Phytophthora: Soil Disease Identification and Treatment

Phytophthora is a soil-borne fungal disease that can cause wide-spread problems. If vulnerable crops are monitored and treated effectively, Phytophthora can be controlled.

There are several different types of Phytophthora, including Cinnamomi, Ramorum, Infestans, Capsici and Palmivora. They are known to attack a wide range of crops including pumpkins, watermelons, beans, spinach, turnips and even olive trees.

Signs and Symptoms

Phytophthora Cinnamomi is the most common, destructive and widely distributed species of this disease, found in more than 70 countries. The pathogen generally spreads in areas where there is significant moisture and poor soil quality and drainage.

Phytophthora Cinnamomi destroys the structure of roots, causing rot and preventing plants from absorbing water and nutrients. Early symptoms include wilting, yellowing as well as darkening of root colour. If not caught quickly, infection often leads to the death of plants, especially in dry summer conditions.

Phytophthora Ramorum can cause “sudden death” in oak trees given the right moist conditions, turning foliage brown and marking bark with lesions in a few weeks. It can be identified by looking for symptoms on other known hosts in the area, such as rhododendrons and other trees. If signs are seen nearby, it is likely Phytophthora Ramorum is the culprit.

Phytophthora Infestans causes significant losses in potato crops around the world and appears as leaf rot or lesions and rotting, sunken brown and purple areas on both tubers and fruit.

Other variations of Phytophthora include Capsici, which materializes in the form of water-soaked foliar lesions and stem necrosis and Phytophthora Palmivora, a dark-staining canker. While Phytophthora Capsici is known to affect beans and peas, Palmivora has been witnessed in everything from olive trees to orchids.

Prevention and Treatment

It is essential to monitor crops regularly and treat them thoroughly if infection is suspected. As the pathogen is soil-based, an effective treatment is the application of an environmentally friendly product like TerraClean. TerraClean is biodegradable. It can be applied any time. It’s many uses include as a pre-plant dip, a soil drench, a surface disinfectant and a foliar spray. While it will eradicate forms of Phytophthora, it will also increase oxygenation at the roots and improve nutrient intake in plants.

With Phytophthora’s ability to attack many common crops and cause crippling losses, it is imperative to recognize the signs of the disease and treat it quickly.