Cilantro Crisis: The Powdery Mildew Problem in Tennessee

Cilantro is a popular herb in many kitchens. It is also known as coriander. It is part of the Apiaceae family. This herb is grown in many U. S. states, including Tennessee. It is often grown in greenhouses. In early spring of 2025, a big problem hit two greenhouses in Eagleville, Tennessee. The issue was powdery mildew. This is a fungal disease. It shows up as a white, powdery growth on leaves and stems. Out of 250 cilantro plants checked, 78% were affected. The disease was quite severe, with a rating of 54% on a scale from 0 to 5. The fungus causing the trouble was identified as Erysiphe heraclei. This fungus is known to attack plants in the Apiaceae family. To confirm the identification, scientists looked at the fungus under a microscope. They also did some genetic testing. The results matched known samples of E. heraclei from other places, like Mexico and South Africa. This fungus has not been seen on cilantro in the United States before. This makes the situation in Tennessee quite unusual. Powdery mildew can spread quickly in greenhouses. This is because the environment is controlled. The temperature and humidity are just right for the fungus to grow. To stop the spread, preventive measures are needed. This could include better ventilation, using resistant plant varieties, or applying fungicides. Farmers and scientists need to work together. They must find the best ways to protect cilantro crops. This is important for the future of cilantro farming in the United States. The discovery of E. heraclei on cilantro in Tennessee is a wake-up call. It shows that new diseases can pop up anytime. Farmers need to stay alert. They should watch for signs of disease and act quickly if they see any. This way, they can protect their crops and ensure a steady supply of cilantro for everyone to enjoy. It is also important to note that powdery mildew is not just a problem for cilantro. It can affect many other plants too. This makes it a widespread issue in agriculture.