by Carrie Stevenson | Sep 30, 2014
Last week, the Okaloosa County Health Department issued a rabies alert after three bats were determined to have the illness. A “drive-through” rabies vaccine clinic was organized for pets, and warnings were issued throughout the region about making contact with wild animals. One radio broadcast played an interview in which a health department staffer urged people “not to attract wildlife to your yard.” While they were focusing on unsecured trash and pet food, I found this advice unsettling, for as an Extension Agent I’ve promoted the practice of attracting wildlife to yards for many years—birds, butterflies, and even (especially) bats. Raccoons, not bats, have the greatest incidence of rabies (based on data collected from 1992-2011), by a factor of almost seven times that of bats. In the scare of a rabies outbreak, it can be easy to overreact or overlook the many benefits that wildlife provide to our neighborhoods.
There are, of course, practical ways to go about living with wildlife without endangering your health or that of your family and pets (including making sure pets have the rabies vaccine).
Use Caution around Injured Wildlife
Most wildlife rescue organizations do not have the staff to pick up injured animals and ask those who find one to bring them in. However, sick or injured animals may respond aggressively as an intuitive protective measure. If you are taking an animal to a wildlife rehabilitator, be sure to approach it gently and use a blanket or large towel to pick up the animal, and place it gently in a box with a ventilated lid. Great information on responding to injured or deserted animals can be found at the Wildlife Sanctuary of Northwest Florida website. Keep in mind that bats are flying animals and spend almost no time on the ground. They do not chase people and are primarily concerned with catching insect prey. If you find a bat on the ground, it is most likely sick. County animal control or private wildlife responders can also help if you are concerned about interacting with a sick animal.
These twin Seminole bat pups were found on the ground with their mother and nursed back to health at the Wildlife Sanctuary of Northwest Florida. Photo credit: Carrie Stevenson
Use Care When Retrieving Dead Animals
When bird flu, West Nile or rabies hits an area, health departments sometimes ask that suspect animals be reported for testing to confirm the cause of death. Even if you are just disposing of the animal, be sure to use gloves and place the animal in a sealable plastic bag to prevent spreading germs, and wash your hands after handling it. If burying, place at least three feet deep and away from wells or water sources.
Enjoy Wildlife from a Distance
Disturbing healthy animals while they are feeding or resting can cause unnecessary stress and reduce their hunting success. Animals’ natural behaviors are fascinating to watch, so be sure and do so from a respectful distance to allow them to interact normally with their environment.
by Matthew Orwat | Aug 4, 2014
Holly leaf infected with Phyllosticta. Image Credit Matthew Orwat
Phyllosticta lesion on holly leaf. Image Credit Matthew Orwat
The high humidity experienced in the Florida Panhandle during July and August has provided perfect conditions for fungal disease development on the leaves of a variety of ornamental species. One particularly noticeable pathogen is Phyllosticta. Fungi of the Phyllosticta spp. often cause large brown lesions on ornamental shrubs and trees such as magnolia, holly, Indian hawthorn, maple, crape myrtle and others. This dark to light brown spots are bordered with maroon, black or yellow rings, dividing the living and dead tissue. Black fruiting bodies, about the size of a pinpoint, are often spread throughout the diseased areas of the leaf. Infected portions of the leaf often drop out, leaving ragged remnants on formerly attractive shrubs.
Although preventative fungicides have been shown to reduce disease incidence, infected plants cannot be cured by sprays. Several mechanical strategies should be put into practice to reduce disease re-occurrence.
- Sanitation: Removal of leaf litter – Dead, diseased leaves contain the fruiting bodies, which will produce new fungal spores if left in the garden
- Thinning of branches – areas with poor air circulation are more prone to Phyllosticta
- Drip irrigation – overhead irrigation enhances the spread of a variety of fungal diseases. If overhead irrigation must be used, it should be done between 5 – 10 a.m.
For additional information about this and other disease, please go to the UF/IFAS U-Scout disease ID site.
Early statge Phyllosticta. Image Credit Matthew Orwat
by Matthew Orwat | Jul 8, 2014
Cedar-Apple rust or Cedar-Quince rust (Gymnosporangium) symptoms on pear fruit. Image Credit Shep Eubanks, UF IFAS.
This is the season for fruit harvesting, particularly for those fruits in the rose family such as plum, quince, peach, pear and apple. Many avid home horticulturists have been enjoying the fruits of their labor, but some have been thwarted by an unlikely and ugly disease.
This fungal disorder, commonly called cedar-apple rust and caused by various species of Gymnosporangium, has the potential to ruin Quince, Pear and Apple crops in gardens throughout Northwest Florida. Early scouting and vigilance will pay off.
This condition begins on native juniper species (known as cedars). A spore producing gall forms on the branches of the cedar tree, which begin to produce spores during wet weather. Spores, once produced, can travel up to a mile via wind. If spores land on susceptible plant tissue when a film of water is present, it will germinate and infect the fruit, twig or leaf. Although black spots develop on the plant with in 7-10 days of infection, orange tubes called aecia won’t develop until 4 or more weeks after infection. Next, spores are released from the aecia located on the fruit tree and travel to infect new juniper plants . The infected junipers will not show symptoms until the next growing season but they can manifest as galls or orange ooze present under bark. Different species of Gymnosporangium will infect trees differently. Some live only for one year while others, known as ceder-quince rusts, can last up to 20 years. Twigs infected with this disease usually die within several years of infection.
Ceder-Apple Rust on infected juniper host species. Image Credit Hank Dankers UF IFAS.
Although this may seem like an impossible situation, several control strategies exist.
- Remove Infected branches: Removal of infected plant tissue will reduce the spread of the disease in your garden.
- Removal of infected juniper host species: If the juniper or “cedar” in your landscape is something you can sacrifice, removal is warranted in cases of heavy infection.
- Avoid planting susceptible species of juniper next to susceptible fruit tree species.
- Treatment of fruit trees with fungicide: Preventative fungicidal sprays of products containing the active ingredients of sulfur, captan, chlorothalonil, or mancozeb and similar products can be effective. They will not cure existing conditions but are useful if you know that rusts are present in your area. Please read all pesticide labels before application, since there are pre-harvest limitations present on some products.
For additional information, please consult you local county extension office or review these publications by UF IFAS specialists (Florida Plant Disease Management Guide) and the Missouri Botanical Garden.
by Eddie Powell | Jul 1, 2014
Tomato spotted wilt on leaves
Photo Credits: IFAS
Tomato Spotted Wilt on Fruit
Photo Credit: IFAS
The spotted wilt virus has a wide host range and can affect tomatoes, peppers, plus many other vegetables and ornamental plants. Early symptoms of spotted wilt on tomato are difficult to diagnose. Young, infected plants may show an inward cupping of leaves, and the foliage may appear light color or have a slight bronze cast. As the disease progresses, plants may develop dark brown to black streaks on the main stem. Occasionally the top portion of the plant appears yellow or wilts.
The most characteristic symptom of spotted wilt appears on the fruit. On young fruit white to yellow concentric rings will develop on the fruit skin. The area within the ring typically is raised, which gives the fruit a bumpy appearance. The bright yellow rings on mature red fruit are easily diagnosed as spotted wilt.
The spotted wilt virus is transmitted from plant to plant by several species of a small insect called a thrips. Thrips are less than ¼ inch in length, light green to brown in color and are extremely difficult to find on the plants. It is very important to keep the weeds around the garden controlled because many weedy plants serve as alternate hosts for the virus vectors.
Virus diseases cannot be controlled once the plant is infected. So plant resistant varieties*! Sanitation will help with controlling virus diseases. Infected plants should be removed immediately to prevent spread of the pathogens. Perennial weeds, which may serve as alternate hosts, should be controlled in and adjacent to the garden. Avoid planting tomatoes next to peppers, or other vegetables and flowers susceptible to these diseases. Preventative control of insects, especially thrips, will help reduce the likelihood of spotted wilt.
*BHN 602, Amelia, Crista, Quincy, Bella Rosa, Top Gun, Fletcher, Mountain
by Eddie Powell | Jun 3, 2014
During this growing season monitor your plants and keep them healthy as a healthy plant will be able to better survive an invader attack.
Nematode populations can be reduced temporarily by soil solarization. It is a technique that uses the sun’s heat to kill the soil-borne pests. Adding organic matter to the soil will help reduce nematode populations as well. Nematodes are microscopic worms that attack vegetable roots and reduce growth and yield. The organic matter will also improve water holding capacity and increase nutrient content.
Tomato Spotted Wilt Virus
Credits: UF/IFAS
If you choose to use pesticides, please follow pesticide label directions carefully. Learn to properly identify garden pests and use chemicals only when a serious pest problem exists. If you have questions please call your UF/IFAS county extension office. We can provide helpful information about insect identification.
Organic gardeners can use certain products like BT(Dipel) to control pests. Please remember not every off-the-shelf pesticide can be used on every crop. So be sure the vegetable you want to treat is on the label before purchasing the product.
Follow label directions for measuring, mixing and pay attention to any pre-harvest interval warning. That is the time that must elapse between application of the pesticide and harvest. For example, broccoli sprayed with carbaryl (Sevin) should not be harvested for two weeks.
Spray the plant thoroughly, covering both the upper and lower leaf surfaces. Do not apply pesticides on windy days. Follow all safety precautions on the label, keep others and pets out of the area until sprays have dried. Apply insecticides late in the afternoon or in the early evening when bees and other pollinators are less active. Products like malathion, carbaryl and pyrethroids are especially harmful to bees.
To reduce spray burn, make sure the plants are not under moisture stress. Water if necessary and let leaves dry before spraying. Avoid using soaps and oils when the weather is very hot, because this can cause leaf burn.
Control slugs with products containing iron phosphate.
Cucumber Mosaic Virus
Credits: UF/IFAS
Many common diseases can be controlled with sprays like chlorothalonil, maneb, or mancozeb fungicide. Powdery mildews can be controlled with triadimefon, myclobutanil, sulfur, or horticultural oils. Rust can be controlled with sulfur, propiconazole, ortebuconazole. Sprays are generally more effective than dusts.
by Sheila Dunning | May 13, 2014
Last summer’s heavy rain and the stress of January’s icy weather have contributed to widespread outbreaks of Take-All Root Rot, a soil-inhabiting fungus Gaeumannomyces graminis var. graminis that causes yellow grass patches ranging in diameter from a few inches to more than 15 feet. The symptoms first appear in the spring, but 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. Because 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; potentially years. If the turfgrass is not stressed, leaf symptoms may never be observed.
This disease is very difficult to control once the above-ground symptoms are observed. Measures that prevent or alleviate stress are the best methods for controlling the disease. Any stress (environmental or man-made) 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 issues. 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 saturate 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 – 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. But, 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.
Now that we have added another major stress with the recent heavy rain, it will be very important to continue monitoring the turf and being cautious about the cultural practices being used. Take-All Root Rot is likely to flourish. Do not encourage its development.
