b'What does BLS look like? Research suggests that the pathogen does On the leaves, the typical initial symp- not appear to survive in the soil itself for toms appear as small, water-soaked, linearlong periods of time. The pathogen can lesions running parallel to the leaf veins. Ifalso survive in the seed. Seed is the most humidity is really high, you might be ableimportant source of primary inoculum to see the bacterial ooze on the lesions,and is how the organism is introduced in Maria Constanza Fleitas which appears as little yellow milky drop- new areas. When the pathogen is there, Post-doctoral Fellow, Cereallets visible to the naked eye. and the weather is warm and moist, the and Flax Pathology Program Its often easy to misdiagnose thebacterium is going to multiply, it will be University of Saskatchewan problem because it usually doesnt occurreleased and splashed around and that is Maria is an agriculturein isolation. It usually occurs with otherhow it gets onto host plants that are grow-engineer who graduatedpathogens, like tan spot. However, some- ing in the spring. The organism penetrates from the National Universitything particular about this disease arethe plant through natural openings or of La Plata, Buenos Aires,the dark fruiting bodies that the septoriawounds that can be created by hail, wind, Argentina, where she alsocomplex pathogens form on the tan-brownor mechanical damage caused by insects, completed her PhD studiesdead tissue giving lesions a speckled/ for example. Once the pathogen infects, focusing on the tolerance todotted appearance.it will start to form on the leaves making foliar diseases of wheat.the typical water-soaked lesions that run So, what do we know about the pathogen thatparallel to the veins. If the weather is causes BLS?right, the bacteria will keep multiplying Xanthomonas translucens affects mostly(they can do it at remarkable speed) and small grain cereals like wheat, barley, ryethen, they will splash around and infect and triticale, but also might be presentmore leaves. in native grasses or forage grasses. Any grassy cultivated or wild species of grassHow can it best be managed?can be infected with the bacterium. WheatRight now, there are only a few things that is probably the most susceptible of ourcan be done about it. Watch and scout for cultivated cereals, but it depends on theBLS, learn how to recognize the disease pathovar of the bacterium that is present.(this is a new one for most people). Learn It likes areas with abundant moisture. Thiswhere you can get diagnostic support if is because bacteria do not do well in dryyoure suspicious that you have an issue conditions. Warm days and cool nightsand start as clean as you can. One addi-lead to dew formation playing a significanttional characteristic to look for is a lack of role in the infection because it helps thecontrol of plant symptoms with fungicides.bacterium penetrate through stomata orOne may feel they have a fungal leaf spot hydathodes which are natural openings(e.g. tan spot and/or the septoria complex) present in the leaf (not visible to the nakedproblem and spray a fungicide. If fungi-eye). Severe weather events that includecide performance is non-existent then you heavy rain, strong winds and hail can alsomay be dealing with BLS, but a laboratory create wounds that facilitate BLS infec- test of plant tissues will be needed to con-tion of the cereal plant. The bacteria canfirm the causal agent as the BLS pathogen. spread short distances through rain splashIf you have confirmed symptoms in a or wind-driven rain, but can travel longfield, producers may want to avoid using distances via infected seed, although shortgrain harvested from the affected field for distance dispersal primarily to adjacentseed in subsequent years.fields may occur via major thunderstorm systems. Here strong winds may pick upIs a test available?and spread infected crop debris. RainA test for BLS is on its way. One objective splashing of the bacterial ooze on infectedis to develop a seed testing protocol for leaves may disperse the bacteria in waterbarley seeds. This technology will have droplets that strong winds carry to adja- immediate application and will reduce cent fields. production risks for farmers. If we get the funding, we are also planning to extend How does the BLS pathogens life cycle work? this study for bread and durum wheat.The organism either overwinters in crop debris, perennial weeds, or native grasses. JULY 2021 GERMINATION.CA 41'