Fungicide resistance
Understand how fungicide resistance develops
Manage
disease pressure
Minimise
fungicide use
Engage
with extension
Fungicide resistance is a numbers game – higher disease pressure increases your chances of fungicide resistance developing.
Conducive weather conditions, virulent pathogens with a short life cycle, highly susceptible crop varieties and repeated use of fungicides all contribute to higher risk.
The risk also varies between different chemical groups and fungal pathogens. Specific strategies are recommended for situations considered to carry the highest risk.
To minimise risk, practice The Fungicide Resistance Five.
Advice for growers
Some simple management practices can help you reduce the risk of fungicide resistance occurring in your crops.
Select less susceptible varieties
Sow less-susceptible varieties. Avoid SVS and VS varieties in disease-prone areas. Consult your local crop sowing guide for suitable varieties. Planting less susceptible varieties will reduce disease pressure, and your need for fungicide inputs.
Spray only if necessary and apply strategically
Ensure correct diagnosis to avoid unnecessary fungicide application for non-disease issues such as abiotic stresses or non-fungal diseases. Fungicide use can select for resistance, so it is essential to only spray when the risk or presence of disease warrants it. Spray preventatively, at the first sign of disease, for best effect. Always follow the label and use registered application rates.
Rotate crops and varieties
A dynamic host environment makes it hard for the pathogen to adapt and keeps disease pressure low. Rotate crops to help break the disease cycle and rotate different resistant varieties to slow down pathogen populations overcoming varietal resistance.
Use non-chemical control methods
Remove or reduce stubble loads to minimise carryover of stubble-borne pathogens. Eliminate the green bridge – destroy volunteer plants at least four weeks before sowing. Invest in clean seed and consider earlier or later sowing to help reduce disease pressure.
ROTATE & MIX FUNGICIDE GROUPS
Rotate fungicide groups and use mixtures to reduce fungicide selection pressure. Never apply the same fungicide twice in a row. Avoid using more than one application per growing season of Group 7 SDHI and Group 11 QoI fungicides.
Managing fungicide resistance
Fungicide resistance is a preventable issue that can arise when fungi are overexposed to fungicide actives from the same chemical mode of action (MoA) group. It can become a major constraint to good disease control, especially where no alternative fungicide or effective host-plant resistance is available.
Fungicide resistance is an area-wide, social problem. Spores released by fungicide resistant fungi can spread over large areas in a short time. Misuse of fungicides and poor disease management practices on a single farm can affect everybody in the surrounding region.
The risk is greatest in situations of high disease pressure (influenced by conducive climate and agronomic practices), where there are susceptible crop varieties and virulent pathogens with a short life cycle, and fungicides with a single mode of action are used repeatedly.
Fungicide resistance management. Start with a strong foundation of less susceptible crop varieties, supported by integrated disease management, along with strategic and responsible use of fungicides.
Fungicide resistance evolution. Modified from a CropLife resource. CropLife Australia Fungicide Resistance Management Fact Sheet.
How does fungicide resistance evolve?
Fungicide resistance usually develops following the repeated use of the same fungicide active or other actives within the same fungicide group for disease control. In any fungal population there are likely to be resistant individuals that are less sensitive to fungicides, even before these are applied. If resistant individuals are then repeatedly exposed to the same fungicide group, fungicide selection pressure may increase their frequency in the fungal population.
Continued use of the same fungicide active or other actives from the same fungicide group can result in the selection and subsequent significant build-up of resistant individuals in the fungal population – to the point where that fungicide active, or other actives from the same fungicide group, have reduced efficacy or are no longer effective. In some cases, removal of the selection pressure can result in the fungal population regaining its sensitivity to the fungicide, but this is not always the case.
The risk of developing fungicide resistance varies between different fungicide groups, different fungal pathogens and different environments. Consequently, specific strategies are recommended for those situations considered to carry the highest risk.
Key factors in fungicide resistance
Fungicide resistance is a numbers game – higher disease pressure increases the probability of a pathogen population developing fungicide resistance.
Higher disease pressure means larger pathogen populations. The larger the size of the pathogen population, the higher the likelihood of fungicide-resistant individuals developing within that population due to random mutations. Then, the more fungicide applications that are required to control the disease, the higher the probability of selecting for survival of these fungicide-resistant individuals within the pathogen population.
Higher disease pressure is associated with factors such as:
- favourable weather conditiions for disease development
- sub-optimal agronomic practices, for example, short rotations, varietal susceptibility and planting susceptible varieties in high-risk seasons
- higher intensity agronomic practices, for example, irrigation with higher N inputs, thicker canopies providing more conducive conditions for some leaf diseases
- the presence of green bridges or stubble which can harbour pathogens from the last season
- inherent characteristics of the fungi themselves, for example, rapid life cycle, short latent periods.
The risk of fungicide resistance is greatest in pathogens with short life cycles, where there is a lack of useful resistance in the dominant varieties grown within a region, and when actives within a single fungicide group are used repeatedly.
Fungicide resistance in Australian grains
Current at September 2026. Click on map to view larger image.
Fungicide groups
Different numbers are used to distinguish fungicide groups according to their biochemical action. The numbers were assigned according to the order of introduction to the market. When a pathogen develops resistance to a fungicide, all other fungicide actives within the same fungicide group are often at risk of having reduced sensitivity or resistance develop.
More than 200 fungicides, within 52 fungicide groups, are approved worldwide for the control of fungal pathogens in agriculture. This does not include host-plant defence inducers, chemical multi-site inhibitors, any chemicals with an unknown biochemical action or resistance risk, or biologicals with multiple biochemical actions. Very few fungicide groups are registered for use to combat pathogens of grain crops in Australia, and only a handful of these dominate the market. Having so few fungicide groups available for use increases the risk of fungicide resistance developing, as growers have very few alternatives to rotate with in order to reduce selection pressure.
Dominant fungicide groups registered for diseases of Australian grain crops
Group 3: Azoles/demethylase inhibitors (DMIs)
Common actives:
cyproconazole, epoxiconazole, flutriafol, propiconazole, prothioconazole, tebuconazole, triadimefon.
Registered:
Canola, cereals and pulses. The predominant group, they have been generally cheap and effective against a broad range of diseases in various crops for many years. Commonly used as seed dressing, foliar applications and in-furrow.
Risk of fungicide resistance development:
Moderate
Group 7: Succinate dehydrogenase inhibitors (SDHIs)
Common actives:
bixafen, fluxapyroxad, penflufen.
Registered:
Canola, cereals and pulses. Commonly used as a seed dressing, and as a mixing partner in some foliar formulations. This is a very diverse group and there are distinct differences in disease spectrum and systemic movement of these fungicide actives within plants.
Risk of fungicide resistance development:
Moderate to high
Group 11: Strobilurins/quinone outside inhibitors (QoIs)
Common actives:
azoxystrobin, pyraclostrobin
Registered:
Canola, cereals and pulses. Used as a mixing partner in some foliar and in-furrow formulations. Strobilurins are effective against a broad range of pathogens, and their systemicity varies from local translaminar to upward movement with some actives having vapour activity.
Risk of fungicide resistance development:
High
Group 3: Azoles/demethylase inhibitors (DMIs)
Common actives:
cyproconazole, epoxiconazole, flutriafol, propiconazole, prothioconazole, tebuconazole, triadimefon.
Registered:
Canola, cereals and pulses. The predominant group, they have been generally cheap and effective against a broad range of diseases in various crops for many years. Commonly used as seed dressing, foliar applications and in-furrow.
Risk of fungicide resistance development:
Moderate
Group 7: Succinate dehydrogenase inhibitors (SDHIs)
Common actives:
bixafen, fluxapyroxad, penflufen.
Registered:
Canola, cereals and pulses. Commonly used as a seed dressing, and as a mixing partner in some foliar formulations. This is a very diverse group and there are distinct differences in disease spectrum and systemic movement of these fungicide actives within plants.
Risk of fungicide resistance development:
Moderate to high
Group 11: Strobilurins/quinone outside inhibitors (QoIs)
Common actives:
azoxystrobin, pyraclostrobin
Registered:
Canola, cereals and pulses. Used as a mixing partner in some foliar and in-furrow formulations. Strobilurins are effective against a broad range of pathogens, and their systemicity varies from local translaminar to upward movement with some actives having vapour activity.
Risk of fungicide resistance development:
High
Other registered MoAs in Australia
Note: Fungicides are registered on a state/territory, crop, target pathogen, formulation and application rate basis. Current information on registered fungicides and their use can be found on the APVMA website at apvma.gov.au. Risk of resistance development indicated above is based on global experience and assessments by the Fungicide Resistance Action Committee (FRAC).
Fungicide resistance in Australia
Fungicide resistance occurs when a previously effective fungicide fails to control a disease, despite being applied correctly. It is a preventable issue that can arise when fungi are exposed repeatedly to the same fungicide or fungicide actives from the same fungicide group. It can become a major constraint to disease control, especially where no alternative fungicide or effective host-plant resistance is available.
As fungicide use continues, and survey and detection techniques become more sophisticated and widely adopted across regions, the industry can expect more cases of resistance and reduced sensitivity.
Fungicide resistance terminology
Sensitivity
Sensitivity in fungal pathogens refers to the susceptibility of a fungus to a particular fungicide. A sensitive pathogen is effectively controlled or inhibited by the fungicide at recommended doses, meaning the fungicide can prevent the growth and spread of the pathogen.
Reduced sensitivity
Fungi are considered to have reduced sensitivity to a fungicide when the application does not work optimally but does not completely fail. This occurs when the fungicide provides less control of the target fungal pathogen in the field than it once did, even when applied at recommended rates. In the field, an increased frequency of individuals with reduced sensitivity within the fungal population indicates that a growing portion is less affected by the fungicide. This change can be a precursor to resistance and must be confirmed through monitoring and specialised laboratory testing.
Resistance
Resistance occurs when the fungicide fails to provide an acceptable level of control of the target pathogen in the field, even at maximum label rates. A high frequency of resistant individuals within the fungal population indicates that a significant portion is unaffected by the fungicide, rendering the application ineffective. Confirmation of resistance requires laboratory testing and clear evidence of field failure.
Laboratory detection
A laboratory detection relates to measurable differences of a fungal isolate’s sensitivity to a fungicide in scientifically recognised in vitro tests, or the detection of a mutation in a fungal isolate that may result in fungicide resistance. These changes can often be detected in the laboratory before any loss of fungicide efficacy is detected in the field. Laboratory detections are used to confirm reports of field resistance or reduced sensitivity, or to indicate the potential for resistance or reduced sensitivity to develop.
Barley
Fungicides – current field performance quick guide
Only diseases of pathogens known to have fungicide resistance or reduced sensitivity in Australia are listed.
Use fungicides strategically for yield improvement. Always consider your local environmental conditions and the susceptibility of the crop variety to the target pathogen before fungicide application. Fewer fungicide applications will likely be required for less-conducive environmental conditions using less-susceptible varieties.
Disclaimers:
Fungicide performance is current at January 2026 and can change if fungicide resistance spreads. Resistance can spread from local to regional levels, and the status of fungicide actives within each fungicide group can vary by location. Farm-level or regional field performance may vary. Check PRIM (prim.ccdm.com.au) for up-to-date information in your area. Not all fungicide actives within a fungicide group are registered for use on the target pathogens indicated in each region. It is the responsibility of growers and advisers to ensure that the fungicide is registered, or that permits are current, for their target pathogen, crop and region. Current information on registered and permitted fungicides can be found on the APVMA website (apvma.gov.au).
| Group 3 (DMI) | Group 7 (SDHI) | Group 11 (QoI) | ||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| e.g. epoxiconazole, flutriafol, propiconazole, tebuconazole | e.g. fluxapyroxad, bixafen | e.g. azoxystrobin, pyraclostrobin | ||||||||||||||||
| NSW | Qld | SA | Tas | Vic | WA | NSW | Qld | SA | Tas | Vic | WA | NSW | Qld | SA | Tas | Vic | WA | |
| Barley powdery mildew | ||||||||||||||||||
| Net form net blotch | ||||||||||||||||||
| Spot form net blotch | ||||||||||||||||||
| Barley leaf rust | ||||||||||||||||||
Barley powdery mildew
Caused by Blumeria hordei
RESISTANCE STATUS
Barley powdery mildew is an important disease of barley, especially in the western and northern regions. It is also potentially very damaging in the southern region in conducive seasons. Severe infections can occur in winter during both early and later stages of crop growth and can cause significant yield loss in crops with high yield potential.
Barley powdery mildew is typically favoured by susceptible hosts, mild and humid weather (15° C to 22° C, relative humidity (RH) > 70%), dense crop canopies, higher nitrogen levels, good soil moisture profiles, and extended periods of humid and damp canopies. The pathogen survives on barley stubble and volunteer barley plants, from which spores can spread by wind.
Note that barley and wheat powdery mildew are caused by different fungal species.
Net form net blotch (NFNB)
Caused by Pyrenophora teres f. teres
RESISTANCE STATUS
Net form net blotch (NFNB) is an important disease of barley across all growing regions, especially in medium to high-rainfall zones of southern Australia and WA. It is particularly damaging in wetter years, in systems with high inclusion of susceptible barley in rotations and where barley is sown into barley stubble. Severe infections can cause 20 to 50% yield loss and significant reduction in grain quality.
NFNB is typically favoured by susceptible hosts, early sowing, mild weather (15° C to 25° C) and extended periods of leaf wetness. It survives between seasons on stubble, volunteer plants and seed.
Spot form net blotch (SFNB)
Caused by Pyrenophora teres f. maculata
RESISTANCE STATUS
Spot form net blotch (SFNB) is an important disease of barley across all growing regions. It is particularly damaging in wetter years in the southern regions, in early sown crops, in systems where barley is sown into barley stubble. Severe infections can cause 10 to 45% yield loss and significant reduction in grain quality.
SFNB is typically favoured by susceptible hosts, mild weather (15° C to 25° C) and extended periods of leaf wetness. It survives between seasons on stubble.
Barley leaf rust
Caused by Puccinia hordei
RESISTANCE STATUS
The pathogenic fungus that causes barley leaf rust is of concern as it can spread rapidly over vast distances. Rust-infected crops produce billions of microscopic spores that are highly adapted to wind dispersal. Early infections of leaf rust can result in significant yield losses. Infection is favoured by moist conditions with temperatures around 15° C to 20° C. Crops sown early when nights are still warm are often more severely infected.
Unlike other cereal rust pathogens, in some parts of Australia the barley leaf rust pathogen can survive between seasons by infecting its alternate host, the winter-flowering bulb Star of Bethlehem (Ornithogalum umbellatum). Sowing barley into paddocks where Star of Bethlehem is present is not recommended. This plant is a common weed in some areas of the Yorke Peninsula in SA and in Victoria, Tasmania and WA.
Wheat
Fungicides – current field performance quick guide
Only diseases of pathogens with known mutations conferring fungicide resistance or reduced sensitivity in Australia are listed.
Use fungicides strategically for yield improvement. Always consider your local environmental conditions and the susceptibility of the crop variety to the target pathogen before fungicide application. Fewer fungicide applications will likely be required for less-conducive environmental conditions using less-susceptible varieties.
Disclaimers:
Fungicide performance is current at January 2026 and can change if fungicide resistance spreads. Resistance can spread from local to regional levels, and the status of fungicide actives within each fungicide group can vary by location. Farm-level or regional field performance may vary. Check PRIM (prim.ccdm.com.au) for up-to-date information in your area. Not all fungicide actives within a fungicide group are registered for use on the target pathogens indicated in each region. It is the responsibility of growers and advisers to ensure that the fungicide is registered, or that permits are current, for their target pathogen, crop and region. Current information on registered and permitted fungicides can be found on the APVMA website (apvma.gov.au).
| Group 3 (DMI) | Group 7 (SDHI) | Group 11 (QoI) | ||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| e.g. epoxiconazole, flutriafol, propiconazole, tebuconazole | e.g. fluxapyroxad, bixafen | e.g. azoxystrobin, pyraclostrobin | ||||||||||||||||
| NSW | Qld | SA | Tas | Vic | WA | NSW | Qld | SA | Tas | Vic | WA | NSW | Qld | SA | Tas | Vic | WA | |
|
Wheat powdery mildew |
||||||||||||||||||
|
Septoria tritici blotch |
||||||||||||||||||
Wheat powdery mildew
Caused by Blumeria graminis
RESISTANCE STATUS
Wheat powdery mildew is a sporadic and important disease in years with conducive conditions, especially in the southern region. Wheat powdery mildew is typically favoured by susceptible hosts, early sowing, mild and humid weather (15°C to 22°C, relative humidity > 70%), dense crop canopies, good soil moisture profiles, higher nitrogen status and extended periods of humid and damp canopies.
It is spread predominantly via wind-borne spores, and survives on stubble and volunteer plants.
Note that wheat and barley powdery mildew are caused by different sub-species, so are crop specific.
Septoria tritici blotch (STB)
Caused by Zymoseptoria tritici
RESISTANCE STATUS
Septoria tritici blotch (STB) is an important disease of wheat, particularly in high rainfall areas of the southern region.
It is more common in early sown crops and in wet springs, and is typically favoured by stubble retention, susceptible cultivars, cool, wet weather (15–20°C, relative humidity > 70%), dense crop canopies and extended periods of leaf wetness or dew.
It can cause up to 20% yield loss annually, and much more (> 50%) in conducive years. It survives on stubble.
Canola
Fungicides – current field performance quick guide
Only diseases of pathogens with known mutations conferring fungicide resistance or reduced sensitivity in Australia are listed.
Use fungicides strategically for yield improvement. Always consider your local environmental conditions and the susceptibility of the crop variety to the target pathogen before fungicide application. Fewer fungicide applications will likely be required for less-conducive environmental conditions using less-susceptible varieties.
Disclaimers:
Fungicide performance is current at January 2026 and can change if fungicide resistance spreads. Resistance can spread from local to regional levels, and the status of fungicide actives within each fungicide group can vary by location. Farm-level or regional field performance may vary. Check PRIM (prim.ccdm.com.au) for up-to-date information in your area. Not all fungicide actives within a fungicide group are registered for use on the target pathogens indicated in each region. It is the responsibility of growers and advisers to ensure that the fungicide is registered, or that permits are current, for their target pathogen, crop and region. Current information on registered and permitted fungicides can be found on the APVMA website (apvma.gov.au).
| Group 3 (DMI) | Group 7 (SDHI) | Group 11 (QoI) | ||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| e.g. fluquinconazole, flutriafol, tebuconazole | e.g. bixafen | e.g. azoxystrobin | ||||||||||||||||
| NSW | Qld | SA | Tas | Vic | WA | NSW | Qld | SA | Tas | Vic | WA | NSW | Qld | SA | Tas | Vic | WA | |
| Blackleg | ||||||||||||||||||
| Group 12 | ||||||
|---|---|---|---|---|---|---|
| e.g. fludioxonil, phenylpyrrole | ||||||
| NSW | Qld | SA | Tas | Vic | WA | |
| Blackleg | ||||||
Blackleg
Caused by Leptosphaeria maculans
RESISTANCE STATUS
Blackleg is the most important and costly disease of canola in Australia and is widespread in all growing regions. Blackleg is typically favoured by high-intensity canola plantings, high annual rainfall (> 500 mm), high total rainfall in the three months prior to sowing (March-May; > 100 mm), susceptible cultivars, and extended periods of leaf wetness (> 48 h). It can cause yield losses of 50 to 90% in conducive years. It is a stubble-borne disease and spores are spread from stubble remaining from the previous season.
When seedlings are infected, the disease progresses from cotyledons and stems into the crown of the plant causing damage within the plant’s vascular system, forming crown canker. Infection later in the season, referred to as ‘upper canopy infection’, results in upper stem lesions, infected branches, flower infection and abortion of complete flower heads, leading to missing pods.
Consult the Blackleg management guide or BlacklegCM app to determine individual paddock risk for blackleg.
Pulses
Fungicides – current field performance quick guide
Only diseases of pathogens with known mutations conferring fungicide resistance or reduced sensitivity in Australia are listed.
Use fungicides strategically for yield improvement. Always consider your local environmental conditions and the susceptibility of the crop variety to the target pathogen before fungicide application. Fewer fungicide applications will likely be required for less-conducive environmental conditions using less-susceptible varieties. A variety of fungicide groups are registered for control of some or all pulse diseases, including Groups 1, 2, 3, 5, 7, 11, 12, 13 and the multi-site groups M3 and M5. Currently there has been no detection of mutations or reduction in fungicide efficacy in vitro associated with reduced sensitivity or resistance to any other fungicide group in Australia, other than those listed in the table.
Disclaimers:
Fungicide performance is current at January 2026 and can change if fungicide resistance spreads. Resistance can spread from local to regional levels, and the status of fungicide actives within each fungicide group can vary by location. Farm-level or regional field performance may vary. Check PRIM (prim.ccdm.com.au) for up-to-date information in your area. Not all fungicide actives within a fungicide group are registered for use on the target pathogens indicated in each region. It is the responsibility of growers and advisers to ensure that the fungicide is registered, or that permits are current, for their target pathogen, crop and region. Current information on registered and permitted fungicides can be found on the APVMA website (apvma.gov.au).
| Group 3 (DMI) | Group 7 (SDHI) | Group 11 (QoI) | ||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| e.g. tebuconazole | e.g. bixafen | e.g. azoxystrobin | ||||||||||||||||
| NSW | Qld | SA | Tas | Vic | WA | NSW | Qld | SA | Tas | Vic | WA | NSW | Qld | SA | Tas | Vic | WA | |
|
Ascochyta blight of lentils |
||||||||||||||||||
|
Botrytis grey mould of chickpea |
||||||||||||||||||
|
Mungbean powdery mildew |
NR | NR | NR | NR | NR | NR | ||||||||||||
| Group 1 (MBC) | ||||||
|---|---|---|---|---|---|---|
| e.g. thiabendazole to carbendazim | ||||||
| NSW | Qld | SA | Tas | Vic | WA | |
| Ascochyta blight of lentils | ||||||
| Botrytis grey mould of chickpea | ||||||
| Mungbean powdery mildew | NR | NR | NR | NR | NR | NR |
Ascochyta blight of lentils
Caused by Ascochyta lentis (syn: Didymella lentis)
RESISTANCE STATUS
Ascochyta blight is an important disease of lentils in Australia, especially in the key growing areas of the southern region. It can affect all above-ground plant parts including leaves, stems and pods, and is often inconspicuous, relying on close inspection to detect it. Ascochyta blight is favoured by prolonged cool and wet conditions (5° C to 15° C) early in the growing season, and heavy rainfall later in the season to establish pod and seed infections.
Unprotected crops can suffer more than 50% yield loss, and in severe cases the crop may drop all of its leaves. It is spread typically via rain splash surviving on stubble and self-sown plants, and from infected seed.
Botrytis grey mould of chickpeas
Caused by Botrytis cinerea
RESISTANCE STATUS
Botrytis grey mould is a serious disease of chickpea, especially in the northern growing regions. It has a wide host range, across a number of horticultural crops and multiple pulse species. This wide host range, combined with its capacity to survive on dead plant material, means inoculum is rarely limiting and infections can proceed quickly when conditions are favourable.
Botrytis grey mould is typically favoured by crops with thick, closed canopies that provide conducive temperature and humidity conditions (20° C to 25° C, RH > 90%) for infection. Yield reductions can result via seedling loss due to seedborne root rot, and infection of stems, flowers, pods and leaves throughout the season. Yield loss in unprotected crops can be as high as 10 to 25% under conducive conditions and can cause complete crop failure in extreme cases. It is spread predominantly via airborne spores, infected alternate hosts, and contaminated seed, soil and stubble.
Mungbean powdery mildew
Caused by Podosphaera xanthii and Erysiphe vignae
RESISTANCE STATUS
Powdery mildew is the most common disease of mungbean in all areas of production across Australia. All mungbean cultivars grown in Australia have some degree of susceptibility to powdery mildew.
The causal agents infect all green tissues of the crop, and especially the leaves and stems. The pathogens are spread solely by short-lived, airborne spores. The host ranges of the two fungal species that cause powdery mildew on mungbean are not known, but it is likely that they survive on alternative hosts, including weeds, and on volunteer mungbean plants.
The disease is favoured by milder temperatures (22° C to 26° C) and higher humidity values; therefore, it mostly develops at the end of the summer season. The most damaging epidemics are those that start before flowering. Therefore, planting mungbean early in the summer season may help reduce the economic losses caused by powdery mildew. Disease can cause up to 40% yield loss if the epidemic starts before flowering, the environmental conditions are conducive to the disease, and if no management strategies are applied. The disease may also have an impact on crop desiccation.