by Matt Lollar | Sep 23, 2015
Armyworms come in a wide range of colors and sizes. A few of the prominent species living in Florida are beet, southern, and fall armyworms. And the term “living” is not an exaggeration, because Florida is one of the lucky states where it is warm enough for armyworms to overwinter. They are the snowbirds that never leave!
Armyworm damage on a lawn. Credit: Purdue University
Armyworms are notorious for unanticipated invasions. They feed on most turfgrass species and most vegetable crops, but they prefer grassy vegetable crops such as corn. Armyworms feed in large groups and their feeding has been described as “ground moving” in lawns. They feed during cooler times of the day (morning and evening) and they roll up and rest under the vegetative canopy (in the thatch layer in turf and in the base of leaves in vegetables) during the heat of the day.
Armyworms 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. A good weed control program can also help to deter armyworms, because weeds serve as an alternate food source.
Numerous chemical control options are available, but softer chemicals such as horticultural oils and 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 Armyworm Publication Page.
Armyworm feeding on a young corn plant. Credit: University of Illinois
by Sheila Dunning | Sep 16, 2015
“We have replaced this grass several times over the past few years; and it’s dying again.” I have heard this complaint too many times this summer. Last summer’s heavy rain, the stress of January’s icy weather, and this year’s extended summer have contributed to widespread outbreaks of Take-All Root Rot, a soil-inhabiting fungus Gaeumannomyces graminis var. graminis.
Symptoms of Take-All-Root-Rot. Photo credit: Sheila Dunning, UF/IFAS.
This disease causes yellow grass patches ranging in diameter from a few inches to more than 15 feet. The symptoms first appear in the spring, but the disease can persist all summer and survive the winter. Over time, the entire area dies as the root system rots away. The pathogen is naturally present on warm-season turfgrass roots. High rainfall and stressed turfgrass trigger the disease.
Since the roots are affected, they are not able to efficiently obtain water or nutrients from the soil, nor are they able to store the products of photosynthesis, which result in the loss of color in the leaves. By the time the leaf symptoms appear, the pathogen has been active on the roots for several weeks, probably longer; the disease has been there potentially for years. If the turfgrass is not stressed, leaf symptoms may never be observed.
This disease is very difficult to control once the aboveground symptoms are observed. Measures that prevent or alleviate stress are the best methods for controlling the disease. Any stress (environmental or manmade) placed on the turf weakens it, making it more susceptible to disease. Remember, that every maintenance practice, fertilizer application, and chemical (especially herbicide), application has an impact on turfgrass health. Cultural practices that impact the level of stress experienced by a lawn include:
- proper turfgrass species selection
- mowing at the correct height
- irrigation timing, frequency and volume
- fertilizer: nitrogen and potassium sources and application quantities
- thatch accumulation, and
- soil compaction
The selection of turfgrass species should be based on existing soil pH, sunlight exposure, use of the area and planned maintenance level.
Mower blades must be sharp to avoid tearing of the leaves. Additionally, turfgrasses that are cut below their optimum height become stressed and more susceptible to diseases, especially root rots. When any disease occurs, raise the cutting height. Scalping the grass damages the growing point. Raising the cutting height increases the green plant tissue available for photosynthesis, resulting in more energy for turfgrass growth and subsequent recovery from disease.
If an area of the lawn has an active fungus, washing or blowing off the mower following use will reduce the spread of the disease to unaffected areas.
The amount of water and the timing of its application can prevent or contribute to disease development. Most fungal pathogens that cause leaf diseases require free water (rainfall, irrigation, dew) on the leaf to initiate the infection process. Irrigating every day for a few minutes is not beneficial for the turfgrass because it does not provide enough water to the root zone, but it is beneficial for turfgrass pathogens. It is always best to irrigate when dew is already present, usually between 2 and 8 a.m., and then only apply enough water to wet the root zone of the turfgrass.
Excessively high nitrogen fertility contributes to turfgrass diseases. The minimum amount required for the grass species should be applied. Potassium (K) is an important component in the prevention of diseases, because it prevents plant stress. Application of equal amounts of nitrogen and potassium is recommended for turfgrass health. When turfgrass roots are damaged from disease, it is beneficial to apply nutrients in a liquid solution. However, nitrate-nitrogen increases the severity of diseases, so their use should be avoided when possible. Ammonium-containing fertilizers are the preferred nitrogen sources.
Heavy liming has also been linked to increases in Take-All Root Rot. Since most turfgrasses can tolerate a range of pH, maintaining soil at 5.5 to 6.0 can suppress the development of the pathogen. When the disease is active, frequent foliar applications of small amounts of nutrients is necessary to keep the turfgrass from declining.
Additional maintenance practices that need to be addressed are thatch removal and reduction of soil compaction. Excessive thatch often causes the mower to sink which can result in scalping and reducing the amount of leaf tissue capable of photosynthesizing. Thatch and compacted soil prevent proper drainage, resulting in areas remaining excessively wet, depriving root systems of oxygen. Since recovery of Take-All-Root-Rot damaged turfgrass is often poor, complete renovation of the lawn may be necessary. Removal of all diseased tissue is advised.
As a native soil-inhabiting pathogen, Take-All-Root-Rot cannot be eliminated. However, suppression of the organism through physical removal followed by proper cultivation of the new sod is critical to the establishment of a new lawn. Turfgrass management practices, not chemicals, offer the best control of the disease.
It is acceptable to use fungicides on a preventative basis while rooting in the sod. Azoxystrobin, fenarimol, myclobutanil, propiconazole, pyraclostrobin, thiophate methyl, and triadimefon are all fungicides that can be utilized to prevent disease development while having to excessively irrigate newly laid sod. Ideally, the turf area should be mowed and irrigated prior to a fungicide application. Unless the product needs to be watered in, do not irrigate for at least 24 hours after a chemical treatment. Do not mow for at least 24 hours, to avoid removal of the product attached to the leaf blades.
With all the stresses that our lawns have experienced, it is very important to continue monitoring the turf and be cautious about the cultural practices being used. Take-All Root Rot is likely to flourish. Do not encourage its development. A pathology test with the University of Florida Laboratory can confirm the presence of the disease causing organism. Before resodding again, have the dying sod tested.
For information and the submission form go to:
Sample Submission Guide
For more information on the disease go to:
Take-All-Root-Rot
by Carrie Stevenson | Aug 26, 2015
About two years ago, my son was mowing the lawn when he came across something orange and furry lying in the grass. He backed away and yelled for his dad, but the damage had already been done—he had come across the remains of our orange tabby cat, killed overnight by a larger predator. Emotional repercussions aside, it was startling for our family to realize that even in a residential neighborhood within the city limits, animals were hunting nearby. Based on the experience of seeing one in our own yard just a few months earlier and from other neighbors’ stories, we realized we’d had a coyote attack. Our neighborhood is located relatively close to a large wooded area and a local bayou, and there are plenty of places for coyotes to find shelter.
Always feed your pets indoors and keep them inside at night to prevent coyote attacks. Photo credit: Carrie Stevenson
We learned several lessons after our incident that could be helpful to others living in areas populated with coyotes. Like sharks, coyotes are crepuscular creatures—most actively feeding at dusk and dawn. While they prefer to eat small animals like lizards, rodents, and young birds or deer, they are omnivorous and will also eat fruit and grasses. Not unlike other urban wildlife such as raccoons, they are opportunistic feeders and will scavenge dead animals and garbage. One of the best ways to protect small pets is to keep them (and their food) indoors at night and early morning. Pet food left outdoors often attracts coyotes’ normal prey and therefore the coyotes themselves. It is extremely rare to hear of a coyote attacking a human, but if threatened it is recommended that you yell, throw something, or spray a water hose. Stand your ground and fight back—don’t run, as this will encourage them to give chase.
Coyotes are social animals and often hunt in packs, and like the dogs they’re related to, have excellent vision, hearing, and sense of smell. They will howl and bark to communicate with one another, and hearing these vocalizations is often the first sign that there are some living nearby.
Coyotes are common throughout Florida. Photo credit: W. M. Giuliano
Floridians are no strangers to living with wild animals—we all routinely hear stories of alligators, black bears, venomous snakes, and sharks interrupting our attempts at taming the former wildlands that we now occupy. As urban development marches through the landscape, the large tracts of land once used primarily by animals for hunting and shelter are occupied by human dwellings and transportation routes.
While coyotes are relatively new to Florida (they are native to the western US but entered northwest Florida in the 1970’s), they’ve filled in the ecological gap left by a reduction of native wolves, bobcats, and panthers. Research has shown they now reside in every Florida county and can range the entirety of North America and most of Central America.
Most homeowners will never encounter a coyote, but it is helpful to know they are out there and to take precautions with pets and yard practices to prevent attracting one into your backyard.
For more information on managing coyotes, please visit the UF publication Managing Conflicts with Wildlife: Living with Coyotes.
by Mary Salinas | Aug 19, 2015
When you know that your lawn needs an application of fertilizer, herbicide, insecticide or fungicide, the question becomes how much to buy and put down. For these products, success stems from applying the right amount, not too much or too little. The label on those products always tells the consumer how many square feet of lawn can be treated, but how do you figure that out?
You could always do it the old-fashioned way with measuring tape and a calculator, estimating the angles and the areas of those curvy, irregular flower beds. This method takes a bit of time and you will still wonder about the accuracy of your final numbers.
Here’s an easier, and more accurate way to do it!
Sod Solutions, Inc. offers an online tool that is easy to use and very accurate. Enter your address and GPS locates the aerial view of your property. Create an overlay by plotting points and the square footage is automatically calculated. The instructions under ‘How to Use the Calculator’ are very clear and makes this tool so easy and convenient to use.
For more information on lawn care topics:
Gardening Solutions: Lawns
by Les Harrison | Aug 11, 2015
Weeds are growing everywhere, especially in manicured lawns and landscapes despite the best efforts of owners who have spared no expense to remove the offending flora. Herbicides to control the weeds seem to be less effective as August progresses.
The reality, at least about the herbicides, is different from perceived appearances. Herbicides can be a wonderful tool for the homeowner, if applied properly.
[important]The first point to remember about herbicides is to always, Always, ALWAYS apply them as instructed by the label directions. The oft quoted mantra of “the label is the law” is accurate.[/important]
Herbicides and their labeling are periodically reviewed and assessed to confirm effectiveness against target weeds without damaging the environment. Not following the label directions can have many negative implications for both the environment and the applicator.
Herbicides are either selective or non-selective when killing plants. Non-selective herbicides kill or damage every plant, but selective herbicides target a narrower range of plants.
Chamberbitter, a common annual weed. Photo credit: Mary Derrick, UF/IFAS Extension.
Never apply herbicides when there is a breeze or wind. Herbicide drift can injure or destroy plants that are not the intended target.
High temperatures can contribute to the drift problem by volatizing some of the herbicide spray. Even the lightest air movement will cause drift off the target weeds when this condition exists. Herbicide drift can also be deposited in ponds and streams, harming the aquatic creatures that live there. Some herbicides are toxic to fish, insects and other animals that can be killed by tiny amounts of the active chemical. Additionally, the off target herbicides can kill aquatic plants. When the dead plants decay, they deplete the water of oxygen, again threatening or ending the life of the water’s residents.
Rain or dew resulting from high humidity can negate a herbicide’s application. If a leaf is wet, most or all the herbicide will run off on to the soil where it can leach into the water table.
Unless stated on the label, herbicides work only when the plant is actively growing. A hot, dry week or two can put a plant in drought mode, suspending growth and the herbicide’s effectiveness.
Many weeds have already produced seeds for next spring. Herbicides applied now will not affect the germination of that seed months from now.
The most effective strategy is to mow weeds before they set seed or to collect and destroy those which have already produced seed. Even with 100 percent success at eliminating this year’s weed seed crop, there will be weeds next year.
Some weed seed remain in the soil, sometimes for decades, only to germinate when conditions are perfect for their sprouting. Sickle pod and crotalaria are local examples of long term seed vigor.
Other seed can blow in or be dropped by wild or domestic animals passing through the property. A pre-emergent herbicide which stops germination can help control these latent invaders.
For more information:
Weed Management Guide for Florida Lawns
Gardening Solutions: Weeds
