinsing it after use, this simple step will also reduce the spread of weeds, insects, and disease.
Know the recommended mowing height for your type of turf (see table below) and follow it! Cutting turf below the recommended height places stress on the grass and encourages shallow roots. Deep roots help turf handle stresses such as drought, shade, insects, disease, or traffic. If any of these circumstances are occurring, the mowing height should be increased and fertilization should be decreased.
Mowing Height Table
| Turfgrass Type |
Recommended Mowing Height |
| Bahiagrass |
3.0-4.0 inches |
| Bermudagrass |
0.75-1.5 inches |
| Centipedegrass |
1.5-2.5 inches |
| St. Augustinegrass |
3.5-4.0 inches, Dwarf Cultivars 2.0-2.5 inches |
| Zoysiagrass |
1.5-2.5 inches, cultivar dependent |
When mowing, never remove more than 1/3 of the leaf blade per cutting. If the grass is overgrown, plan to mow in stages to avoid scalping or removing too much of the leaf blade. Just like shrubs, turf needs leaf surface area for photosynthesis. Allow clippings to fall onto lawns rather than catching them or discharging onto hard surfaces. The grass will decompose rapidly and provide nutrients to the lawn. Clippings that are blown onto sidewalks, streets, or other hard surfaces may be washed into storm drains and get into water systems. Just as decomposed clippings provide helpful nitrogen and phosphorus to our lawns, these same nutrients are harmful to our water bodies. Keeping them in lawns is a great way to recycle and to keep our water clean.
To learn more about caring for your turf click on the link below.
Bahiagrass for Florida Lawns
Bermudagrass for Florida Lawns
Centipedegrass for Florida Lawns
St. Augustinegrass for Florida Lawns
Zoysiagrass for Florida Lawns
