Phytophthora ramorum
Detection of "P. ramorum" in watercourses has emerged as the earliest of early detection methods. This technique employs pear or rhododendron baits suspended in the watercourse using ropes, buckets, mesh bags, or other similar devices. If plants in the watershed are infected with "P. ramorum", zoospores of the pathogen (as well as other "Phytophthora" spp.) are likely present in adjacent waterways. Under conducive weather conditions, the zoospores are attracted to the baits and infect them, causing lesions that can be isolated to culture the pathogen or analyzed via PCR assay. This method has detected "P. ramorum" at scales ranging from small, intermittent seasonal drainages to the Garcia, Chetco, and South Fork Eel Rivers in California and Oregon (144, 352, and 689 mi2 drainage areas, respectively). It can detect the existence of infected plants in watersheds before any mortality from the infections becomes evident. Of course, it cannot detect the exact locations of those infected plants: at the first sign of "P. ramorum" propagules in the stream, crews must scour the watershed using all available means to find symptomatic vegetation.
Pythium dissotocum
As a root rot, it tends to have more severe effects on young plants and seedlings, where it can damage and kill newly forming roots necessary for plant growth and nutrient acquisition. As a result, many control methods involve limiting the amount of exposure early in the season. Effective measure include application of fungicides like mefenoxam and phosphonates, often in conjunction. Additionally, inoculation with "Pseudomonas chlororaphis," a common biocontrol inoculant used in horticulture, has potential to suppress symptoms of "P. dissotocum" infection, but is currently inconsistent in current trials, and doesn't block colonization. Like most root rots, "P. dissotocum" thrives in wet conditions. Preventing over-watering will help reduce infection in soil. Engaging in sanitation or fungicide treatment of tools and water can help reduce transmission and infection of "P. dissotocum" especially in irrigation or hydroponic systems. If infection has occurred, recovery can sometimes occur by trimming off damaged roots, and sterilizing those that are still white and healthy.