Fall Vegetable Gardening Workshop August 6
Peppers Get Tomato Spotted Wilt Virus Too!
Peppers and tomatoes are in the same plant family – solanaceae or more commonly known as the nightshade family – and can be susceptible to some of the same diseases. This is true of Tomato Spotted Wilt Virus (TSWV). The solanaceae family includes potatoes, eggplant, tobacco, petunia, tomatillo and deadly nightshade in addition to pepper and tomato.
Pepper with TSWV. Photo credit: Mary Derrick, UF IFAS Extension.
This virus is spread by very small insects known as thrips. They acquire the virus as larvae when feeding on an infected plant and then transmit the disease when they fly to other susceptible plants as adults.
Initial symptoms are yellowing and distortion of the leaves. The leaves can also display yellow or brown circular ring spots. The severity of the virus can depend on the particular cultivar of pepper, its age and the environmental conditions in which the pepper is growing. Fruit can develop yellow, brown or ring spots as well.
TSWV infection showing ring spot on leaves and lesions on fruit. Photo credit: Mary Derrick, UF IFAS Extension.
If you think your pepper has TSWV, consult your local extension agent to confirm the diagnosis. But once infected, there is no treatment for the plants and they should be pulled up and disposed of in the trash to prevent other susceptible plants from becoming infected.
For more information:
Some Common Diseases of Pepper in Florida
Do Your Plants have Problems?
When you don’t know what’s ailing your plant, ask an expert.
Many gardeners get stumped when a favorite plant of theirs comes down with a strange “something”. Many of these gardeners know about UF/IFAS Extension and call their local horticulture and agriculture agents for assistance in figuring out what’s going on. However, even these experts are often stumped by what they see. Fortunately, the agents have another layer of experts to fall back on. In addition to the resources in Gainesville, we have the Plant Disease Diagnostic Clinic, located at the North Florida Research Center in Quincy. Plant pathologists here can help determine what fungus, bacteria, virus, or viroid may be the problem.
Plant pathologists are basically plant doctors. They use all sorts of sophisticated techniques to determine what is the cause of a particular plant problem, from growing out fungal spores to examining DNA. Not only do these plant doctors tell us what the ailment is, they also provide recommended cures, or control options. They are also doing research to prevent different diseases from taking hold in our area and reduce the impact on our local growers.
Plant pathologist at work!
At a recent workshop in Quincy, we learned that plant pathology researchers are working on a fungus that affects watermelons, virus and bacteria that can wipe out a farmer’s tomato crop, and a virus that could impact our local roses. Working as a team of scientists, they study these pathogens in the lab and conduct controlled field experiments to figure out which techniques are most effective. Some of this research is leading to different methods and/or products that can help growers and gardeners alike keep their fields and landscapes healthy.
So, if your plants have problems, please contact your local Extension Office. If they don’t know the answer, then the network of scientists, including plant pathologists, in the UF/IFAS Extension family can be called on for backup to provide you with the best possible answer.
Control Grasshoppers When They Are Young
Young nymphs of the eastern lubber grasshopper, Romalea microptera (Beauvois), clustered on a citrus reset (young citrus tree). Photograph by John Capinera, University of Florida.
The Eastern Lubber Grasshopper, also known colloquially as the “Georgia Thumper,” can be highly destructive to a variety of vegetable crops. This May many growers and vegetable gardeners have reported unusually high numbers of nymphs, the juvenile form of the grasshopper.
This observation is consistent with the usual increase of nymphs in vegetable gardens during the spring months. The old adage of “an ounce of prevention is worth a pound or cure” applies here. Now is the time to exert control over the nymphs before they mature. Adults do the greatest crop damage in July and August.
Additionally, adult females lay their eggs in the summer, with hatching the following April. Reducing the numbers this year will reduce the numbers in the following years.
The first step to control of the Eastern Lubber Grasshopper is prevention. They like to feed on weedy vegetation, so reducing weed cover in and around crops will reduce the incidence of Eastern Lubber damage. Short vegetation does not usually provide enough forage for grasshoppers, so mowing vegetation around fields is an excellent preventative strategy.
Although most home gardeners can control Eastern Lubber Grasshoppers by mechanical means (hand picking) this is usually not a feasible option for large gardens or small farm plantings. Fortunately, there are several products on the market for commercial producers to use.
Keep in mind, grasshoppers are much easier to control while they are in the young nymph stage, so early action is paramount when nymphs are observed. Several effective insecticides include carbaryl, bifenthrin, cyhalothrin, permethrin, and esfenvalerate. Look at the label to find these active ingredients, since they are sold under various brand names.
For more information about the Eastern Lubber Grasshopper or for specific crop recommendations, please visit this UF/IFAS publication on Grasshoppers and the UF/IFAS Featured Creatures Entomology Page.
What’s in Your Manure?
Humans have used animal manures to fertilize food crops for thousands of years. Manures are an organic source of plant nutrients and are often a waste byproduct that must be properly managed when raising animals. Today, many farmers and backyard gardeners continue to use animal manures to provide nutrition to their crops. However, a recent experience at our local extension office brought to our attention the need to know what else, besides nutrients, is in the manure used.
A local backyard gardener brought in samples of tomato plants that had strange new growth. She had purchased the tomato plants, along with other vegetable plants, from a local nursery. When she repotted the tomato plants into larger pots, she added horse manure from her own horses to the soil mix. She then noticed this strange growth on the tomatoes, but not in the other vegetable plants that were repotted without adding horse manure. Herbicide damage was one of the first potential causes we suggested, since the new growth was twisted and distorted, a common symptom of plants that have been sprayed by herbicides. The gardener was sure she had not sprayed any herbicides near these plants, or in the pasture where she keeps her horses.
Herbicide damaged tomato plants. Photo by: Mark Tancig
Photos of the tomato plants were shared with other NW District agents and an agriculture agent with livestock and hay producer experience had the probable answer – herbicide damage due to the horses being fed hay from a hayfield that was treated with a particular herbicide. Interestingly, this agent also had experience with these symptoms after their neighbor had similar issues using manure to fertilize the garden.
Herbicides with the active ingredients picloram or aminopyralid are able to cause this kind of unexpected damage to many gardeners’ crops. Herbicides containing these active ingredients are used in hayfields to control broadleaf weeds. These herbicides are especially effective at controlling hard to manage weeds such as thistle, nightshade, and nettle. They also provide long-lasting weed control. Unfortunately, the persistence of these ingredients extends into the hay, and also persists in the manure and urine of animals who eat hay from treated fields. These ingredients pass through the animal unchanged and remain active as an herbicide. Since many vegetable crops are broadleaf plants, the herbicide’s ingredients cause injury.
So what can a farmer or backyard gardener do to prevent this problem? When purchasing hay for livestock, ask the seller if they know whether the hayfield has been treated with herbicides that contain either picloram or aminopyralid. Most herbicides are known by their common names, rather than their chemical name. If they give you a common name or brand name, the active ingredient can be obtained by contacting your local extension office. If the seller can’t tell you, then, as a precaution, do not use the manure to fertilize broadleaf vegetable crops. The same question should be asked if purchasing hay for mulch as well. Composting the manure or hay does not break down the active ingredient, and may even concentrate it.
While we continue to use animal manures to fertilize our crops as our ancestors did, it’s important to remember that many of the tools and products we use today are much more advanced. These advanced products require that we stay informed of all precautions, use them responsibly, and, in this case, inform end users of any precautions. Remember to always read and follow the label and ask questions. And if a science-based answer is what you’re looking for, your local extension office is a good place to go!
Warning from herbicide label.
Caterpillars in the Vegetable Garden
In the last few weeks, more garden pests have arrived! It is a fact of life in northwest Florida that we will have a few things in our garden including heat, moisture (humidity and rainfall), and BUGS! With a cooler spring the arrival of some of the troublesome pests in the garden seemed to be delayed a few weeks. It was nice while it lasted but the insect pests are here to stay until frost in the fall or winter (at least we hope for a frost this year).
There are thousands of insects that you can see in your garden. It’s wise to identify them before making a decision to spray an insecticide or remove them by another method. Insect samples can be taken to your local county extension office for identification.
In this article we will just discuss one of the top insect pests in the vegetable garden, caterpillars, and what you can do about them.
Mature larva of the cabbage looper. Photograph by John L. Capinera, University of Florida.
Beet armyworms, fall armyworms, hornworms, cabbage loopers, southern armyworms, tomato fruitworms, and other caterpillars love to feed on tomato foliage and fruit. They will show up eventually on tomato plants in the garden, if not this year then in the future. These larvae are immature moths and cause a lot of damage if left unchecked. The homeowner can control them effectively with Organic Materials Review Institute (OMRI) approved pesticides. A bacterial biological insecticide called Bacillus thuringiensis, also referred to as B.t., can be very effective in controlling these caterpillar pests. B.t. is a stomach toxin to these pests and will cause them to quit eating and starve to death. The key to using B.t. effectively is to routinely apply it before the caterpillars hatch from their eggs as the smaller caterpillars are easiest to control. Larger caterpillars are more difficult to control.
For more information related to using OMRI pesticides:
Organic Vegetable Gardening in Florida
Insecticides for Organic Commercial & Backyard Vegetable Production