Tag Archives: tomato disease

Tomato Tips: Preventing Fungal Diseases

For many tomatoes are the highlight of the summer garden. The refreshing sweet yet acidic flavor of a garden tomato is world’s away from the bland, mealy supermarket tomatoes of winter. Unfortunately for those living in areas with hot, humid summers getting a good tomato harvest can be a struggle. Many times tomatoes can become afflicted with fungal diseases like Verticillium wilt, Fusarium wilt, or Alternaria.

Alternaria also known as early blight causes “bullseye” leaf spots and can causes lesions on the fruit. Fusarium wilt causes the plant’s leaves to wilt and turn yellow and then brown. It usually begins on the plants lower leaves. Like Fusarium wilt, Verticillium wilt begins at the bottom of the plant causes yellow spots to form on the leaves before the leaves turn fully yellow or brown.

There are also many other tomato afflictions you could be experiencing in your garden these are just a few common ones. 

Don’t handle your tomatoes when they’re wet.

Fungal diseases are passed through moisture. Avoid working with your tomato plants until after all the dew or rain had dried off.

Use drip irrigation.

Using drip irrigation is more efficient and can help limit the spread of fungal diseases because the water is going directly to the plants’ roots. For those with small gardens, it’s also possible to spot water the base of the plant. If you must use overhead watering water in the early morning so that the plant will have time to dry off during the day.

Tomato trellis of string weaving at Twin Oaks Community Farm

Prune, trellis, and weed around your plants.  

We all start each spring with the best intentions but often the summer gets away from us. It can be easy to fail to keep up with these important tasks when our garden is competing for our attention with work and family obligations. However, maintaining good airflow around your plants is vital to preventing fungal diseases.

Tomatoes can be trellised in a variety of manners like the “Florida weave” pictured above, on cattle panels, or some sort of homemade tomato cage.

Rotate your crops.

Many fungal diseases that afflict tomatoes live in the soil. To keep your tomatoes disease free you must rotate your crops. Don’t plant tomatoes or other nightshades (including potatoes, peppers, and eggplants) in the same space multiple years in a row. You should use a minimum of a four-year rotation.

Keep your soil and plants healthy.

Along with rotating your crops, you should also work hard to improve your soil’s health which will help you grow healthier, less vulnerable plants. Get your soil tested and add amendments as needed. Practice no-till agriculture. Use cover crops and good quality compost to add fertility and organic matter to your soil. Mulch pathways and around plants to add organic matter and habitat for beneficial fungi and microbes.

West Virginia 63 (Centennial) Tomato – resistant to late blight, Fusarium wilt race 1, Verticillium wilt, and sunscald

Plant disease resistant varieties.

Some varieties have been specifically bred to better tolerate these diseases. Check out our disease resistant selection.

Try a fungicide.

If all else fail you can find organic fungicides. Look for those that are OMRI (Organic Materials Review Institute) listed. Keep in mind that organic doesn’t always mean completely harm-free. Many fungicides will kill off your soils’ good fungus as well as the bad. Some fungicides like copper can even cause toxicity in your soil if used too frequently or in high quantities! Some gardeners have luck with products like Mycostop which are created from bacteria that feeds on the fungus.

Having tomato diseases ruin your harvest can take a lot of the fun out of gardening. Try following these tips to keep your tomatoes disease free this year.

 

Sustainable Agriculture Research Stations

Continuing our summer road trip adventures! Besides seed growers, we also visited with many vegetable breeders and researchers on our trip.  Here we’ll profile four organic and sustainable agriculture research stations.

North Carolina State University’s Mountain Research Station in Waynesville, NC (near Asheville) is up in the hills, and cooler and wetter than most of NC – a great place for tomato disease trials! Here, Luping Qu, Reuben Travis, and Jeanine Davis discuss how to measure the effects of diseases for their trial notes.

There’s a lot going at the Mountain Research Station. Besides tomato trials, we got to see melon and squash trials, stevia trials, hops trials, organic broccoli variety trials, and much more – here’s an overview of this year’s research projects. And that’s just the Alternative Crops and Organics part of the farm – elsewhere on the farm, there’s a big broccoli varieties trial that’s part of a multi-state project that aims, among other things, to find broccoli varieties that hold up well in the heat of the Southeast.

A great practice at the Mountain Research Station farm (and at many other farms we visited) is to plant strips of flowers and herbs — usually on the edges of fields, but sometimes in the middle as well. These flowers and herbs help attract pollinators and bug predators.

Jeanine is the co-author of Growing and Marketing Ginseng, Goldenseal and Other Woodland Medicinals. Her blog about the work at the Mountain Research Station is a great read. She’s a dedicated outreach person, and besides giving talks at the Carolina Farm Stewardship Association’s Sustainable Agriculture Conference, she regularly speaks at many conferences, including this year’s Heritage Harvest Festival at Monticello, September 11-12.

A quick stop was the University of Tennessee’s East Tennessee Research and Education Center in Knoxville. We were already visiting three different Tennessee farms that day, but there it was, only a couple miles away from Jonathan Buchanan’s Crooked Road Farm, so we dropped in for a quick look. Much of the farm’s work is giving young beginning farmers experience growing market crops, but we also got to see pepper trials, stevia trials, and – a great new vocabulary word – ratooning trials for kale and other crops in the brassica family. Ratooning is the practice of severely cutting back plants to stimulate new growth for later production. Okra growers in the Deep South often do it, so as to keep okra plants from getting 10 feet tall or more! Here’s a ratooned kale crop at the East TN Research and Education Center.


Next was the USDA’s U.S. Vegetable Laboratory in Charleston, South Carolina, with Clemson University’s Coastal Research and Education Center (CREC) nearby. Mark Farnham and Richard Fery with the USVL, and Brian Ward (at left below) with the CREC, showed us around. Here Mark talks about his work with breeding summer broccoli that holds up in July heat. Vegetable breeding is patient work – it can take planting out big fields of dozens of different breeding lines to find the best traits. This was July, swelteringly hot in Charleston, but there was some great looking broccoli out there – Mark’s hoping to release some of the breeding lines in the next few years!

Mark (at right below) is a brassicas guy; another recent project of his and Pat Wechter’s, Carolina Broadleaf mustard, is a leafy green bred for resistance to a bacterial leaf blight that’s become a problem in the Deep South. The USVL makes small amounts of breeding stock available to seed producers, so we’re hoping to line up some of our own seed growers for this one and have it in the SESE catalog in the next few years.

Richard Fery is emeritus plant geneticist at the USVL. He’s worked on many different seed crops over the years, mostly peppers and southern peas. He and his colleagues bred the nematode-resistant Carolina Wonder sweet pepper, Charleston Hot hot pepper, and many others, and he’s shared seedstock with us of southern peas releases that we’re hoping to be able to offer in the next few years.  He’s in the picture below at right, with colleague Floyd P. Maguire at left.

Across the street, Brian Ward gave us a fast tour of the organics section of Clemson’s Coastal Research and Education Center. Interesting projects included watermelon seedlings grafted onto gourd rootstock for greater disease resistance and vigor, a study of alternative pollinators for watermelons, rice trials, and seed increases for heirloom varieties of peanuts, southern peas, and corn. Alas, so much to see, but so little time!

Our final stop in the research portion of this trip was the Cherry Farm facility in Goldsboro, NC, for the Center for Environmental Farming Systems (CEFS), a collaboration between several NC ag departments. With 2,245 acres available, CEFS has a huge area to do all kinds of big studies, with long term studies of soil nutrition, tree alley crops, forest succession, animal husbandry, and many others. Research Operations Manager Andy Meier generously took time on a Sunday afternoon to show us around. CEFS helps provide the space and support for many NC ag folks and groups to do trials.  Their variety trials this year include wheat, barley, soybeans, and this southern peas trial with four repetitions. Again, so much to see, and so little time!

Next week we’ll spotlight two individuals who we visited who breed exciting new varieties.