Late Blight: A Devastating Tomato Disease
Late blight is a serious fungal disease that affects both tomatoes and potatoes. It is the most destructive of the blights that affect these crops and can cause significant losses in yield.
History and Impact of Late Blight
Late blight was responsible for the Irish Potato Famine in the 1850s, when millions of people starved due to the devastation caused by the disease. On tomatoes, late blight can destroy an entire crop within days if conditions are favorable.
Symptoms of Late Blight on Tomatoes
The pathogen that causes late blight, Phytophthora infestans, needs moisture to survive. It produces spores that can travel through the air for several miles. When these spores land on a tomato plant, they can germinate and infect the plant within hours.
The first symptom of late blight on tomatoes is the appearance of small, water-soaked lesions on the leaves, stems, or fruit. These lesions will gradually enlarge and turn gray-green or yellow. As the disease progresses, the lesions will produce spores that can spread the disease to other plants.
Preventing Late Blight on Tomatoes
Sanitation is the first step in preventing late blight. Clean up all fallen fruit and debris from the garden area. This is especially important in warmer climates where the disease may overwinter in fallen fruit.
There are no tomato varieties that are completely resistant to late blight. However, some varieties are more resistant than others. Inspect your plants regularly for signs of the disease, especially during wet weather.
Fungicides can also be used to prevent late blight. Repeated applications are necessary throughout the growing season, as the disease can strike at any time. For organic gardeners, there are some fixed copper products that are approved for use.
Treating Late Blight on Tomatoes
If you find late blight on your tomato plants, it is important to act quickly. Remove and destroy all infected plants immediately. This will help to prevent the disease from spreading to other plants.
There are no effective treatments for late blight once it has infected a plant. However, fungicides can be used to protect healthy plants from infection.
Conclusion
Late blight is a serious disease that can devastate tomato crops. However, by taking steps to prevent and control the disease, you can help to protect your plants and ensure a successful harvest.
