ontario sugar beet growers - Atrium - University of Guelph

spray treatments. This trial demonstrated that the time of infection plays a large role in the results obtained
using these fungicide treatments. Both QUADRIS 250EC and HEADLINE 250SC were effective in
controlling Rhizoctonia crown rot when applied when infection occurs. Effectiveness of either of these two
very effective fungicides is dependent on when infection occurs.
TITLE:
CONTROL OF RFIJZOCTONIA CROWN ROT IN SUGARBEETS- NON-
ARTIFICIALLY INOCULATED PLOT- 2005
CONCLUSIONS: The vigour ratings improved for the non in-furrow treated plots in this trial where the
plots did not have any additional Rhizoctonia crown rot disease inoculum to deal with compared to Trial 2
which contained a similar treatment list but had been artificially inoculated. The question was then was
whether or not the lack of vigour and seedling emergence in that trial was due to the method of applyng
the chemicals as an in-furrow treatment. It appears that in this trial the technique of applying the in-furrow
treatments did not give any advantage to emergence or plant vigour and thus one should conclude that in
trial 2 the benefits shown in the in-furrow treatments was due to its ability to control Rhizoctonia crown rot
infections at this early stage.
In this trial there was very little disease pressure with few plants dying as a result of infections by
Rhizoctonia. It should also be noted that the treatments for the control of Rhizoctonia crown rot did not
persist long enough to affect the leafspot disease caused by Cercospora.
TITLE:
CERCOSPORA LEAF SPOT CONTROL IN SUGARBEETS USING HIGH
RATES OF QUADRIS-2005
CONCLUSIONS: QUADRIS 250EC used at the higher rate equal to HEADLINE 250EC provided equal
Cercospora Leafspot control in sugar beets. The standard lower rate of QUADRIS 250EC performed
equally well however numerically there were more leafspot disease counted and it was not rated as high as
either the high rate of QUADRIS 250EC nor the lower commercial rate of HEADLINE 250EC.
CUPROFIX ULTRA 40DF effectively controlled Cercospora leafspot with similar levels of control than
both QUADRIS 250EC and HEADLINE 250EC. PRE AM was more effective than the untreated control
however it was considerably less effective in controlling Cercospora Leafspot in sugar beets than the otner
fungicides.
TITLE:
EVALUATION OF BEETCAST IN MICHIGAN FOR THE CONTROL OF
CERCOSPORA LEAFSPOT IN SUGARBEETS - 2005
CONCLUSIONS: Beetcast, the weather timed fungicide spray model, was the most effective advisory
tool to time fungicides for the control of c&cospora leafspot in sugar beets when compared to field
scouting and the advisory service provided by MAW. In the susceptible sugar beet variety BETA 545 1,
effective disease control was obtained using a 55135,55155 or a 70135 spray program which resulted in
lowering both the incidence of Cercospora disease but also increased sugar beet yields. The 70170
application schedule was the next most effective spray program while the Scouting and MAWN delivered
advisory service where the poorest resulting in lower sugar beet yields. In the more resistant sugar beet
cultivar HM 7 172 Rz the exact same pattern was observed that properly timed fungicides using an
effective weather model increased the level of disease control and improves sugar beet yields. The scouting
program apparently was not able to detect the need to apply the second spray on time as the delay resulted
in poor disease control and loss in sugar beet yeld. Similarly but even worst was the advisory service
timed through MAWN. The MAWN treatment resulted in the poorest fungicide spray program missing
both the initial spray, which was applied too late, along with missing all of the subsequent spray
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