Tomato Verticillium Wilt (VWR)
The tomato is one of the most widely grown vegetables worldwide. It was introduced into the United States in 1823 by John Chapman, who brought it back to England where he sold them at fairs and markets. They were first cultivated commercially in California in 1846 when William Fosdick planted some seeds on land owned by Charles Moore, a well known gardener and owner of the San Francisco Horticultural Society. In 1851, William Fosdick’s son, George Fosdick, began selling tomatoes in San Francisco.
In the early 1900s, many varieties of tomato were developed and marketed. By the 1960s there were over 200 different types of tomato grown commercially in North America. Today there are approximately 4 million acres of commercial tomatoes growing in the U.S., Canada and Mexico.
Although the tomato is considered a low-maintenance vegetable, it still requires care. A few factors contribute to its susceptibility to disease:
Varieties vary greatly in size and shape; they do not all grow equally well or even at all. Some have short stems while others are tall and slender. Some produce large fruits while others may only yield small ones. The skin of some varieties tends to rot before the fruit does due to their high water content and poor drainage characteristics. The foliage may also show signs of disease or pests before the fruit does.
Tomatoes require regular fertilization and watering. The soil must be prepared well in advance of planting, which can take up time and energy. In addition, the leaves and vines are hosts for various pests and must be vigilantly monitored for signs of infestation. Because there are so many varieties of tomato, it is important to get good advice from an experienced gardener or nursery operator when you first begin. Also, it is best to keep records of the types that do well in your garden, as their names and grow instructions become invaluable over time.
UTMOST CAUTION: These plants are hosts to a fungus known as “fusarium wilt,” caused by the fungus fusarium oxysporum. This fungus attacks the plants vascular system and stops the movement of water and nutrients. The plant literally dies of starvation and wilt because the fungus actually blocks the movement of water and nutrients within the plant. This can happen very quickly or very slowly, over a period of weeks or months, depending on the variety and strain of fusarium.
The most common sign that your plant is infected is wilting, even if only in extreme heat. Another sign is sudden stunting of growth for no apparent reason. The roots of infected plants often turn a dark color and the outer skin of the fruit is a brownish-grey color.
There is no chemical cure for fusarium wilt. If your entire garden becomes infected, you must discard all of your plants and begin again with new seeds or plants. Your tools should be soaked in a 10% chlorine bleach solution and your soil should be replaced with new, sterile soil. NEVER use soil from an infected bed in an uninfected one.
If you believe your plants are infected, you should immediately pull them out of the ground, wrap them in plastic and throw them in the trash. NEVER add infected plants to your compost pile as the fusarium fungus can survive in the soil for years if no plant is present.
You should also keep a close eye on your other plants because they may show signs of wilting even though they seem healthy. Wilting in the daytime is often a sign of fusarium infection.
Finally, NEVER purchase tomato plants from untrusted sources because the fusarium fungus can easily be transmitted from one garden to another. ALWAYS use sterilized gardening tools and make sure not to touch any other part of the plant than the fruit or stem.
Good luck with your tomato growing and remember, happy plants make good fruit!
Tomatoes are a favorite for the back-yard gardener. They thrive when other plants may fail and they can provide you with a bountiful crop of healthy, delicious food. Tomatoes appear to have been cultivated in South America for 8000 years. Today there are more than 500 varieties of tomatoes grown throughout North America. They are members of the Nightshade family and their fruit is considered a berry.
The tomato plant can grow to a height of 3 feet and can be prone to disease, so give them support with a stake or cage. They should be planted about 2 feet apart.
You can start your plants from seeds or buy starter plants. They need 6-8 hours of full sun each day and well drained, fertile soil. Water the plants when the soil is dry to the touch. Pinch out the top when the plant is young to encourage bushy growth.
Green and orange varieties are generally more acid and better for canning. Yellow and purple varieties are sweeter.
When the plant flowers, you will need to hand pollinate by using a Q-tip or brush to transfer pollen from the stamen to the stigma of each flower. This could take all summer. Once the fruit starts to form, stop watering the foliage and keep it free of insects which may harm the fruit. Pick when it is full size but still green. A ripe tomato has a mild taste and gives slightly when pressed.
Use the largest, healthiest fruits for fresh eating or processing (canning, freezing, sauces). Smaller fruits not suitable for fresh use can be canned whole, made into paste or juice.
Always remove the calyx or stem of the tomato before canning. Add bottled lemon juice or citric acid to jars (never vinegar which is an acid) before filling with tomatoes. This prevents spoiling. Process pints for 35 minutes, quarts for 40 minutes in a boiling water bath.
Freezing whole tomatoes: Wash gently, remove stem and blossom end, plunge into water and drain immediately. Pat dry; place on a paper towel until the bottom of the towel becomes damp. Freeze.
To use, remove from freezer and let stand until frozen soft (about 2 hours). Place frozen tomato in a bowl and break apart.
Tomato paste: To make your own, cut tomatoes in half and place skin side up on a baking sheet. Broil 3-5 minutes, until skin begins to darken. Place in a bowl and cover with a lid or plate; let stand for about 30 minutes. Remove the skin and chop. Place in freezer bag(s) and return to freezer.
This type of paste is great for cooking and has a fresh-picked quality. It also can be used instead of canned tomatoes in soups and stews.
Tomato juice: To make your own,
Cut firm, ripe tomatoes in half and squeeze the seeds and juice through a sieve or potato ricer into a large bowl. Discard the seeds. Add 1½ teaspoons salt to each quart juice and stir well. For every quart of juice add 1 cup of cold water. (Add no more than 4 cups water to each gallon of juice.) Stir well again.
Pour into jars or containers, cover, and store in refrigerator until ready to serve. Tomato juice will keep for about 3 days. Makes 2 quarts.
Sautéed bell peppers: Cut a medium-sized red bell pepper into strips; remove the seeds and white membrane. In a skillet, heat 2 tablespoons of butter or bacon grease. Add the bell pepper strips and the seeds from 1 large poblano pepper (or substitute half a green or red bell pepper for the poblano pepper). Sauté until they are tender.
Sautéed red bell peppers: Cut out the stem and hollow part surrounding it, then cut into narrow strips. In a skillet heat 2 tablespoons butter or bacon grease.
Sources & references used in this article:
Genetic dissection of Verticillium wilt resistance mediated by tomato Ve1 by EF Fradin, Z Zhang, JCJ Ayala… – Plant …, 2009 – Am Soc Plant Biol
Soil solarization for the control of tomato and eggplant Verticillium wilt and its effect on weed and micro-arthropod communities. by R Ghini, W Bettiol, CA Spadotto… – Embrapa Meio …, 1993 – alice.cnptia.embrapa.br
Low cost application of soil solarization in covered plastic houses for the control of Verticillium wilt of tomatoes in Greece by EC Tjamos, V Karapapa, D Bardas – III International Symposium on Soil …, 1988 – actahort.org
Verticillium wilt of tomatoes—the role of pectic and cellulolytic enzymes by RKS Wood – Annals of Applied Biology, 1961 – Wiley Online Library
Efficacy of methyl bromide alternatives for Verticillium and weed management in tomatoes by FJ Louws, LM Ferguson, K Ivors, J Driver… – North Carolina State …, 2004 – researchgate.net
PLANT GROWTH RESPONSES TO VESICULAR‐ARBUSCULAR MYCORRHIZA: XIV. INTERACTIONS WITH VERTICILLIUM WILT ON TOMATO PLANTS by E Bååth, DS Hayman – New Phytologist, 1983 – Wiley Online Library
Reduced symptoms of Verticillium wilt in transgenic tomato expressing a bacterial ACC deaminase by MM Robison, S Shah, B Tamot, KP Pauls… – Molecular Plant …, 2001 – Wiley Online Library
Vascular coating: a barrier to colonization by the pathogen in Verticillium wilt of tomato by J Robb, DA Powell, PFS Street – Canadian Journal of Botany, 1989 – NRC Research Press
A new aggressive strain of Verticillium albo-atrum in Verticillium resistant cultivars of tomato in the Netherlands by SJ Paternotte, HA Van Kesteren – Netherlands journal of plant pathology, 1993 – Springer