INTRODUCTION

1. WHAT IS FUNGICIDE RESISTANCE?

Resistance by fungal pathogens to fungicides usually evolves following the intensive use of fungicides for disease control. In any fungal population there are likely to be individuals that have some degree of natural resistance and which are less susceptible to fungicides, even before the chemicals are used. Resistance arises through the incorrect use of fungicides by selection of the resistant forms of fungi. Continued use of a fungicide or fungicide chemical group can result in a significant build-up of resistant individuals in the fungal population – to the point where that particular product, or other products from the same chemical group, is no longer effective.  In some cases, removal of the selection pressure can result in the fungal population regaining its sensitivity to the fungicide group, but this is not always the case. The risk of fungicide resistance developing varies between different chemical groups and different fungal pathogens, such that specific strategies are recommended for those situations considered to carry the highest risk.

2. WHAT CAN BE DONE TO PREVENT OR DELAY RESISTANCE?

2.1  The most common approach to managing fungicide resistance is through responsible use of fungicides, of which the resistance management strategies presented in this document are good examples. In their most basic form, these strategies advocate rotation of fungicide products with a different chemical activity group to prevent over-use of any one product or activity group. More complex strategies safeguard against the development of cross-resistance or resistance to multiple chemical groups. In Australia, all fungicide products are labelled to identify which activity group they belong to. The activity group is indicated by a number (or letter/number combination) code on the product label.

2.2  Selecting the most effective or appropriate way to apply fungicides will make them work better and assist in delaying the development of resistance. A good understanding of the pathogen’s life cycle and epidemiology will also help in the selection of the most appropriate application method.  As a general rule, targeted applications to control a certain development stage or population level are most effective, whereas shotgun approaches like application of fungicides through irrigation systems could accelerate the development of resistance by exposing a large portion of the fungal population to sub‑lethal rates.  Particular attention should be given to label recommendations, rates and coverage. Adherence to suggested disease threshold levels is also good resistance management practice.

2.3   The use of cultural practices or growing varieties of crops with a high degree of natural resistance to diseases – requiring fewer or less frequent fungicide applications.

2.4   Working with industry bodies such as the CropLife Australia Fungicide Resistance Management Review Group to establish resistance management strategies for minor crops and/or those crops for which no strategies exist.  Of particular concern are permitted uses of fungicides, often in minor crops, where repeated use of a limited number of fungicide alternatives occurs.  Although not explicitly stated on agricultural use permits, such permitted uses should also incorporate measures to prevent resistance.

2.5  In the event of tank mixing products and/or co-formulations, always follow the recommendation from the most recent Fungicide Resistance Management Strategies and apply the apply the most stringent strategy applicable to the pathogen most at risk of developing resistance.

2.6 Certain environments are conducive to continuous infection and consistently high disease pressure. Examples of such environments are nurseries, tunnels, glasshouses and other structures of protected cultivation.  Because protected cultivation usually requires multiple applications of fungicides at short intervals to control high disease incidence, these are often the origin of resistance to fungicides.  Users of fungicides should be particularly mindful of the resistance risk under these conditions.  Do not use a fungicide product to which resistance has been confirmed and stop using a product if resistance is suspected.  When the fungicide in question no longer gives adequate control, stop using it temporarily and consult the supplier on its current resistance status.

2.7 In the absence of an established resistance management strategy for a particular crop/disease situation, it is recommended that the use of fungicides from any given activity group (excluding Group M) be limited to a maximum of one‑third of the total number of fungicide applications. The use of consecutive applications of fungicides from the same activity group should also be limited by alternating between products from different activity groups.  The use of Group M fungicides is not limited, as these fungicides carry an inherently low risk of fungicide resistance developing.

3. ACTIVITY GROUP LABELLING IN AUSTRALIA

In order to help fungicide users to manage fungicide resistance, all fungicide products sold in Australia are classified according to the chemical activity group of their active constituent.  The activity group must be indicated by a letter code on the product label.  Australia was the first country to introduce compulsory activity group labelling on products.  Since the introduction of activity group labelling in Australia, other countries have adopted activity group classification systems, however caution should be shown if cross-referencing activity groups between Australia and other countries, as there are some differences in classification.

4. CHANGES TO ACTIVITY GROUPS

In 2008, CropLife Australia completely revised Australia’s fungicide activity grouping system to bring it into line with the international Fungicide Resistance Action Committee (FRAC) activity group classification system.  This was the first major revision of the Australian classification system since its introduction several years ago.  Activity group codes have now been changed from letters to numbers (or letter/number combinations).  For a complete list of all fungicide active constituents registered in Australia and their old and new activity groups, see the Fungicide Activity Group Table on the CropLife Australia website at www.croplife.org.au.

RESISTANCE RISK

Table 1:       Plant pathogens accepted as showing a medium risk of development of resistance to fungicides

FRAC PathogenCropDisease
Bremia lactucaeLettuceDowny mildew
Gibberella fujikuroi*RiceBakanae
Leptosphaera nodorum
(Stagonospora nodorum)
WheatLeaf spot
Monilinia spp.Stone and pome fruitMonilinia rots
Mycosphaerella graminicola
(Septoria tritici)
WheatSeptoria
Mycosphaerella musicolaBananaYellow Sigatoka (Leaf Spot)
Peronospora spp.VariousDowny mildew
Podosphaera leucotrichaApplePowdery mildew
Puccinia spp.Wheat/barleyRusts
Pyrenophora teresBarleyNet Blotch
Pyrepnophora tritici-repentisWheatTan spot (yellow spot)
Tapesia spp.Wheat/barleyEyespot
Erysiphe necator *GrapevinePowdery mildew

Table 2:       Plant pathogens accepted as showing a high risk of development of resistance to fungicides (adapted from EPPO, 2002)

Table 2: Plant pathogens accepted as showing a high risk of development of resistance to fungicides (adapted from EPPO, 2002)

FRAC PathogenCropDisease
Botryotinia fuckeliana
(Botrytis cinerea)
Various, especially grapevineGrey mould
Erysiphe graminisWheat / barleyPowdery mildew
Mycosphaerella fijiensisBananaBlack sigatoka
Phytophthora infestansPotatoLate blight
Plasmopara viticolaGrapevineDowny mildew
Pseudoperonospora cubensis and relatedCucurbitsDowny mildew
Pyricularia oryzae RiceRice blast
Sphaerotheca fuligenea and relatedCucurbitsPowdery mildew
Venturia spp.Apple, pearScab

Table 3:       Plant pathogens for which resistance has been confirmed in Australia.  Users are advised to at all times adhere to appropriate resistance management Strategies.

Table 3: Plant pathogens for which resistance has been confirmed in Australia. Users are advised to at all times adhere to appropriate resistance management strategies.

FRAC Pathogen Crop Resistance confirmed against FRAC
Group
Disease
Botrytis cinerea StrawberriesIprodione 2Grey mould
Strobilurins11
Strobilurins9
Fenhexamid 17
Blumeria graminis f.s.p. hordei BarleyTebuconazole 3Powdery mildew
Podosphaera xanthii CucurbitsBuprimate 8Powdery Mildew
Strobilurins 11
Triadimenol 3
Erysiphe necator GrapesStrobilurins11Powdery mildew
Venturia inaequalis ApplesTriazoles 3Black spot
Plasmopara viticola GrapesPhenylamides 4Downy mildew
Mycosphaerella musicola BananasStrobilurins 11Yellow sigatoka

Pathogens with high resistance risk:

In some cases, fungicides from additional fungicide activity groups may be available under permit for use in the above crop/pest situations.  Details of such permits can be obtained from the Australian regulator’s (APVMA) website: (www.apvma.gov.au).   In the absence of a resistance management strategy for activity groups of products available under permit, or in the absence of restrictions contained within the permit, it is strongly advised that those products (excluding Group M fungicides) be used in alternation with registered products from other fungicide activity groups, which should be used in accordance with the following resistance management strategies.

Pathogens with medium or unlisted resistance risk

In some cases, fungicides from additional fungicide activity groups may be available under permit for use in the above crop/pest situation.  Details of such permits can be obtained from the Australian regulator’s (APVMA) website:  (www.apvma.gov.au).  In the absence of a resistance management strategy for activity groups of products available under permit, it is advised that spray programs incorporating those products (excluding Group M fungicides) also incorporate registered products from other fungicide activity groups, which should be used in accordance with the following resistance management strategies.

Crop(s):          Almonds

Pest(s):           Blossom Blight and Brown Rot

Resistance Management Strategy for:

Group 2           (Dicarboximide) fungicides;

Group 3           (DMI);

Group 7           SDHI (Succinate dehydrogenase inhibitors)

Group 11         (Quinone outside inhibitor) fungicides

1. DO NOT apply consecutive sprays of products containing Group 11.

2. DO NOT apply more than three Group 3, Group 7 or Group 11 sprays per season (this includes mixture of Group 3 + 11 and Group 7 + 11).

3. DO NOT apply more than two Group 2 sprays in one season. Apply no more than two consecutive sprays before changing to another group.

4. If applying Group 7 fungicides, DO NOT apply more than two consecutive sprays before changing to another group. DO NOT apply more than three Group 7 sprays per season. If consecutive sprays are used, then use the same number of sprays of an alternative group before using another Group 7, including sprays in consecutive seasons.

5. Consecutive application include from the end of one season to the start of the following season.

6. Alternate with products from Groups M2, M3 and M4.

7. The spray program should be considered and the strategy applied on a whole-orchard basis.

Crop(s):          Almonds

Pest(s):           Rust

Resistance Management Strategy for:

Group 3           (DMI);
Group 7           SDHI (Succinate dehydrogenase inhibitors)
Group 11         (Quinone outside inhibitor) fungicides

  1. DO NOT apply consecutive sprays of products containing Group 7 or 11
  2. DO NOT apply three Group 3, Group 7 or Group 11 sprays per season (this includes mixture of Group 3 + 11 and Group 7 + 11).
  3. If two consecutive sprays of Group 3 are used, then use the same number of sprays of an alternative group before using another Group 3 , including sprays in the following seasons.
  1. Alternate with products from Groups M2, M3 and M5.
  1. The spray program should be considered and the strategy applied on a whole‑orchard basis.

Crop(s):          Apples, Pears

Pest(s):           Apple and Pear Scab

Resistance Management Strategy for:

Group 3             (DMI);

Group 7             SDHI (Succinate dehydrogenase inhibitors);

Group 9             (Anilinopyrimidine);

Group 11            (Quinone outside Inhibitor); and

Group U12        (Cell membrane disruption) fungicides.

  1. To prevent or delay the onset of resistance to Group 3 fungicides.
    DO NOT apply more than four Group 3 sprays alone per season. If more sprays, are required apply a tank mix of a Group 3 with a Group 9 or suitable product from Groups M or M1 to M9, or apply a registered product containing a combination of a Group 3 and a Group 9 fungicide.
  1. DO NOT apply more than four sprays per season of Group 9 fungicides (solo products).DO NOT apply more than four sprays per season of products containing a combination of a Group 9 and a Group 3 fungicide and no more than two consecutive applications.DO NOT apply more than three sprays per season of Group 7 or Group 11 fungicides.  If two consecutive applications of Group 7 or Group 11 fungicides are used, then they must be followed by at least the same number of applications of fungicide(s) from a different group(s) before a Group 7 or Group 11 fungicide is used again, either in the current or following season. Where spray programs include solo Group 9 products and combination products, the maximum cumulative number of applications is four per season and no more than two consecutive applications. In locations where resistance has been reported use a Group 9 only in mixture with an effective non cross-resistant scab fungicide.
  1. To prevent or delay the onset of resistance to Group U12, DO NOT apply more than three consecutive sprays of Group U12, and no more than a total of six Group U12 sprays per season. If more sprays are required, tank mix Group U12 with a protectant product at the registered rate.

Crop(s):          Banana

Pest(s):           Yellow sigatoka

Resistance Management Strategy for:

Group 3              (DMI);

Group 11            (Quinone outside Inhibitor); and

Group 9             (Anilinopyrimidine) fungicides;

FAR NORTH QUEENSLAND

  1. De-leafing must be conducted in accordance with industry guidelines.
  1. Apply a regular schedule of protectant sprays.
  1. When disease potential is high, apply a maximum of two consecutive Group 3 sprays before changing to a fungicide of a different activity group.
  1. DO NOT apply more than six Group 3 sprays in any 12 month period.
  1. DO NOT apply any Group 3 sprays in the months of June, July, August and September . DO NOT apply more than two Group 11 sprays in any 12 month period.
  1. Group 11 fungicides should be applied in mixture with another fungicide from a different activity Group registered for the control of Yellow Sigatoka at the full registered rate.
  1. DO NOT apply consecutive sprays of Group 11
  1. Apply a minimum of two sprays from a different activity group between sprays of a Group 11 fungicide.
  1. DO NOT apply Group 11 sprays in the months of May, June, July, August and September.
  1. DO NOT apply more than six Group 9 sprays in any 12 month period.
  1. DO NOT apply more than two consecutive sprays of Group 9 fungicide before changing to a fungicide of a different activity group. When using consecutive applications of Group 9 fungicides, follow with at least as many different activity group fungicides before resuming with a Group 9 fungicides
Chemical Group Max. number of Applications/year Max. number of consecutive sprays Restricted

(no-spray) periods

Group 3 6 (& no more than 2 of 3 sprays) 2 June  to September inclusive
Group 11 2 (& no more than 1 of 3 sprays) Not allowed May to September inclusive
Group 9 6 (& no more than 2 of 4 sprays) 2 No restriction


EVERYWHERE EXCEPT FAR NORTH QUEENSLAND

1. When using Group 3 fungicides, apply a maximum of two consecutive Group 3 sprays before changing to a fungicide of a different activity group.

2. DO NOT apply more than five Group 3 sprays in any 12 month period.

3. DO NOT apply more than four Group 11 sprays in any 12 month period

4. DO NOT apply consecutive sprays of Group 11 fungicides.

5. Apply a minimum of two sprays from a different activity group between sprays of a Group 11

6. DO NOT apply more than five Group 9 sprays in any 12 month period.

7. DO NOT apply more than two consecutive sprays of Group 9 fungicides before changing to a fungicide of a different activity group. When using consecutive applications of Group 9 fungicides, follow with at least as many different activity group fungicides before resuming with a Group                  9 fungicide.

Chemical Group Max. number of

applications/year

Max. number of

consecutive sprays

Group 3 5 (& no more than 2 of 3 sprays) 2
Group 11 4 (& no more than 1 of 3 sprays) Not allowed
Group 9 5 (& no more than 2 of 4 sprays) 2


Crop(s):          Barley

Pest(s):           Powder Mildew

Resistance Management Strategy for:

Group 3        (DMI)

Group 7        (SDHI)

Group 11 + 3 (Quinone outside Inhibitor + DMI) treat as a Group 11

Group 11 + 4 (Quinone outside Inhibitor + PAA) treat as a Group 11

Group 13       (Aza-napthalene)

  1. Fungicides should be used as preventatively if possible or at first sign of disease. If disease is established within the canopy, fungicides may not produce optimal results and there is very strong potential to select for fungicide resistance. In high risk disease environments, integrated management approaches should be used to reduce fungicide resistance risk including the removal of stubble, control of green bridge volunteers and the use of tolerant and resistant varieties. Monitor if conditions favour disease development and reapply an appropriate fungicide from 21 to 28 days after first application. Use the higher label rate ranges where conditions favour disease development.
  1. DO NOT apply more than two applications per growing season of Group 7, 11 or 13 containing products. This includes in-furrow or seed treatments that have activity on foliar diseases. Combinations of in-furrow and seed treatment are counted as one application.
  1. Use Group 13 products in mixture, or alternate with fungicides of a different MOA. Always apply in mixture with a curative fungicide where disease is established.
  1. DO NOT apply consecutive applications of Group 11 containing products. This includes in-furrow i.e. If a Group 11 + 4 fungicide has been used in-furrow at planting, the first foliar fungicide spray must not contain a Group 11 fungicide.
  1. If a solo Group 7 seed treatment has been used with foliar activity (as determined by label claims), the first foliar fungicide applied should not contain a Group 7 fungicide.
  1. If a solo Group 7 seed treatment is being applied as a foliar spray it must be mixed with an effective, registered mixing partner.
  1. DO NOT apply more than three applications containing Group 3 fungicides per growing season. This total of three applications includes DMI’s applied as Group 11 + 3 co-formulations and in-furrow or seed treatments that have activity on foliar diseases. Combinations of in furrow and seed treatment are counted as one application.
  1. Minimise use of Group 3 fungicides which are known to have compromised resistance status.


Crop(s):          Barley

Pest(s):           Scald and Net blotch

Resistance Management Strategy for:

Group 3        (DMI)

Group 7        (SDHI)

Group 11 + 4       (Quinone outside Inhibitor + PAA)– Treat as a Group 11

Group 11 + 3      (Quinone outside Inhibitor + DMI)– Treat as a Group 11

  1. Fungicides should be used as protectant treatments – where no more than 5% leaf area infection evident anywhere in the canopy. In high risk disease environments, integrated management approaches should be used to reduce fungicide resistance risk including the removal of stubble, control of green bridge volunteers and the use of tolerant and resistant varieties.
  2. DO NOT apply more than two applications per growing season of Group 11 or 7 containing products. This includes in-furrow or seed treatments that have activity on foliar diseases. Combinations of in-furrow and seed treatment are counted as one application.
  3. DO NOT apply consecutive applications of Group 11 containing products. This includes in-furrow i.e. If a Group 11 + 4 fungicide has been used in-furrow at planting, the first foliar fungicide spray must not contain a Group 11 fungicide .
  4. If a solo Group 7 seed treatment has been used with foliar activity (as determined by label claims), the first foliar fungicide applied should not contain a Group 7 fungicide.
  5. If a solo Group 7 fungicide is being applied as a foliar spray it must be mixed with an effective, registered mixing partner.
  6. DO NOT apply more than three applications containing Group 3 fungicides per growing season. This total of three applications includes DMI’s applied as Group 11 + 3 co-formulations and in-furrow or seed treatments that have activity on foliar diseases. Combinations of in furrow and seed treatment are counted as one application.
  7. Minimise use of Group 3 fungicides which are known to have compromised resistance status

Crop(s):          Cucurbits

Pest(s):           Downy Mildew

Resistance Management Strategy for:

Group 4             (Phenylamide);

Group 11            (Quinone outside Inhibitor);

Group 28 + 43    (Carbamate plus Benzamide);

Group 40            (Carboxylic acid amide); and

Group 49         OSBP (Oxysterol binding protein inhibitor) fungicides

1. Applications made within the nursery count towards the total number of applications allowed per crop. It is recommended that disease control is started early and maintain a regular program using a fungicide from groups other than Group 4, 11, 28+43, 40 or 49.

2. When conditions favour disease development, DO NOT wait for disease to appear, but apply two consecutive sprays of a Group 4, 11, 28+43 or 49 products, at the interval recommended on the label, or a single spray of a Group 11 fungicide. Then resume the program of sprays using products from a different group to the Group 4, 11, 28+43 or 49 products just applied.

3. DO NOT apply more than four sprays of a Group 4 or of a Group 40 product per season.

4. DO NOT apply more than three sprays of a Group 49 product. Group 49 containing sprays should not consist of more than 33% of the total number of fungicide sprays per crop.

5. DO NOT apply more than two sprays of Group 11 or 28+43 fungicide per crop.

6. Apply Group 11 fungicides preventively.

7. Apply Group 4 and 49 fungicides preventatively and only in mixtures with an effective protectant fungicide from a different mode of action group.

8. Continue alternation of fungicides between successive crops. DO NOT make more than (6) six total applications of a Group 49 product per year on the same area targeting the same disease.

Crop(s):          Cucurbits

Pest(s):           Powdery Mildew

Resistance Management Strategy for:

Group 3              (DMI, pyrimidine);

Group 7              SDHI (Succinate dehydrogenase inhibitors);

Group 8              (Hydroxy-(2-amino-) pyrimidine)

Group 11             (Quinone outside Inhibitor) and other “systemic” fungicides;

Group 13            aza-napthalenes

Group U6           (Phenyl-acetamide); and

Group U8           (Actin Inhibitor) fungicides

1. Start disease control early. DO NOT wait for powdery mildew to appear before spraying, but start as soon as practicable after crop emergence.

2. Use protectant sprays in early crop growth. Apply protectant sprays up to the fruit set stage of the crop if the disease normally occurs during this period.  If this schedule is interrupted (eg. by rain) use a tank mix of protectant plus systemic before recommencing the protectant program

3. After fruit set, use systemic fungicides in one or more of the following ways:-

         a. Tank mix systemic fungicides with a protectant fungicide AND use fungicides from at least two different systemic activity groups per crop.

         b. Alternate systemic fungicides with a protectant fungicide AND use fungicides from at least two different systemic activity groups per crop.

         c. Alternate systemic fungicides from at least three different activity groups per crop. 

         d. Apply Group 11 fungicides preventatively.

4. Use a maximum of one Group 11 containing spray out of every three fungicide applications.

5. DO NOT use consecutive applications of Group 11 or Group U6 fungicides.

6. DO NOT apply more than two Group 11 or Group U6 products per crop.

7. DO NOT apply more than three Group 7 or Group 13 products per crop and no more than two consecutive applications per year.

Crop(s):          Fruit (post-harvest treatment)

Pest(s):           Post-harvest diseases

 Resistance Management Strategy for:

Group 2              (Dicarboximide); and other “systemic” fungicides; and

Group 3              (DMI);

Group 9              (Anilinopyrimidine) fungicides

Group 12            (Phenylpyrroles) fungicides

        1. For the last pre-harvest spray, use a fungicide with a different activity group to the fungicide planned for use as a post-harvest treatment.
        1. Where alternatives are available, rotate to use as many different activity groups as possible.
        1. DO NOT dispose of unused dip solutions as a spray to crops or orchards.
        1. DO NOT dispose of unused dip solutions within or near the crop or orchard area.

Crop(s):          Grape

Pest(s):           Downy Mildew

Resistance Management Strategy for:

Group 4            (Phenylamide);

Group 11          (Quinone outside Inhibitor);

Group 21          (Quinone inside Inhibitor);

Group 40          (Carboxylic acid amide); and

Group 45          (Quinone outside inhibitor, stigmatellin binding type) fungicides

        1. Apply all these fungicides preventatively, Group 4 fungicides should be applied before the first sign of oilspots or as soon as possible after an infection period.
        1. Mixtures – co-formulations or tank mixes with label rate of alternative mode of action
        1. Apply a maximum of two consecutive applications of any one group.
        1. Start preventative disease control sprays using non-Group 4 protectant fungicides, typically when shoots are 10-20cm long. Continue spraying at intervals of 7-21 days depending on disease pressure, label directions and rate of vine growth.
        1. Limit the use of Group 4 fungicides to periods when conditions favour disease development. Always apply Group 4 fungicides in mixtures.
 GroupGroupGroupGroupGroup
41121 (+M1)4045 (+40)
Max. number of consecutive applications2None222
Max. number of solo spraysNone232 (50%)
None
Max. number of sprays per season4-mix234–mix
(50% )
4-mix
Areas of higher agronomic riskMix Mix N/AMix N/A

6. Group 40 – do not apply as the last spray of the season.
    Group 40 – apply a maximum of 50% of the total number of downy sprays

7. Group 11 – If applied alone, do not make consecutive applications.

8. Group 11 – apply a maximum of 2 sprays per season, including mixtures.

Crop(s):          Grape

Pest(s):           Powdery Mildew

Resistance Management Strategy for:

Group 3            Demethylation inhibitors (DMI)

Group 5            Amines (morpholines);

Group 7            Succinate dehydrogenase inhibitors (SDHI);

Group 11          Quinone outside inhibitors (QoI) and combinations of Group 3;

Group 13          Aza-napthalenes;

Group U6         Phenyl-acetamide; and

Group U8         Actin disruptors (aryl-phenyl-ketone) fungicides

        1. Apply all these fungicides preventatively
        1. Consecutive applications include from the end of one season to the start of the next.
        1. Mixtures – co-formulations or tank mixes with label rate of alternative mode of action
    Group
3 5 7 11 (3) 13 U6 U8
Maximum number of consecutive sprays 2 2 none refer to 2 2 2
Maximum number of sprays per season 3 3 3 2 3 2 4 

 

4. Group 11 – where these fungicides have been routinely used for many seasons, field research indicates there is an increased risk of powdery mildew resistance. To ensure effective powdery mildew control in these circumstances, either use alternative modes of  action or apply in mixtures.
Group 11 – If applied alone, do not make consecutive applications.
Group 11 – apply a maximum of 2 sprays per season, including mixtures.

Crop(s):          Grape

Pest(s):           Grey Mould (Botrytis Bunch Rot)

Resistance Management Strategy for:

Group 2              (Dicarboximide);

Group 7              SDHI (Succinate dehydrogenase inhibitors);

Group 9              (Anilinopyrimidine) and combinations of Group 9 (Anilinopyrimidine) and  Group 12  (Phenylpyrroles);

Group 11            (Quinone outside Inhibitor) and combinations of Group 11 and Group 3;

Group 17            (Hydroxyanilide);

  1. Apply all these fungicides as protectants before the first sign of disease
  2. Consecutive applications include from the end of one season to the start of the next
  3. Varying the number of fungicides applied targeting Botrytis changes the relative resistance risk to any one fungicide group. When three or fewer sprays are applied, it is recommended that three different groups of fungicides are used (see table below). When four sprays are applied, try to use 3 or 4 different groups of fungicide

    1.  Maximum recommended number of sprays which
      can contain group

      279
      (inc 9+12)
      11
      (inc 3+11)
      17
      Total
      number of
      botrytis
      targeting
      sprays

      111111
      211111
      311111
      422222
      5+22222
      1. Group 11 or 7 fungicide is used solo, it should only be used in strict alternation with fungicides from a different mode of action group/li>
      1. DO NOT apply more than two consecutive sprays from the same fungicide group, for any Group 2, 7, 9 (including combinations with Group 12) 11+3 or 17 fungicide, including from the end of one season to the start of the following season
      1. If two consecutive applications of Group 11+3 fungicides are used, then they must be followed by at least the same number of applications of fungicide(s) from a different group(s) before a Group 11 (including combinations with Group 3) fungicide is used again, either in the current or following season.
      1. If resistance to a fungicide group has been detected, only use that fungicide group in mixtures or in strict alternation with fungicides from a different cross resistance group. A fungicide group that has been applied as the final application of the season should not be the first fungicide in the following season.

 Crop(s):         Lettuce

Pest(s):           Botrytis & Sclerotinia

Resistance Management Strategy for:

Group 2              (dicarboximide)

Group 7              SDHI (Succinate dehydrogenase inhibitors)

Group 9              (anilinopyrimidine)

Group 11            (Quinone outside inhibitor) and

Group 12            (phenylpyrroles) fungicides

        1. Apply Group 2 fungicide as a seedling drench soon after emergence.
        1. Apply a protectant fungicide as a high volume foliar spray before planting out, then a Group 2 fungicide immediately after planting.
        1. Maintain a cover with protectant fungicide sprays at 7-10 day intervals.
        1. If weather conditions favour Botrytis infection, tank mix the protectant with a Group 2
        1. DO NOT apply Group 2 fungicides more than four times per season, irrespective of the target disease.
        1. DO NOT apply more the two Group 9 or Group 12 fungicides per crop.
        1. DO NOT apply more than three Group 7 or Group 11 fungicides per crop and no more than two consecutive sprays per crop.

Crop(s):          Lettuce

Pest(s):          Downy Mildew

Resistance Management Strategy for:

Group 4              (Phenylamide);

Group 28 + 43   (Carbamate plus Benzamide);

Group 40            (Carboxylic acid amide); and

Group 49         OSBP (Oxysterol binding protein inhibitor) fungicide

1. Applications made within the nursery count towards the total number of applications allowed per crop. It is recommended that disease control is started early and maintain a regular program using a fungicide from groups other than Group 4, 40, 49, or 28+43.

2. When conditions favour disease development, DO NOT wait for disease to appear, but apply two consecutive sprays of a Group 4, 40, 49 or 28+43 product at the interval recommended on the label. Then resume the program of sprays using an alternative fungicide group to what was just applied.

3. DO NOT apply more than four sprays of a Group 4 or 40 product per season.

4. Group 49 fungicides should only consist of a maximum of 33% of the total fungicide sprays per season targeting downy mildew.

5. DO NOT apply more than three sprays of a Group 49 or 28+43 product per crop

6. Apply Group 4 and 49 fungicides preventatively and only in mixtures with effective protectant fungicide from a different mode of action group.

7. Continue alternation of fungicide modes of action between successive crops. DO NOT make more than (6) six total applications of a Group 49 product per year on the same area targeting the same disease.

Crop(s):          Onion (allium spp.)

Pest(s):           Downy Mildew

Resistance Management Strategy for:

Group 4              (Phenylamide);

Group 28 + 23    (Carbamate plus Benzamide);

Group 40            (Carboxylic acid amide) fungicides; and

Group 49         OSBP (Oxysterol binding protein inhibitor) fungicides

        1. Start disease control early and maintain a regular program using a fungicide from groups other than Group 4, 40 or 49.
        1. When conditions favour disease development, DO NOT wait for disease to appear, but apply two consecutive sprays of a Group 4, 28 + 43, 40 or 49 product at the interval recommended on the label. Then resume the program of sprays using products from a different mode of action group to the Group 4, 28 + 43, 40 or 49 products just applied.
        1. DO NOT apply more than four sprays of a Group 4 or 40 product per season.
        1. DO NOT apply more than three sprays of a Group 28 + 43 or 49 product per crop.Group 49 containing sprays should not consist of more than 33% of the total number of fungicide sprays per crop.
        1. Apply Group 4 and 49 fungicides preventatively and only in mixtures with effective protectant fungicides from a different mode of action group.
        1. Continue alternation of fungicides between successive crops. DO NOT make more than (6) six total applications of a Group 49 product per year on the same area targeting the same disease

Crop(s):          Ornamentals

Pest(s):          Grey Mould

Resistance Management Strategy for:

Group 2              (Dicarboximide) fungicides; and

Group 9              (Anilinopyrimidine)

        1. If three or fewer Botrytis fungicide sprays are applied per crop, use only one spray containing a Group 9.  If four to six sprays are applied per crop, use a maximum of two sprays containing Group 9 fungicides.  If seven or more sprays are applied per crop use a maximum of three sprays containing Group 9 fungicides. Avoid applying more than two successive sprays of a Group 9 fungicide, including from the end of one season to the next.
        1. DO NOT apply more than two consecutive sprays of a Group 2

Crop(s):          Passionfruit

Pest(s):           Alternaria sp.

Resistance Management Strategy for:

Group 2             (Dicarboximide); and

Group 11            (Quinone outside Inhibitors) fungicides

        1. Maintain a protective cover with a protectant fungicide such as mancozeb.
        1. Limit the use of Group 2 to strategic periods, i.e. before, during and after extended wet periods. Always tank mix the Group 2 fungicide with a protectant such as mancozeb. DO NOT apply more than four Group 2 sprays in a season.
        1. The total number of Group 11 sprays should be no more than one-third of the total number of fungicide sprays per season. DO NOT apply more than two consecutive applications of a Group 11 spray. If two consecutive applications of a Group 11 spray are applied, they must be followed by at least the same number of sprays from an alternative chemical group.

Crop(s):          Peanut

Pest(s):           Leaf Spots, Rust, Net Blotch

Resistance Management Strategy for:

Group 3              (DMI); and

Group 11            (Quinone outside Inhibitor) fungicides

        1. DO NOT apply more than three consecutive Group 3 sprays alone, before changing to a fungicide of a different activity group.
          Apply a maximum of five Group 3 sprays per season.
        1. DO NOT apply Group 11 products as more than 50% of the total number of sprays in any one season, up to a maximum of three sprays of Group 11.DO NOT apply more than two consecutive applications of a Group 11 spray.
          If two consecutive applications of a Group 11 spray are applied, they must be followed by at least the same number of sprays from an alternative chemical group.

Crop(s):          Poppies

Pest(s):           Downy Mildew

Resistance Management Strategy for:

Group 4            (Phenylamide);

Group 11           (Quinone outside Inhibitor);

Group 28 + 43      (Carbamate plus Benzamide);

Group 40          (Carboxylic acid amide); and

Group 49       OSBP (Oxysterol binding protein inhibitor) fungicides

        1. Start disease control early and maintain a regular protectant program. Fungicide applications need to start before the 6 leaf stage for early season control to be effective.
        1. When conditions favour disease development (high humidity, still weather, overcast skies), prior to visible disease symptoms (white downy growth on the underside of lower leaves followed by brown angular lesions) apply a single spray of a Group 49 fungicide, or up to two consecutive sprays of a Group 4, 11, 40 or 28 + 43 product (including mixtures containing Group 4, 11 or 40), at the interval recommended on the label. Then resume the program of sprays using products from a different group to the Group 4, 11, 40, 49 or 28 + 43 products just applied.
        1. DO NOT apply more than two sprays per season of a product containing a Group 4, 11 or 40 fungicide. DO NOT apply more than one spray of a product containing a Group 49 fungicide per season and ensure this does not exceed 33% of the of the total number of fungicide sprays per season.
        1. DO NOT apply more than three sprays of a Group 28+43 product per crop
        1. Apply Group 11 fungicides preventatively.
        1. Apply Group 4 and 49 fungicides preventatively and only in mixtures with effective protectant fungicide from a different mode of action group.
        1. DO NOT use a Group 49 product if it will be the last fungicide applied to the crop.

Crop(s):          Potato

Pest(s):           Late Blight (Irish Blight)

Resistance Management Strategy for:

Group 4              (Phenylamide);

Group 11             (Quinone outside Inhibitor);

Group 28 + 43 (Carbamate plus Benzamide);and

Group 40            (Carboxylic acid amide) fungicides

        1. Start disease control early and maintain a regular program using a fungicide from groups other than Group 4, 11 or 40.
        1. When conditions favour disease development, DO NOT wait for disease to appear, but apply two consecutive sprays of a Group 4, 11, 40 or 28 + 43 fungicide at the interval recommended on the label. Then resume the program of sprays using products from a different group to the Group 4, 11, 40 or 28 + 43 fungicides just applied.
        1. DO NOT apply more than four sprays of a Group 4 or 40 fungicide per season.
        1. DO NOT apply more than two sprays of a Group 28 + 43 product per crop.
        1. Apply Group 11 fungicides preventively. The total number of Group 11 fungicide applications per season should not exceed one third of the total number of fungicide applications per crop. No more than two consecutive Group 11 sprays should be applied.  If consecutive applications of Group 11 fungicides are used, then they must be followed by at least the same number of applications of fungicide(s) from a different group(s) before a Group 11 fungicide is used again, either in the current or following season.

Crop(s):          Potato

Pest(s):           Target Spot (Early Blight)

Resistance Management Strategy for:

Group 2            (Dicarboximide);

Group 3            (DMI);

Group 7            SDHI (Succinate dehydrogenase inhibitors)

Group 9            (Anilinopyrimidine);

Group 11           (Quinone outside Inhibitor); and

Group 11 + 3 (Quinone outside Inhibitor + DMI) treat as a Group 11 fungicide for resistance management purposes.

        1. Limit the use of Group 2, 3, 9 or 11 fungicides to periods when conditions favour disease development.
        1. DO NOT apply more than six Group 2 sprays in one season. Apply no more than two consecutive sprays of a Group 2
        1. DO NOT apply more than six Group 3 sprays in a season. Apply no more than two consecutive sprays of a Group 3 fungicide alone.
        1. If three or fewer fungicide sprays for target spot are applied per crop, use only one spray containing a Group 7 If four to six sprays are applied per crop, use a maximum of two sprays containing Group 7 fungicides.  If seven or more sprays are applied per crop use a maximum of three sprays containing Group 7 fungicides. If used solo, apply Group 7 fungicides in strict alternation with fungicides from a different cross resistance group. If fungicides containing Group 7 are used in mixture, apply a maximum of 2 consecutive applications.
        1. If three or fewer fungicide sprays for target spot are applied per crop, use only one spray containing a Group 9 If four to six sprays are applied per crop, use a maximum of two sprays containing Group 9 fungicides.  If seven or more sprays are applied per crop use a maximum of three sprays containing Group 9 fungicides.Apply no more than two consecutive sprays containing a Group 9 fungicide.
        1. Apply Group 11 containing fungicides preventively. DO NOT apply more than three foliar applications of a Group 11
          containing fungicide per crop, no more than two consecutive Group11 sprays per crop.  If consecutive applications of Group 11 containing fungicides are used, then they must be followed by at least the same number of applications of fungicide(s) from a different group(s) before a Group 11 containing fungicide is used again, either in the current or following season.When using a Group 11 fungicide in-furrow at planting, use a fungicide from a different group as the first foliar spray.

Crop(s):          Pulse Crops

Disease (s):  Grey Mould (Botrytis)

Resistance Management Strategy for

Group 1              (Methyl Benzimidazole Carbamates);

Group 2              (dicarboximide);

*Group 3 + 11    (DMI + Quinone outside Inhibitor);

Group M3          (dithiocarbamate); and

*Group M4        (Phthalimide) fungicides

        1. DO NOT apply more than two Group 1, 2, 3+11, M3 or M4 sprays in one season (including seed treatment).
        1. DO NOT apply more than two consecutive Group 1 or M3 sprays, including from season to season and seed treatments. The final foliar spray of the previous season should be considered when planning which fungicide group to use in seed treatments and the first foliar application.
          *Note currently only available under temporary permit. Always check that permits are valid prior to use.

Crop(s):          Stone Fruit

Pest(s):           Blossom Blight and Brown Rot

Resistance Management Strategy for:

Group 2             (Dicarboximide);

Group 3             (DMI);

Group 7             SDHI (Succinate dehydrogenase inhibitors) and

Group 9             ((Anilinopyrimidine)fungicides

        1. If applying Group 2 or Group 3 fungicides, DO NOT apply more than two consecutive sprays of fungicides from the same group before changing to another group.
        1. DO NOT apply more than three sprays of a Group 9 fungicide per season. If two or three consecutive sprays are applied, they must be followed by at least the same number of sprays from an alternative chemical group, including from one season to the next.
        2. If applying Group 7 fungicides, DO NOT apply more than two consecutive sprays before changing to another group. DO NOT apply more than three Group 7 sprays per season.  If consecutive sprays are used, then use the same number of sprays of an alternative group before using another Group 7, including sprays in consecutive seasons.
        1. A post-harvest treatment should also be counted as an application.
        1. The last blossom blight spray and the first pre-harvest brown rot spray should be regarded as consecutive applications.
        1. The spray program should be considered and the strategy applied on a whole-orchard basis.

Crop(s):          Strawberry

Pest(s):           Grey Mould (Botrytis)

Resistance Management Strategy for

Group 2              (Dicarboximide);

Group 7              SDHI (Succinate dehydrogenase inhibitors)

Group 9              (Anilinopyrimidine);

Group 12            (Phenylpyrroles); and

Group 17            (Hydroxyanilide) fungicides

        1. Apply a program of protectant fungicides during flowering. If conditions favour disease development during this period, use a Group 2, 9, 12 or 17
        1. DO NOT apply more than two successive sprays of Group 2, 9, 12 or 17
        1. If applying Group 7 fungicides, DO NOT apply more than two consecutive sprays before changing to another group. DO NOT apply more than three Group 7 sprays per season.  If consecutive sprays are used, then use the same number of sprays of an alternative group before using another Group 7, including sprays in consecutive seasons.
        1. If three or fewer Botrytis fungicide sprays are applied per crop, use only one spray containing a Group 9 If four to six sprays are applied per crop use a maximum of two sprays containing Group 9 fungicides.  If seven or more sprays are applied per crop use a maximum of three sprays containing Group 9 fungicides.
        1. If three or fewer Botrytis fungicide sprays are applied per crop, use only one spray containing a Group 12 If four to six sprays are applied per crop use a maximum of two sprays containing Group 12 fungicides.  If seven or more sprays are applied per crop use a maximum of three sprays containing Group 12 fungicides.

Crop(s):          Strawberry

Pest(s):           Powdery Mildew

Resistance Management Strategy for:

Group 3              (DMI);

Group 7              SDHI (Succinate dehydrogenase inhibitors) and

Group 11            (Quinone outside Inhibitor) fungicides

        1. Apply a program of protectant fungicides from early crop establishment and maintain a regular spray program throughout the crop growing cycle. If weather conditions favour powdery mildew development, use a Group 3 or Group 11
        1. DO NOT apply more than four Group 3 sprays per season.DO NOT apply more than two consecutive sprays of Group 3 fungicides, including from one season to the next.
        1. If applying Group 7 fungicides, DO NOT apply more than two consecutive sprays before changing to another group.
        1. DO NOT apply more than three Group 7 sprays per season. If consecutive sprays are used, then use the same number of sprays of an alternative group before using another Group 7, including sprays in consecutive seasons.
        1. Apply Group 11 fungicides preventively. DO NOT apply consecutive sprays of Group 11 fungicides, including from one season to the next.
        1. If three or fewer powdery mildew fungicide sprays are applied per crop, use only one spray containing a Group 11 If four to six sprays are applied per crop, use no more than two sprays containing a Group 11 fungicide.  If seven or more sprays are applied per crop use a maximum of three sprays containing a Group 11 fungicide. DO NOT apply more than three Group 11 sprays per season.
        1. DO NOT use Group 3 fungicides curatively. 

Crop(s):          Tomato

Pest(s):           Grey Mould

Resistance Management Strategy for:

Group 2              (Dicarboximide) fungicides; and

Group 7              SDHI (Succinate dehydrogenase inhibitors)

        1. Tank mix Group 2 fungicides with a protectant such as chlorothalonil. Avoid applying two Group 2 fungicides in succession, unless tank mixed with a protectant.
        1. DO NOT apply more than four Group 2 sprays in a season.
        1. If applying Group 7 fungicides, DO NOT apply more than two consecutive sprays before changing to another group. DO NOT apply more than three Group 7 sprays per season.  If consecutive sprays are used, then use the same number of sprays of an alternative group before using another Group 7, including sprays in consecutive seasons.

Crop(s):          Tomato

Pest(s):           Powdery Mildew

Resistance Management Strategy for:

 Group 11 + 3   fungicide mixture products

        1. Treat as a Group 11 fungicide for resistance management purposes.
        1. Apply only as a protectant treatment.
        2. DO NOT apply more than three sprays, or one third of the total sprays (whichever is the lower).
        1. DO NOT apply more than two consecutive sprays.
        1. Follow consecutive applications with two applications of fungicides from a different Mode of Action group(s) before using the product again in the current or following season.

Group 3 (triadimenol) fungicide

        1. Apply before disease becomes established.
        1. Tank mix or alternate with a product that has a different Mode of Action.
        2. Do not apply more than 4 sprays of triadimenol per crop.

Group 7 SDHI (Succinate dehydrogenase inhibitors)

        1. If applying Group 7 fungicides, DO NOT apply more than two consecutive sprays before changing to another group. DO NOT apply more than three Group 7 sprays per season.  If consecutive sprays are used, then use the same number of sprays of an alternative group before using another Group 7, including sprays in consecutive seasons.

Group 13 aza-napthalenes

        1. Apply only as a protectant treatment
        1. DO NOT apply more than three sprays per crop in any one season
        1. DO NOT apply more than two consecutive sprays.

Crop(s):          Tomato

Pest(s):           Target Spot (Early Blight)

Resistance Management Strategy for:

Group 2            (Dicarboximide);

Group 3            (DMI);

Group 7            SDHI (Succinate dehydrogenase inhibitors)

Group 9            (Anilinopyrimidine); and

Group 11          (Quinone outside Inhibitor) fungicides

        1. Limit the use of Group 2, 3, 9 or 11 fungicides to periods when conditions favour disease development.
        1. DO NOT apply more than four Group 2 sprays in one season. Apply no more than two consecutive sprays of a Group 2
        1. DO NOT apply more than six Group 3 sprays in a season. Apply no more than two consecutive sprays of a Group 3 fungicide alone.
        1. If applying Group 7 fungicides, DO NOT apply more than two consecutive sprays before changing to another group. DO NOT apply more than three Group 7 sprays per season.  If consecutive sprays are used, then use the same number of sprays of an alternative group before using another Group 7, including sprays in consecutive seasons.
        1. If three or fewer fungicide sprays for target spot are applied per crop, use only one spray containing a Group 9 If four to six sprays are applied per crop, use a maximum of two sprays containing Group 9 fungicides.  If seven or more sprays are applied per crop, use a maximum of three sprays containing Group 9 fungicides.
        1. Apply no more than two consecutive sprays containing a Group 9 fungicide.
        1. Apply Group 11 fungicides preventively. DO NOT apply more than six sprays, or one third of the total sprays (whichever is lower) from Group 11.  DO NOT apply more than two consecutive sprays of Group 11 fungicides.  If consecutive applications of Group 11 fungicides are used, then they must be followed by at least the same number of applications of fungicide(s) from a different group(s) before a Group 11 fungicide is used again, either in the current or following season.

Crop(s):          Turf

Pest(s):           Various Diseases

Resistance Management Strategy for:

All fungicides

        1. DO NOT apply more than two consecutive sprays of fungicides from the same activity group (other than Group 14, 28, M2, M3, M4 or M5), unless mixed with a protectant fungicide from Group 14, 28, M2, M3, M4 or M5.

Crop(s):          Wheat

Pest(s):           Septoria, Yellow spot, Powdery mildew

Resistance Management Strategy for:

Group 3        (DMI):

Group 7        (SDHI):

Group 11 + 3 (Quinone outside Inhibitor + DMI)- treat as a Group 11; and

Group 11 + 4 (Quinone outside Inhibitor + PAA)- treat as a Group 11

  1. Fungicides should be used as protectant treatments – where no more than 5% leaf area infection evident anywhere in the canopy. In high risk disease environments, integrated management approaches should be used to reduce fungicide resistance risk including the removal of stubble, control of green bridge volunteers and the use of tolerant and resistant varieties.
  2. DO NOT apply more than two applications per growing season of Group 11 or 7 containing products. This includes in-furrow or seed treatments that have activity on foliar diseases. Combinations of in-furrow and seed treatment are counted as one application.
  3. DO NOT  apply consecutive applications of Group 11 containing products. This includes in-furrow i.e. If a Group 11 + 4 fungicide has been used in-furrow at planting, the first foliar fungicide spray must not contain a Group 11 fungicide.
  4. If a solo Group 7 seed treatment has been used with foliar activity (as determined by label claims), the first foliar fungicide applied should not contain a Group 7 fungicide.
  5. If a solo Group 7 fungicide is being applied as a foliar spray it must be mixed with an effective, registered mixing partner.
  6. DO NOT apply more than three applications containing Group 3 fungicides per growing season. This total of three applications includes DMI’s applied as Group 11 + 3 co-formulations and in-furrow or seed treatments that have activity on foliar diseases. Combinations of in furrow and seed treatment are counted as one application.
  7. Minimise use of Group 3 fungicides which are known to have compromised resistance status.

CropLife Australia’s Resistance Management Strategies provide a guide for crop protection product rotation through product groups.  The strategies are a useful tool that supports farmers’ adoption of resistance management.

All crop protection products must be handled and applied strictly as specified on the product label or APVMA permits.  These Resistance Management Strategies do not replace product labels.  They are a guide only and do not endorse particular products, groups of products or cultural methods in terms of their performance.  It is important to check with the Australian regulator’s (APVMA) product database for contemporary information on products and active constituents.  The database can be sourced through www.apvma.gov.au