Emergency use registration for halo blight (Diaporthe leaf spot/blight) on hops renewed for 2023

Melanie Filotas, Horticulture IPM Specialist – OMAFRA and Josh Mosiondz – Provincial Minor Use Coordinator, OMAFRA

The Pest Management Regulatory Agency (PMRA) recently announced the approval of an Emergency Use Registration (EUR) for FULLBACK® 125 SC Fungicide for control of halo blight (Diaporthe humulicola – sometimes referred to as Diaporthe leaf spot/blight) on hops in numerous provinces in Canada. This EUR for FULLBACK® 125 SC Fungicide on hops can be used only in Ontario, Quebec, Saskatchewan, Manitoba and Prince Edward Island from June 1, 2023, until May 31, 2024.

Halo blight is a new disease affecting hops in northeastern North America since 2017. Symptoms begin as brownish-grey, eliptical lessions on leaves that may have white margins. Severe disease can lead to leaf browning, reduced cone development, and cone browning and shattering. Significant losses from this disease have been reported from hopyards in Quebec and the northeastern US. Diaporthe leaf blight was first observed in an Ontario hop yard in June 2020, and has since been reported from multiple hop yards across the province.

FULLBACK® 125 SC Fungicide was already labeled for management of diseases on a wide range of crops in Canada. This use will also be addressed as a future label expansion by an Agriculture and Agri-Food Canada – Pest Management Centre (AAFC-PMC) submission through the regional upgrade selected by Quebec at the 2022 AAFC-PMC ‘A’ priority setting workshop (pending favourable trial results and subsequent submission evaluation by PMRA).  This EUR request was initiated by Quebec with support from the Ontario Hops Growers Association in response to significant yield losses and spread of halo blight in recent field seasons.

The following is provided as an abbreviated, general outline only. Users should be making disease management decisions within a robust integrated disease management program and should consult the complete emergency use label before using FULLBACK® 125 SC Fungicide.

Crop(s)TargetRate (mL product/ha)Application InformationPre-Harvest Interval – PHI (Days)
Hops  Control Halo Blight (Diaporthe humulicola)731 – 1024Apply in sufficient water volume to provide uniform coverage, when conditions are favourable for disease development. Do not apply more than 2048 mL per hectare/season (maximum 2 applications) and do not exceed 1024 mL/ha in a single application. Disease control will be reduced if rain occurs with 2 hours of application. 12 hour restricted entry interval.17

Toxic to aquatic organisms and non-target terrestrial plants. Observe spray buffer zones specified under DIRECTIONS FOR USE. This product demonstrates the properties and characteristics associated with chemicals detected in ground water. The use of flutriafol in areas where soils are permeable, particularly where the water table is shallow, may result in ground water contamination. Flutriafol is persistent and may carry over. The label recommends that this product not be used in areas treated with any products containing flutriafol during the previous season. To reduce runoff from treated areas into aquatic habitats avoid application to areas with a moderate to steep slope, compacted soil, or clay. Avoid application when heavy rain is forecast. Contamination of aquatic areas as a result of runoff may be reduced by including a vegetative strip between the treated area and the edge of the water body.

Follow all other precautions, restrictions, and directions for use on the FULLBACK® 125 SC Fungicide.

For a copy of the emergency use label, visit the PMRA label site. Ontario growers may contact Melanie Filotas, Horticulture IPM Specialist, OMAFRA, Simcoe, melanie.filotas@ontario.ca,  or Josh Mosiondz, Provincial Minor Use Coordinator, OMAFRA, Guelph, joshua.mosiondz@ontario.ca. Non-Ontario growers from participating provinces may contact their local Provincial Minor Use Coordinator or provincial crop specialist(s).  Alternatively, you may contact your regional supply outlet or FMC of Canada Limited representatives.

Note:  This article is not intended to be an endorsement or recommendation for this particular product, but rather a notice of registration activity

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