 Hi, this is Jim Jacoby, an extension plant pathologist with Alabama Extension. Thank you for joining me today to learn more about common diseases of vegetables. This talk is a part of a series for home gardeners called Grow More, Give More. For more information on this topic, see our website at aces.edu. To start my presentation, I'm going to discuss several tips that will help you manage diseases in the garden. In the second part of the presentation, I'm going to discuss some of the common diseases that I see in backyard vegetables. The first tip is to make sure you start with healthy transplants. Remember, we want to bring nice healthy transplants into the garden and try to avoid introducing any disease from outside sources. So when you're buying plants, inspect the leaves, the stems, the whole plant to make sure that you're purchasing a nice healthy plant. So you want to select short stocky plants with dark green foliage with no visible spots. We want to avoid tall spindly plants or plants with flowers or small fruit. It's important to buy those small to medium sized plants because they're going to become established more quickly than large ones. The next tip is to keep the foliage dry. Avoid overhead watering, especially in the evening. Water on the leaves provides conditions for infection by bacterial and fungal pathogens. And the longer the leaves are wet, the greater the chance that you're going to get infected leaves. Instead, use drip irrigation or water by hand without wetting the leaves, focusing on watering the plants around the base of the plant. Also, try not to walk through the garden when the foliage is wet. You can actually spread disease by picking up spores on your clothing and spreading them from plant to plant. The next tip is to use mulch. Mulch is a great way to slow the spread of fungal spores left in the soil from previous years. That mulch barrier prevents the splashing of spores from debris from previous years up onto the leaves of the plants. Mulch is also great for helping to maintain soil moisture and prevent problems such as blossom endrod on tomatoes. Another tip is to remove infected plant material anytime during the growing season. If you see spots on leaves, or maybe you see a sick plant, pull out the infected plant material. So on the left hand side, we have a few leaves that have brown spots. I'd go in and just cut off those infected leaves and throw them in the garbage. On the right hand side, we have a sick tomato plant. I'd pull the entire plant, even if I don't know exactly what's causing the problem. I'm just trying to be safe and preventing anything contagious from spreading within the garden. The last tip is to do your end of season cleanup. So it's important to revisit the garden at the end of the season to make sure everything is cleaned out. It's essential to go in there and move disease plant residue to reduce free trout breaks. So in this case, we've pulled out the tomatoes. And you can still see that after we pulled out all the tomatoes, there still is some tomato leaves and fruit and pieces of stem that are laying on the ground. I'd go in there with a rake and rake all that material out and remove it, hoping to reduce the chance of having disease the next year. Plus, I'd also go in there and pull any weeds, just to try to also remove the sources of weed seed. Next, let's talk about some of the common diseases you might encounter in the garden. One of the most common is powdery mildew. And it's easily recognized by the white to grayish powdery coating on the leaves. It almost looks like talcum powder has been sprinkled on the leaves. You'll see this on a wide variety of plants. You might see it on your peas, your cucumbers, your cantaloupes, your watermelons. Large variety of plants can be affected. Let's learn a little bit more about the early symptoms and signs of powdery mildew. Powdery mildew often shows up inside the canopy first. So look on the bottoms of the leaves, on the stems or other tissues, because if you can diagnose it and detect it early, you're going to be much better able to manage the disease. Now that we know a little bit more about powdery mildew, let's talk about some control options. One of the first control options is just where you plant the furniture crop. If you plant early and you plant in an open sunny area, you're typically going to have less powdery mildew. Another great option is to use resistant varieties. So if you've had powdery mildew on a crop in the past, maybe it was cucumbers or it was squash, the next time you're going to plant, try to buy a variety that is resistant to powdery mildew. And then you'll have the disease resistance built into the crop and maybe you'll avoid it altogether. The third option is to apply preventative fungicides. So at the first sign of disease, and that means going back to the last slide and looking inside the canopy and on the stems and the bottoms of the leaves, when you first recognize you have some powdery mildew starting, is to apply preventative fungicide. And we know that fungicides containing chlorothalonil, liquid copper, or mycobutanil can be used to control this disease. But before spraying a fungicide, make sure that it's labeled for the crop you're using it on. So in the case of this picture right here, I have some powdery mildew on peas. Before I sprayed or even before I bought a fungicide, I'd want to make sure that it was labeled for controlling powdery mildew and controlling powdery mildew on peas. The next disease we're going to talk about is early blight. Now early blight is our most common foliar disease or leaf disease of tomatoes. And you also may see this on your potato plants. The symptoms of early blight develop on the leaves closest to the ground as small brownish black spots, which can expand to about a quarter to a half an inch in diameter. The spots are relatively regular. They're not perfect circles. And as those spots grow larger, they develop concentric rings, these light and dark rings that almost look like a target or a bullseye. And on the right hand side in this picture, there are some larger lesions or spots, and they're developing that light and dark alternating ring that's typical of early blight. Now early blight is favored by warm wet weather. And so if we have a rainy summer or long periods of rainy weather, we're going to have a lot of early blight potentially, and it can devastate tomato plants. If we have a dry summer, oftentimes we'll have little or no early blight in the garden. To be successful in controlling early blight, we recommend using a combination of methods to prevent disease. First, we recommend rotating to other types of vegetables for two to three years between tomato crops. We also recommend using mulch, which we've discussed before, by creating that barrier with the mulch to prevent the splashing of spores from crop debris and residue from previous seasons. We also recommend using drip irrigation and avoiding overhead sprinklers. So we keep the leaves dry when we use drip irrigation. We also recommend staking, caging, or trellising the plants. So in the picture on the right hand side, we're looking at some tomatoes that are growing on wire cattle panels to get the plants up off the ground, provide better drying conditions, and reduce the amount of disease, hopefully. Another method is to use resistant cultivars. So I've listed four cultivars here. We have Matt's Wild Cherry, Juliette, Defiant, and Mountain Merit. And these would be a way to reduce our use of chemicals, and we can use resistant cultivars as another method to control the disease. But in some seasons when we have a lot of rainfall, we're going to get some disease and we're probably going to need to apply fungicide. I recommend applying the fungicide at the first sign of spots on the plant. We want to start early at the first sign. Don't wait too long. And we apply one of three fungicides that have worked well in research trials. Fungicides containing Magazep, Chlorothalonil, and Liquid Copper. While early blight is the most common disease attacking foliage and tomatoes, other diseases including Septoria leafspot and leaf mold can also be devastating under warm wet weather conditions. So in these two pictures, I have Septoria leafspot on the left-hand side. This also is going to start out attacking the lower leaves first. Symptoms include these small about quarter inch spots that have a dark border with a light center, either white or tan center. On the right-hand side, we have another foliar disease or leaf disease called leaf mold. And leaf mold creates these yellow splotches on the top of the leaf. And then we turn that leaf over, we'll see this green or olive green to brown fungal spores on the bottom. So on the right-hand side, you can see the picture with the yellow splotches on the top and then the spore, the olive green spores on the bottom side. The one good thing is that the control options that we described for early blight will also help to manage both Septoria leafspot and leaf mold. And don't be surprised if you have more than one disease attacking the leaves of your tomato plant. You may have Septoria and leaf mold, you may have early blight and leaf mold, or some combination of those. So you may not just see one disease in your tomatoes. Tomato spotted wilt is a major viral disease that attacks tomatoes, peppers, as well as some ornamental plants. This virus is spread by a tiny insect called a thrips. The insect acquires the virus by feeding on infected weeds or on the hosts and then they pass the virus to tomatoes and other plants when they feed on that plant. Symptoms vary depending on when the plant is infected. Plants infected when they're small are often stunted and turn pale green. These stunted plants may actually wilt and die. Older plants may show leaves that have a purple or bronze appearance. They may have speckling or they may have purple ring spots like as shown in the picture on the right-hand side of the slide. You may also see dark streaks on the petioles and stems of the plant. And an unusual thing that you'll also see is fruit of infected plants will often have these yellow rings. Now that we know a little bit more about tomato spotted wilt virus, let's look at some control options. Before we put the tomatoes in the ground in the springtime, we want to eliminate all weeds in the garden. This is the first step to reducing the chance of getting tomato spotted wilt. Weeds that we know can be carried or hosts of this virus include dandelion, chickweed, buttercup, and planting. So all of these weeds would be ones that I'd really target, but I'd try to get rid of all the weeds in the garden. Another option and probably the best option for preventing the disease is utilizing resistant varieties. Some of the more commonly available varieties for the home garden are Amelia and Bellarosa, but there are many others if you look in seed catalogs. And anytime I see a stunted virus infected plant that has spotted wilt, I'm going to remove that plant. So that's the third way to control it is to remove those infected plants. Thank you for listening to my presentation on vegetable diseases. For more information, visit our website at aces.edu. And if you have additional questions or need help diagnosing a vegetable problem, call our Master Gonder Helpline at 877-252-4769.