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.
Phytophthora cactorum
The best way to manage "P. cactorum" is by implementing an integrated management plan. The combination of soil fumigation and proper cultural controls will be the best option for plant health. Recommended chemical controls products include fosetyl-Al, metalaxyl, and etridiazole. Prevention and sanitation are crucial because this pathogen is usually transmitted through cuts or injuries on the plant. The spores are easily transported through irrigation water and will splash to nearby plants. Elevating your plants above the ground can help to prevent infection. The pathogen thrives in moist soils therefore it is important to avoid very saturated soils as much as possible and one should work to prepare their soil for adequate drainage during the wet periods. Soil drainage and low soil pH may help to reduce the disease. Fertilizer regimen methods have been used to control against "P. cactorum". These fertilizers include organic materials that release ammonia, nitrous acid, and amendments to reduce the pH to less than 4. The use of raised beds and a carefully managed drip irrigation system will be important cultural practices that can be implemented. There are some form of biological controls that have been found to be somewhat successful with "Enterobacter aerogenes" and "Trichoderma".