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 erythroseptica
Chemical control can be difficult due to resistance development to some fungicides. Also there are few fungicidal modes of action that are effective. This includes the formerly successful metalaxyl, which is now widely ineffective due to resistance exhibited in the pathogen. Mefenoxam is another fungicide that pink rot pathogens have shown resistance against. However, research has shown that a combination of mefenoxam and oxathiapiprolin has demonstrated effectiveness on suppressing pink rot. There have been studies done on phosphorous acid (Phostrol) as a systemic and contact fungicide against pink rot, but the exact mode of action has not yet been determined. Fluopicolide, part of the benzamide class of fungicides, has been shown to be effective at reducing pink rot on field scales. There has not yet been cross-resistance between fluopicolide and mefenoxam, meaning these fungicides can be used rotationally to minimize the development of resistance.