Sep 16, 2021 · Lettuce that is exposed to long periods of cool, wet temperatures is highly susceptible to this fungus-like infection. Symptoms of this disease include yellow or brown spots on leaves; wilting; and the development of fluffy mold, typically on the underside of leaves.

On lettuce, the type of damage caused by these fungi has two phases, depending on when it starts. The first is the damping-off phase. It attacks the seedlings. The second is the field phase. It causes a watery, soft rot of the lower leaves and crown (Photo 1, above, left).

In this article, we will address prevention, identification, and control strategies for fungal diseases in lettuce, providing technical, nutritional, and practical advice for producers and specialists.

Jul 20, 2022 · Fungal lettuce diseases, such as damping off or sclerotinia drop (white mold), are caused by soil borne fungi that thrive in cool, damp soil and are primarily lettuce seedling diseases. Treat these lettuce diseases by spacing the plants apart to provide airflow, and by reducing the amount of irrigation the seedlings receive.

Jul 16, 2023 · One of the most prevalent diseases in lettuce plants is downy mildew. It is caused by a fungus called Bremia lactucae and thrives in cool, wet conditions. The first signs of downy mildew are the appearance of yellow or pale green patches on the upper leaf surface.

Downy Mildew (fungus – Bremia lactucae): First symptoms are yellowish or light green areas on the upper surface of the leaves. As the lesions enlarge, the fungus produces downy growth on the underside of the leaf . The affected tissue turns brown, …

Fusarium wilt of lettuce is caused by the soil-borne fungus Fusarium oxysporum f. sp. lactucae. This article decribes the nature of the disease and it's development. It also gives suggestions for how to manage it.

Powdery mildew is a well-known fungal disease that affects almost all crops. It usually grows on the upper and lower sides of the leaves, and the outer leaves are covered in white mycelium and have a powdery appearance. This fungus can appear in any vegetative state of a lettuce crop.

Dec 7, 2023 · Lettuce mosaic, lettuce big-vein, impatiens necrotic spot, and tomato spotted wilt are all important viral diseases of lettuce, while the ubiquitous root-knot nematode is the most prominent nematode pest.

Lettuce crops can be attacked by several fungal and Oomycete diseases, the principal ones being downy mildew, grey mould and sclerotinia. Other diseases can be very damaging in certain cropping situations, either regularly or occasionally, such as ring spot, powdery mildew and pythium root rot.