ontario sugar beet growers - Atrium - University of Guelph

CROP: Sugar beet (Beta vulgaris L.) cv. El 7
PEST:
Rhizoctonia Crown Rot, Rhizoctonia solani Kuhn
NAME AND AGENCY:
PITBLADO, R E
Ridgetown College, University of Guelph, Ridgetown, Ontario, NOP 2C0
Tel: (5 19) 674-1 605 Fax: (5 19) 674-1 600 E-mail: rpitblad@ridgetownc.uoguelph.ca
TITLE:
EVALUATION OF HEADS UP FOR THE CONTROL OF RHIZOCTONIA
CROWN ROT IN SUGARBEETS - 2005
MATERIALS: HEADS UP (disease regulator experimental product), HEADLINE 250EC
(pyraclostrobin)
METHODS: Sugarbeet seeds were spray misted with a lg/L concentration of HEADS UP to the point of
wetness (1 6ml onto 10 g of seed) and mixed thoroughly and allowed to air dry - treatment #l. In
treatment #2 the sugarbeet seeds were submerged for 5 minutes in a 1 g/L solution of HEADS UP to
allow more of the chemical to move into the seed and then was allowed to air dry. Sugarbeet seeds were
planted at the research station in Ridgetown, on May 6,2005. Plots were two rows, 7 m in length spaced
0.75 cm apart, replicated four times in a randomized complete block design. The in-furrow spray
applications were directed over the seed and then covered on May 6 using a specialized small plot
research CO, sprayer with a single nozzled hand-held boom applying 200L/ha of spray mixture. The at
emergence spray was applied over the planted row in a 15 cm band on May 26. The Rhizoctonia crown
rot organism was grown out onto wheat seeds and sprinkled along the length of each row to encourage a
level of disease pressure. Assessments were conducted by counting the number of emerged plants on
June 2, a plant vigour rating on July 15 and a total plant count on July 28. Results were analysed using
the Duncan's multiple range test (P< 0.05).
RESULTS: Data are presented in Table 1.
CONCLUSIONS: The in-furrow sprays of both HEADS UP and HEADLINE 250EC significantly
allowed more seedlings to emerge, especially were HEADLINE l5OEC was used. This may have been
due to some growth promotant characteristic of these products or more realistically due to the manner in
which the ground was disturbed, loosened for the in-furrow application that then allowed for faster
sugarebeet emergence. This same rational may be used to explain the improved plant vigour ratings with
both of these treatments showing greater plant growth than the other treatments that were held back.
HEADS UP when applied as a seed treatment or when sprayed at time of emergence did not reduce or
control Rhizoctonia crown rot in sugarbeets. The in-furrow treatments were much more effective in
promoting healthy plants and increased plant stands. This could have been a combination of effective
Rhizoctonia Crown Rot fungicides andlor the differences in soil compaction around the seed at time of
planting.