Changes Coming for the Use of Chlorothalonil (Bravo®) Products

By Jill MacDonald, Perennia Research Associate

Chlorothalonil is a contact and protectant fungicide that controls a broad range of fungal diseases. It is used on a number of crops. Due to the recent re-evaluation of chlorothalonil by the Pest Management Regulatory Agency (PMRA) there are changes that will affect how growers use the product, in relation to how it is mixed, loaded and applied. The re-evaluation has caused a discontinuation of Bravo 500 and Ridomil Gold SL/Bravo Twin-Pak formulations. The final day that these products will be available for purchase is May 10th, 2020, and the final day that growers will be able to make applications of these products is May 10, 2021.  After this time, it will be the responsibility of the grower to properly dispose of any leftover product.

How will these changes affect how I use chlorothalonil products?

Changes to Number of Applications Permitted

There have been several changes made to the number of applications that are permitted on fruit and vegetable crops, it is important to check how your crop is affected. The full list of changes, including application rates and REIs can be found here.

A few of the crops that are undergoing changes to the number of applications permitted per season:

Crop	2019	2020
Blueberry (HB)	3	2
Cabbage	5	2
Celery, field	9	2
Cherries (sweet and sour)	4	3 (2 spring + 1 post-harvest)
Cole Crops	5	1
Cranberries	3	1
Cucurbit Vegetables	7	2
Onion, dry bulb	3	2
Onion, green bunching	5	2
Peach, nectarine	4	3 (2 spring + 1 dormant)
Potato, table	12	3
Tomato (not for processing)	9	2
Wheat	3	2

Additional PPE, Buffer Zone Changes and REI

New requirements have been put in place to protect the applicator and persons who are handling the product, by increasing the amount of personal protective equipment (PPE) required. It is recommended to read the revised product label to obtain information on PPE and changes to the buffer zone requirements and restricted entry intervals (REI) for certain activities. Growers are reminded to have the updated label available to staff members who may come in contact with the product, as well as making them aware of the changes.

Implementation of Vegetative Filter Strips

Use of chlorothalonil requires a 10 meter (32’) vegetative filter strip (VFS) to be planted, if there is an aquatic ecosystem downhill from the field or sprayed area. A VFS is different than spray buffer zones: the filter strip is typically perennial, hardy, deep-rooted native vegetation that can slow runoff and filter out any pesticides that the runoff may contain. 

  

Figures were obtained from: https://www.syngentaebiz.com/dotnetebiz/imagelibrary/Vegetative_Strip_ECU_Bulletin_2019.pdf?utm_source=pardot&utm_medium=lp&utm_campaign=895&utm_content=en

Introduction of Closed-system Transfer

The PMRA will now require growers, under certain circumstances, to use a closed-transfer and application system. The closed-system transfer specifically focuses on mixing and loading of the product. All potato applications, or any applications when more than 340 kg a.i. are handled in one day will be subject to these requirements.  When product is directly transferred from the tote to the sprayer tank, this will now require dry poppet connections which comply with closed-transfer. Dry poppets are available from several manufactures and are also known by several names, such as dry poppet couplings or valves. Syngenta currently supplies a female dry poppet to male cam lever adapter with each tote of Bravo Zn. Many chemical handling systems and sprayers are fitted with cam lever connections from the factory, in this case you can purchase a dry poppet to cam lever adapter. The existing dry poppet valves on the 450L totes of Bravo®ZN are already compliant with the closed-system transfer requirement and will not need to be altered.

Figures were obtained from: https://www.syngentaebiz.com/Media_Upload/Pdfs/SY_19_WhitePaper_BravoZNClosedSystem_R3.pdf?utm_source=pardot&utm_medium=lp&utm_campaign=895&utm_content=en

Additional Important Changes

Hand harvesting of processing tomatoes and application through irrigation systems on strawberries and cucurbits (cantaloupe, muskmelon, honeydew, squash, pumpkin, watermelon and cucumber) is now prohibited.

For further details, please visit Syngenta.ca.

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New pesticide registrations

Agri-Réseau is a resource available through The Centre de référence en agriculture et agroalimentaire du Québec (CRAAQ).  Every month, they publish a list of new phytoprotection registrations.  At Perennia, we are fortunate to have Mélanie Leclerc as part of our staff, and she has translated the March list of new pesticide registrations for Fruit Trees, Field Crops, Vegetables, Greenhouse, Berries, Ornamental, and "Other" (hops, hemp, quinoa, and basil), which can be found here.

From the Vegetable side, the main excitement is a few more weed control options in asparagus, Brassicas, and shallots, and some new disease management options in asparagus, kohlrabi, Brassica leafy greens, and bulb vegetables (Group 3-07A and 3-07B, so bulb onions, garlic, shallots, green onions, leeks, etc.)

Field Day: What's the Deal with Delia?

Join us on a field tour on Thursday, July 9th, 2015 from 8:15 am to noon!  

Come learn more about onion maggots (Delia antigua) and other Delia species that attack onions, corn, beans, and Brassicas such as cabbage, broccoli, cauliflower, radishes, kale and Brussel sprouts.

Figure 1. Onion maggot damage.

AAFC is currently conducting research to determine which Delia species are present in Nova Scotian onion fields and to determine if surrounding vegetation or field history can influence Delia populations and subsequent damage.

Netting and floating row cover can be powerful tools to combat insect pests such as cabbage root maggot (Delia radicum). Perennia and AAFC are currently conducting research into the efficacy of different netting mesh sizes. A Wondermesh Netting/Row Cover Retriever will be on hand to demonstrate technology that makes using netting and row covers easier!

Figure 2. Wondermesh Netting/Row cover Retriever.

Carrot weevils (Listronotus oregonensis) are sporadic pests of carrots. Current AAFC studies are evaluating the carrot weevil’s movement within the field and identifying overwintering sites.

Please call Gail at (902) 678-7722 or visit www.perenniaregistrations.com
to register!

Coffee and muffins at 8:15 AM at the Kentville Research Station - bus leaves at 8:30 AM sharp!

Nitrogen

Nitrogen (N) is easily leached from the soil.  If this happens, money is wasted and ground water may be contaminated.  Nitrogen applications should be timed to meet crop demands.  Large pre-plant broadcast N applications should be avoided.  If needed, additional N can be applied by topdressing, side-dressing or injection into a trickle irrigation system.

Leafy greens, fruiting vegetables and cole crops require larger amount of nutrients and  in general require additional Nitrogen to be applied.  Heavy rainfall events may cause leaching and on sandy soils 20-40 kg/N per hectare can be lost. 

 Nitrogen deficiency in collards

It is recommended that tissue samples be taken and sent for analysis to determine nutrient levels in the plant tissue, so an adequate fertilizer regime can be established.

Cabbage Maggot Observed Recently

 Cabbage maggot at base of wilted plant.

Cabbage maggot pressure continues to be very high this growing season.  Growers need to apply insecticide at cole crop transplanting and then within 2-3 weeks.  It is important to ensure that PHI is met.  Aside from chemical control, crop rotation contributes to keeping populations low.  Fall tillage to bury crop residues and to expose over-wintering pupae helps reduce overwintering populations.

Floating row covers and insect nettings provide an effective barrier against this pest. Place the cover as soon as the transplants are set.  Do not use where the same crop family -- brassicas or onions -- were grown last year, as flies left in soil could emerge under the cover. Place cover over the crop at the time of seeding or transplanting and seal the edges with soil.