Reason 500 SC Fungicide for Control of Blue Mold of Tobacco

Reason® 500 SC Fungicide has been granted registration for control of Blue Mold on field tobacco.  It is a liquid suspension concentrate that contains 500 g/L of the active ingredient (a.i.) fenamidone.  Reason® 500 SC Fungicide is a broad-spectrum foliar fungicide that has both systemic and translaminar action, and belongs to the fungicide group 11. It is effective against several oomycetes including Peronospora tabacina, the pathogen that causes Blue Mold on tobacco.

Reason® 500 SC Fungicide has both preventive and protective activity and it works by inhibiting the pathogen’s spore germination and acts as an anti-sporulant.  It must be applied on the plant foliage as soon as crop and/or environmental conditions become favourable for Blue Mold development.

For resistant management, no more than one application of Reason® 500 SC Fungicide or other group 11 fungicide, such as Quadris Flowable Fungicide or Azoshy 250 SC, should be made before alternating with a fungicide from a different resistance management group registered and recommended for Blue Mold control.  Currently, the options are Aliette WDG, Actigard 50 WG and Presidio® Fungicide.

The application rate for Reason® 500 SC Fungicide is 400 to 600 mL/ha and should be applied on a 5 to 10 day interval depending upon disease conditions.  A maximum of 1600 mL/ha of Reason® 500 SC Fungicide applied per season to tobacco is permitted.  When applying Reason® 500 SC Fungicide, use sufficient water to guarantee good leaf coverage.

The re-entry interval (REI) after application is 12 hours and the pre-harvest interval (PHI) is 30 days.

The Canadian Tobacco Research Foundation (CTRF) evaluated Reason® 500 SC Fungicide in several field experiments and found the fungicide to have no detrimental effects on tobacco yield and quality.  The Tobacco Review and Evaluation Committee (TREC) also found the fungicide to be acceptable for use on flue-cured tobacco.

Even though Blue Mold on field tobacco has not occurred in Ontario since 2008, it is important that products be available for control in the event the disease reappears.

Always read the label before applying a pest control product.

The label for Reason® 500 SC Fungicide and other tobacco crop protection agents can be found on the Pest Management Regulatory Agency (PMRA) webpage: http://pr-rp.hc-sc.gc.ca/ls-re/index-eng.php

Post prepared and sent by Canadian Tobacco Research Foundation

Mailing Address: CTRF, P.O. Box 322, Tillsonburg, ON  N4G 4H5

Telephone: 519-842-8997

Web Address: http://ctrf1.com

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