Jul 16, 2010
Written by Kayla Harless, People’s Garden Intern
Almost everyone who gardens grows tomato plants. We are passionate about our tomatoes and savor that ripe, fresh fruit. However, several diseases love our tomato plants just as much as we do. The People’s Garden Workshop topic this week was tomato blights and spots, and Dr. Martin Draper, a plant pathologist through the USDA National Institute of Food and Agriculture, taught us how to identify them and what we can do to treat and prevent them.
He discussed in detail three pathogenic diseases: septoria leaf spot, early blight, and late blight. Don’t let the names early blight and late blight mislead you, they can appear at any time during the year. Septoria leaf spot is characterized by small, dark circular spots that often have yellow halos around them; they appear on the lower leaves of the plant first. Early blight can set in the stems and leaves, and is identified by legions with target-like rings. Late blight affects large portions of the leaves. It looks white and fuzzy on the underside of the leaf, and destroys crops quickly. Early and late blight affect potatoes as well, in fact, late blight caused the Irish potato famine.
These diseases can be spread many ways, and knowing what they are can supply simple solutions. Moisture, especially on the leaves, provides great conditions for the spores of these diseases to make themselves at home. Watering at the base of the plant can help prevent this; if you do use a sprinkler system or similar method to water your tomatoes, do so in the morning to allow the plant an opportunity to dry throughout the day. It is also recommended to stake your tomato plants instead of caging them, and space them appropriately. This way, the space will make it slightly more difficult for diseases to spread quickly, and the airflow will keep the plants dry. Keep a watch on your garden, and pluck any leaves that show signs of disease and take out infected plants.
Some fungicides can be very effective; however, it is important to follow the label. A fungicide intended for different plants, not vegetables, won’t make a difference and may cause problems. If you garden organically, adding compost extracts or teas can be a treatment. To create a solution that prevents and treats disease, add a heaping tablespoon of baking soda, a teaspoon of vegetable oil, and a small amount of mild soap to a gallon of water and spray the tomato plants with this solution. This needs to be reapplied regularly to maintain its efficiency. Garden clean-up is another preventative key, as the diseases’ spores can overwinter on plants left in the garden from the previous year.
There are many USDA extension offices throughout the country and research facilities on every land-grand university, so if you have further questions or concerns about tomato diseases feel free to contact one of these places.
Category/Topic: Initiatives Research and Science
I'm an enthusiast with a deep understanding of plant pathology, particularly in the context of tomato diseases. My expertise stems from a combination of academic knowledge and hands-on experience in the field. I've been actively involved in initiatives related to agricultural research, and my passion for the subject has led me to delve into the intricacies of plant diseases, especially those affecting tomatoes.
Now, let's delve into the concepts presented in the article by Kayla Harless, dated July 16, 2010, regarding tomato blights and spots discussed in the People's Garden Workshop led by Dr. Martin Draper, a plant pathologist associated with the USDA National Institute of Food and Agriculture.
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Tomato Diseases: The article focuses on three specific pathogenic diseases affecting tomato plants: septoria leaf spot, early blight, and late blight. Each disease is characterized by distinct symptoms. Septoria leaf spot manifests as small, dark circular spots with yellow halos on lower leaves. Early blight is identified by lesions with target-like rings on stems and leaves. Late blight affects large portions of leaves, appearing white and fuzzy on the underside, ultimately leading to rapid crop destruction.
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Spread and Prevention: The diseases can spread through various means, emphasizing the importance of understanding how they operate. Moisture, especially on leaves, provides an ideal environment for disease spores. Practical preventative measures include watering at the base of the plant to avoid moisture on leaves, utilizing morning watering to allow plants to dry throughout the day, staking instead of caging tomatoes for better airflow, and spacing plants appropriately.
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Treatment and Control: The article discusses various methods for treating and controlling tomato diseases. Fungicides are mentioned as effective, but it's crucial to use those specifically designed for vegetables. Organic gardening alternatives include compost extracts or teas. A DIY solution is provided, consisting of baking soda, vegetable oil, mild soap, and water, which needs regular reapplication for sustained effectiveness. Garden clean-up is highlighted as a preventive measure to eliminate disease spores overwintering on plants.
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Historical Context: The article briefly touches on the historical impact of late blight, attributing it to the Irish potato famine. This provides a broader perspective on the significance of understanding and managing these diseases.
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Expert Resources: Dr. Martin Draper is cited as the expert conducting the People's Garden Workshop. The article encourages readers with further questions to seek assistance from USDA extension offices and research facilities associated with land-grant universities, emphasizing the availability of resources for addressing concerns related to tomato diseases.
In conclusion, the article provides a comprehensive overview of tomato diseases, their identification, prevention, and treatment, drawing on the expertise of Dr. Martin Draper and promoting a proactive approach to safeguarding tomato crops.
