Re-Evaluation Round-Up: Updates on Recent Registration Decisions Impacting Apple Growers

The Pest Management Regulatory Agency (PMRA) has released a number of re-evaluation decisions recently that impact apple growers. Below is a summary of these changes including important dates of last use.

All information on past and present re-evaluations can be found in the Pesticide Product Information Database on the PMRA website

The PMRA’s Re-evaluation and Special Review Work Plan 2020-2025 is also available on the PMRA website and lists anticipated dates for public consultation or final decision for pest control. However, with the on-going pandemic, there may be some delays in the release of certain documents.

Fungicides

Ethylene bisdithiocarbamate (EBDC)

The group of fungicides commonly referred to as EBDCs include the active ingredients, metiram (Polyram DF) and mancozeb (Penncozeb 75 Raincoat, Manzate Pro-Stick, Dithane Rainshield). An earlier review determined the cancellation of metiram due to worker exposure with a last date of use June 21, 2021. However, at that time, the PMRA retracted a similar final decision for mancozeb and a new re-evaluation decision was just released in November.

While strict risk-reduction measures have been put in place for use on apples, the good news is registration has been maintained for mancozeb. Registrants and retailers will have until November 19, 2022 to transition to newly amended labels. See Table 1 for a summary of the risk-reduction measures.

We are currently seeking clarification on the maximum applications per year. Based on the re-evaluation decision, the label will state maximum 4 (full rate) applications per year. It is unclear if half rates will be acceptable and what the maximum number of applications would be. Stay tuned for more information on this and considerations for apple scab management strategies.

Captan

The final decision for the active ingredient, captan will have growers seeing a change in use pattern and formulation for registered products. This decision was based on worker exposure issues. As a result, the currently registered products, Maestro 80 DF and Supra Captan 80 WDG are being phased out and are replaced by formulations with water soluble packaging.

The last date of sale by retailers for these products was Spring 2020. Growers have until May 10, 2021 to use up their supply, following the existing container label for rates, restricted entry interval (REI) and preharvest interval (PHI).  

The new WSP formulations for Maestro 80 and Supra Captan 80 are available. These labels can be found on the PMRA label search. All required use pattern amendments are reflected on the labels and must be followed when using these formulations. See Table 1 for a summary of this information.

Thiophanate-methyl

The most recent re-evaluation decision to be released was for the active ingredient, thiophanate-methyl (Senator 50 SC). After considerable effort and time for a decision to be made, use on apples has been retained. Currently on the label, there are higher labelled rates for use in British Columbia only. Moving forward, these will be removed and the Eastern Canada rate will become the national maximum application rate. Increased risk-reduction measures will also be implemented including a preharvest interval of 7 days and maximum applications per year of 2. Restricted entry interval remains at 12 hours. Registrant and retailers will have up to 24 months from decision publication date of December 3, 2020 to make appropriate label amendments.

Other fungicides

In addition to the products mentioned above, Granuflo T and Ferbam 76 WDG are also phased for cancellation. See Table 2 for more information on these products.

Table 1.  Use pattern amendments for the fungicide active ingredients, mancozeb (e.g., Dithane Rainshield, Manzate Pro-Stick, Penncozeb 75 Raincoat) and captan (e.g., Maestro 80 WSP, Supra Captan 80 WSP) and insecticide active ingredient, phosmet (e.g., Imidan WP)

Orchard type
Rate
Min. interval between applications
Max. applications per year
Restricted entry interval
Preharvest interval
MANCOZEB
All types
4.5 kg a.i. / ha 1 
7 days
4 (full rate) 2
12 hours (general re-entry)  
35 days (hand thinning)  
77 days
CAPTAN
High density
(max. canopy width per tree <2 m)
3 kg/ha 3
7 days
10
2 days (general re-entry)  
6 days (hand pruning, training)  
15 days (hand thinning, hand harvest)  
7 days 4
CAPTAN
Non-high density or standard
(max. canopy width per tree >2 m)
3 kg/ha 3
7 days
2
2 days (general re-entry)  
4 days (hand pruning, training)  
19 days (hand harvest)
24 days (hand thinning)  
7 days 4    
PHOSMET
All types
1.875 kg a.i./ha 1
14 days
2 (post-thinning only)
12 hours (general re-entry)  
9 days (hand pruning, scouting, training)  
22 days (hand harvest)
22 days
1 Depends on formulation
2 Currently no information is available on use of half rates. Stay tuned.
3 Important side note, the high rate is required for effective control of fruit rot, fly speck and sooty blotch. Do not use a reduced rate if these diseases are of concern.
4 Where restricted entry interval exceeds preharvest interval, use the longer interval.

Table 2. Pest control product cancellations (final decision) on apples

Pesticide Type
Product
Active Ingredient
Last Date of Use
Fungicide
Maestro 80 DF1
captan
May 10, 2021
 
Supra Captan 80 WDG1
captan
May 10, 2021
 
Polyram DF
metiram
June 21, 2021
 
Granuflo T
thiram
December 14, 2021
 
Ferbam 76 WDG
ferbam
December 14, 2021
Insecticide
Actara 25 WG2
thiamethoxam
April 11, 20213
 
Admire 240 F2
imidacloprid
April 11, 2021
 
Alias 240 SC2
imidacloprid
April 11, 2021
 
Clutch 50 WDG2
clothianidin
April 11, 20213
1These formulation of the active ingredient captan are currently being phased out. New formulations of Maestro and Supra Captan are now available.
2 Final decision for pollinator health special review.
3 A 1-year extension was granted for control of brown marmorated stink bug. Last date of use for this pest is Apr 11, 2022.

Insecticides

Phosmet

Originally proposed for cancellation, the re-evaluation decision for the active ingredient, phosmet (Imidan WP) will maintain registration with strict risk-reduction measures in place for use on apples. Registrants and retailers will have until October 30, 2022 to transition to newly amended labels. See Table 1 for a summary of the risk-reduction measures.

Neonicotinoids

A number of active ingredients belonging to the neonicotinoid insecticide group, including thiamethoxam (Actara 25 WG), imidacloprid (Admire 240 F, Alias 240 SC) and clothianidin (Clutch 50 WDG) have undergone special review for environmental concerns. The final decision for impacts to pollinator health and aquatic invertebrate special review have been released. All 3 active ingredients are being cancelled on apples.  

During the re-evaluation for Actara and Clutch, lack of alternatives for the management of brown marmorated stink bug (BMSB) were identified. As a result, a 1-year extension was granted to allow growers to use these products for control of BMSB until 2022. The Clutch label that has now been posted on the PMRA website reflects this change, listing only BMSB for apples. The PMRA, however, has confirmed that growers can still continue to use the container label until April 2021 for all currently registered pests. See Table 2 for more information.

Other insecticides

In addition to the products mentioned above, Matador 120 EC and Silencer 120 EC have been proposed for cancellation. See Table 3 for more information. 

Table 3. Anticipated date of final decision for pest control products registered on apples

Pesticide Type
Product
Active Ingredient
Proposed Action
Final Decision Expected
Insecticide
Madator 120 EC
lambda-cyhalothrin
cancellation
March 2021
 
Silencer 120 EC
lambda-cyhalothrin
cancellation
March 2021

Plant Growth Regulators

Ethrel

The re-evaluation decision for the active ingredient, ethephon (Ethrel) was published September 24, 2020 and will maintain registration on non-bearing trees but all uses on bearing trees such as promotion of early colouring, ripening, or loosing apples for harvest has been removed. This therefore revokes the 3 PPM maximum residue limit (MRL) on apples and juice and is now subject to the general MRL of 0.1 PPM.

In addition, stricter risk-reduction measures will now be in place including additional PPE requirements, restrictions on amount of ingredient handled per day, and longer restricted entry intervals for post-application activities on non-bearing trees (10 days for hand pruning/scouting/training, 2 days for transplanting, 12 hours for maintenance/weeding/other activities).

Registrants and retailers will have until September 24, 2022 to transition to newly amended labels. Similarly, users will also have the same 24-month period from the decision date to transition to the newly amended labels.


Kristy Grigg-McGuffin
Kristy Grigg-McGuffin

Horticulture IPM Specialist, OMAFRA

Cassandra Russell
Cassandra Russell

Tree Fruit Specialist (A), OMAFRA