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Minnesota Oats Variety Trials
By Deon Stuthman, Roger Caspers, Richard Halstead
Crown rust (Puccinia sp.) infections continue to be the major risk for oat production. This year we are dividing the rust reading into two columns: one headed with “Amount Infected” and the other
with “Reaction Type” (see Table 9).
The value in the amount column predicts the relative proportion of initial rust spores that achieve a successful infection. The reaction type value indicates the size of the pustule or alternatively how much the pustule is restricted by the host reaction. Either way, a small and/or restricted pustule produces fewer spores for re-infection that begins about 8-10 days after the initial infection. Depending upon the plant growth stage at initial infection, there can be 1 to 3 cycles of re-infection during an oat-growing season. The final amount of rust infection depends upon the number and size of spore-producing pustules that will produce the spores for the second and subsequent infections. It is these infections that really cause the damage.
Yield data for oats is presented in Tables 6 and 7. Agronomic data and disease responses are presented in Tables 8 and 9. For all 40 entries of the variety trial, yields in 2001 were highest at Morris (113
bu/A), and Waseca (103 bu/A), and lowest at Rosemount (67 bu/A).
Planting was delayed at most locations because of excess soil moisture. Planting began at Waseca on April 19 and finished at Stephen on May 31. Dry weather and extremely high temperatures during the last half of June and much of July negatively impacted some varieties. In 2001, ‘Vista’ from the University of Wisconsin was again the highest yielding cultivar, followed by ‘AC Assiniboa’ from Agriculture & Food Canada in Manitoba and ‘Richard’ from the University of Minnesota.
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