Phytophthora cryptogea

Phytophthora cryptogea

Phytophthora cryptogea on a plant

Phytophthora cryptogea is a plant pathogen belonging to the genus Phytophthora. It is known to cause root and crown rot in a variety of host plants, leading to significant agricultural losses. This organism is part of the Oomycota group, which are often referred to as water molds.

Description

Phytophthora cryptogea is characterized by its ability to produce sporangia, which are asexual spores that can spread in water. The sporangia are typically lemon-shaped and can release zoospores that swim through water to infect new plants. This pathogen thrives in moist environments, making it particularly problematic in areas with poor drainage or excessive irrigation.

Host Range

This pathogen affects a wide range of host plants, including ornamental plants, vegetables, and field crops. Some of the most commonly affected plants include tomatoes, peppers, and ornamental flowers such as geraniums and petunias.

Symptoms

Infected plants often exhibit symptoms such as wilting, yellowing of leaves, and stunted growth. The most distinctive symptom is the development of a dark, water-soaked lesion at the base of the stem, which can lead to plant collapse. Root rot is also common, with roots appearing brown and mushy.

Disease Cycle

The life cycle of Phytophthora cryptogea involves both sexual and asexual reproduction. In the asexual phase, sporangia release zoospores that swim to new hosts. In the sexual phase, the pathogen forms oospores, which are thick-walled spores that can survive in soil for extended periods, allowing the pathogen to persist between growing seasons.

Management

Managing Phytophthora cryptogea involves a combination of cultural practices and chemical controls. Improving soil drainage and avoiding over-irrigation can reduce the risk of infection. Fungicides may be used to protect plants, but they are most effective when combined with other management strategies. Resistant plant varieties are also being developed to help reduce the impact of this pathogen.

Related Pages

• Phytophthora
• Plant pathology
• Oomycota
• Root rot