b'A NEW TOOL HELPING YOU IN THE REALM OF RETAIL SEED SALES.BACTERIAL LEAF STREAK: AN EMERGING THREATIts one of the newer and lesser-known diseases in Canada. We ask the experts about what can be done to guard cereal crops against this destructive pathogen.Marc ZienkiewiczAs a seed grower, what experience have youWhat have to come to learn about bacterial had with bacterial leaf streak? leaf streak since then?Last years growing season is a good placeBacterial leaf streak, or BLS, is present in to start. We saw many potential perilsgrowing areas around the world where which could have contributed to the issuemoisture and warm growing conditions Eric McLean including a long winter, delayed thaw, wetare plentiful, often under irrigation. Its not Seeds Canada spring soils and delayed seeding. A lot ofsomething that western Canadian varie-Vice-President/J.S. Henry crop residue was left to rot as the fall ofties are screened for during development & Son Owner 2019 was wet and harvest drew out, andas we can often be arid or definitely drier After a brief three years in thelittle field work was done. Things driedand cool enough for it not to be a prob-feed business, Eric began hisout well for some and the crop went inlem. It can cause damage at various stages career at JS Henry & Son.relatively flawless, but then we waited andof development as its polycyclic, which The business has grown fromwaited for moisture. Things were lookingmeans that infection can occur through-3,000 acres and processingdry by late June and many were worriedout the growing season starting from 150,000 bushels annually, toabout drought setting in. I personally wasoverwintering on host plants, infected a 6,500-acre stock seed farmon the edge of a significant rainfall eventseed/soil, wind-borne infection, which all that contracts around 20,000which occurred right at flag leaf timingcombined under the right conditions can acres and processes 750,000in the crop, and the moisture levels werelead to rapid development. There are no bushels annually. increased six to 10 times the norm withincompletely effective treatments out there. a 72-hour period, and humidity shot upSome seed treatments have shown some with average daily temperatures over andeffectiveness through time, but nothing is above 26 C for the following weeks.better than genetic resistance. This set the stage for bacterial leaf streak in one of our fields. When we sawHow do you advise growers to manage it?it, we mistakenly identified it as a fungalThe best way to manage the disease is to infection for which we sprayed fungicide,source clean seed from unaffected areas WHAT IS BACTERIALbut the wheat crop failed to grow out of itand grow varieties that have expressed LEAF STREAK? and many of our farmer customers startedresistance in trials. With no official ratings to call asking what was happening withgiven to Canadian varieties upon registra-Caused by thetheir wheat and what could be done. Ition, that latter part is difficult. Knowing pathogen Xanthomonasasked a few trusted advisors and research- this, the picture becomes clearer as to translucens, thisers what was happening, and uncertaintywhy bacterial leaf streak impacted so bacterium infects cerealgave way to helplessness as we knew thatmany acres of a popular variety, which crops around the world,we were in the infected area and camemade up to 30 per cent of our sales over and is beginning to rearto understand that we could do little tothe past few years. We had a very dry fall its head in Canada. salvage the situation.and winter moisture levels were quite low. Hopefully the disease cycle will be broken in 2021, or else significantly reduced. 40GERMINATION.CAJULY 2021'