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P a g e 5South Area Field Day RecapLate Blight and StorageWe are now entering into one of the last stages of our cropyear. Although everyone is looking forward to a good harvest,we must remember that the next six weeks are probably themost critical in regards to the outcome of your hard work anddiligence throughout the growing season.Following breakfast, a tour of the PGA & McCain Potato PlotsJeff Bronsch from Sunrise Ag along with Chris Perry gave apresentation during breakfast on Variable Rate Irrigation. SteveMyshak of Isis Geomatics then gave a demonstration of how thistechnology works at a Perry Produce field. This small helicopterprovides images of the field to indicate low spots and areasneeding more nutrients. This information is then shared with theirrigation computer program which adjusts to provide an overallbalanced delivery system of moisture and nutrients. The imagesof the crowd below were taken by the device shown above.The event ended with a BBQ & French Fry lunchat the PGA shop. Thank you to all who attended!We hope to see more of you next year!Unfortunately we were faced with the “perfect storm” when itcame to Late Blight this year. Our aggressive monitoring systemand your persistent fungicide programs were able to containthe acres for the most part. Some of you have eliminated theworst acres; others have been top killing their vines. In the end,there were very few acres that succumbed to the pathogen.Both practices have been very beneficial but a diligentmonitoring of the tubers going into storage is now required.Spores from the infected plants can be washed off from therain or irrigation and infect the soil. This, in turn, can infect thetubers below ground. Tubers can also become infected duringharvest if they come into contact with an infected plant.Late Blight infection of tubers is characterized by irregularlyshaped, slightly depressed brown to purplish areas on the skin.These symptoms may be less obvious on russet and redskinnedcultivars. A tan to reddish brown, dry, granular rot isfound under the skin in the discolored area, extending into thetuber usually less than 1/2 inch (Fig. 6). The extent of rottingin a tuber depends on the susceptibility of the cultivar,temperature and length of time after the initial infection. Themargin of diseased tissue is not distinct and is marked bybrown finger-like extensions into the healthy tissue of the tuber.In time, the entire tuber becomes blighted and discolored. LateBlight rot of tubers is often accompanied by soft rot.If you suspect a problem with your stored tubers, send asample into Dr. Kawchuk in Lethbridge for testing. If time is ofthe essence, then give me a call and I can deliver yoursamples for you. I plan on making my rounds to visiteveryone during harvest this fall.Terence Hochstein - PGA Technical DirectorPotato Growers of Alberta6008 46 AvenueTaber, AB T1G 2B1Phone: 403-223-2262Fax: 403-223-2268E-mail:pga@albertapotatoes.caThe PGA assumes no responsibility for any errors in the information provided, nor assumes any liability forany damages incurred as a consequence, directly or indirectly, of the use and application of any of thecontents of The Potato Minute. Unless otherwise noted on an individual document, the PGA grants userspermission to reproduce and distribute information in the Potato Minute as long as the contents remainunaltered and as long as it is noted that the contents have been made available by the PGA.