ontario sugar beet growers - Atrium - University of Guelph

CROP: Sugar beet (Beta vulgaris L.) cv. E 17
PEST:
Cercospora leafspot, Cercospora beticola, Sacc.
NAME AND AGENCY:
PITBLADO, R E
Ridgetown College, University of Guelph, Ridgetown, Ontario, NOP 2C0
Tel: (5 19) 674-1605 Fax: (5 19) 674-1600 E-mail: rpitblad@ridgetownc.uoguelph.ca
TITLE:
CERCOSPORA LEAF SPOT CONTROL IN SUGARBEETS USING HIGH
RATES OF QUADRIS-2005
MATERIALS: QUADRIS 250EC (azoxystrobin), HEADLINE 250EC (pyraclostrobin), PREV AM
(experimental), CUPROFIX 40DF (TD 2389-01 36.9% basic copper sulfate)
METHODS: Sugar beets were planted at the research station in kdgetown on May 9,2005. Three row
plots were established, 7m in length with rows spaced 0.75m apart, replicated four times in a randomized
complete block design. The foliar applications were applied using a specialized small plot research CO,
sprayer with a three nozzled hand-held boom applying 200Lha of spray mixture. Two rows per treatment
were sprayed with one unsprayed row between plots. Spray applications were applied on July 12 and
August 10 following the weather timed fungicide spray program Beetcast. Foliar disease assessments
were made on September 1 by counting the number of leaf lesion sites and on September 13 by rating the
level of disease control between 0-10 with 0 indicating no control and the plants severely spotted while
10 indicated high levels of control with no leaf spots being noted. Results were analysed using the
Duncan's multiple range test (Ps 0.05).
RESULTS: Data are presented in Table 1.
CONCLUSIONS: QUADRIS 250EC used at the higher rate equal to HEADLINE 250EC provided
equal Cercospora Leafspot control in sugarbeets. 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
sugarbeets than the other fungicides.