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| Department of Agriculture, Aquaculture and Fisheries |
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Abstract: The fungicides; azoxystrobin + propiconazole (Quilt), boscalid + pyraclostrobin (Pristine), chlorothalonil (Bravo 500),
phosphorous acid (Confine), prothioconazole (Proline) and pyraclostrobin (Cabrio) were applied to a lowbush blueberry sprout field on
June 25 (ave. sprout height 10 cm) using a pressurized back pack sprayer operating at 270 KPa and delivering 500 L/ha. The trial design
was a randomized complete block design with 4 replications and with each plot measuring 2 by 6 meters. Septoria leaf spot was assessed
on July 31 using a 1 to 5 disease severity rating scale. All treatments significantly reduced Septoria leaf spot compared to the untreated
control (P=0.05). Compared to the check, the percent disease reduction for the 10 treatments was; Cabrio 1.0 kg/ha - 16%, Quilt 0.5 L/ha - 23%,
Confine 10 L/ha - 23%, Confine 5 L/ha - 26%, Quilt 1.0 L/ha - 32%, Pristine 1.6 kg/ha - 32%, Bravo 2.4 L/ha - 42%, Bravo 5.2 L/ha - 45%, Bravo
7.2 L/ha - 48%, Proline 0.315 L/ha - 61%. No phytotoxicity was observed for any of the treatments. Increasing the rate of Bravo from 2.4 to 7.2 L/ha
did not significantly improve disease suppression indicating that the low rate is adequate for early season leaf spot control. A single application of
Proline 480 SC gave good disease suppression indicating that it should be an excellent disease management tool for lowbush blueberry production.