field setting, it is not impossible, and laboratory and greenhouse trials are showing bacteriophages to potentially be a very effective control mechanism. however, there are a few obstacles to surmount before field trials can begin. a large problem is that they are damaged by uv light, so applying the phage mixture during the evening will help promote its viability. also, providing the phages with susceptible non-pathogenic bacteria to replicate with can ensure there is adequate persistence until the bacteriophages can spread to the targeted bacteria. the bacteriophages are unable to kill all the bacteria, because they need a dense population of bacteria in order to effectively infect and spread, so while the phages were able to decrease the number of diseased plants by up to 35%, around 2,000 colony forming units per milliliter (an estimate of living bacteria cells) were able to survive the treatment. lastly, the use of these bacteriophages places strong selection on the host bacteria, which causes a high probability of developing resistance to the attacking bacteriophage. thus it is recommended that multiple strains of the bacteriophage be used in each application so the bacteria do not have a chance to develop resistance to any one strain. importance the disease was first identified in the western states of, california, washington, texas, arizona and idaho in the 1970s and initially led to substantial yield losses in those areas. erwinia caratovara subsp betavascularum was not discovered in montana until 1998. when it first appeared, beet vascular necrosis caused individual farm yield loss ranging from 5–70% in montana's bighorn valley. today, yield losses from the disease are generally infrequent and patchy as most producers plant resistant varieties. infection rate is generally low if resistant cultivars are chosen; however, warmer and wetter conditions can lead to higher than normal instance of disease if infection does occur, bacterial root rots can not only cause economic losses in the field, but also can in storage and processing as well. in processing plants, rotten roots complicate slicing and the bacterially-produced slime can clog filters. this is especially problematic with late-infected beets which are generally harvested and processed along with healthy beets. the disease can also lower sugar-content which greatly reduces the quality