Tomatillo diseases can pose significant challenges to growers, but with proper identification and management strategies, it's possible to mitigate their impact. Regular monitoring of plants, maintaining good cultural practices, and implementing preventive measures are crucial for keeping tomatillos healthy and productive. Additionally, selecting disease-resistant varieties can help reduce the risk of infection and ensure a successful harvest of these beloved fruits. By staying vigilant and proactive, growers can enjoy bountiful yields of flavorful tomatillos year after year.

Tomatillos (Physalis philadelphica), also known as Mexican husk tomatoes, are cherished for their tangy flavor and versatility in various culinary dishes, particularly in Latin American cuisine. However, like any cultivated plant, tomatillos are susceptible to diseases that can affect their growth and productivity. Understanding these common diseases, their symptoms, and how to manage them is crucial for cultivating healthy tomatillo plants. In this article, we'll explore some of the most prevalent diseases that afflict tomatillos, along with strategies for prevention and management.

1. Early Blight (Alternaria solani):

Early blight is a fungal disease caused by Alternaria solani. It typically appears as dark brown to black spots on the lower leaves of tomatillo plants. These spots may also have concentric rings, giving them a target-like appearance. If left unchecked, early blight can cause defoliation and reduce fruit yield.

Management: To manage early blight, remove infected leaves as soon as symptoms appear. Ensure proper spacing between plants to promote air circulation and reduce humidity. Mulching can also help prevent fungal spores from splashing onto the leaves. Fungicidal sprays containing copper or sulfur may be used as a preventive measure.

2. Late Blight (Phytophthora infestans):

Late blight is a notorious disease that affects tomatillos as well as tomatoes and potatoes. It is caused by the oomycete pathogen Phytophthora infestans. Symptoms include dark, water-soaked lesions on leaves and stems, which eventually turn brown and necrotic. In humid conditions, a white, fuzzy growth may appear on the underside of infected leaves.

Management: Prevention is key to managing late blight. Choose disease-resistant varieties when possible and avoid overhead watering, as moisture promotes the spread of the pathogen. Remove and destroy infected plant debris to prevent overwintering of the pathogen. Fungicides containing chlorothalonil or copper can help protect healthy plants from infection.

3. Powdery Mildew (Erysiphe spp. and Sphaerotheca spp.):

Powdery mildew is a common fungal disease that affects a wide range of plants, including tomatillos. It appears as a white, powdery growth on the leaves, stems, and fruits of affected plants. As the disease progresses, leaves may become distorted, turn yellow, and eventually die off.

Management: To prevent powdery mildew, plant tomatillos in areas with good air circulation and avoid overcrowding. Prune overcrowded foliage to improve ventilation and reduce humidity around the plants. Fungicidal sprays containing sulfur or potassium bicarbonate can help control powdery mildew outbreaks.

4. Tomato Yellow Leaf Curl Virus (TYLCV):

TYLCV is a viral disease transmitted by whiteflies (Bemisia tabaci). Infected tomatillo plants exhibit symptoms such as yellowing and curling of leaves, stunted growth, and reduced fruit production. The virus can spread rapidly, especially in warm climates.

Management: Control whitefly populations with insecticidal soaps or oils. Reflective mulches may also deter whiteflies from landing on plants. Remove and destroy infected plants to prevent the spread of the virus to healthy ones. Planting resistant varieties can provide some level of protection against TYLCV.

5. Bacterial Spot (Xanthomonas spp.):

Bacterial spot is a bacterial disease that affects tomatillos, peppers, and tomatoes. Symptoms include dark, water-soaked lesions on leaves, stems, and fruits. In severe cases, infected fruits may develop sunken lesions, rendering them unmarketable.

Management: Practice crop rotation to reduce the buildup of bacterial pathogens in the soil. Avoid overhead irrigation to minimize the spread of bacteria from plant to plant. Copper-based fungicides can help suppress bacterial spot outbreaks, but they must be applied preventatively and may not provide complete control.