Australian Pulse Bulletin

Faba bean fungicide guide: 2017 season 

After a reasonable autumn break for sowing crops, conditions in many regions have become cold and dry, with frosty mornings. Some diseases need only limited moisture to infect crops (heavy dew may provide enough moisture), so monitoring needs to be continued through the growth stages of the crop. With good access for ground sprayers this year allowing for high water rates and canopy penetration, timely fungicide application will give the crop the best chance of a high yield.

Foliar fungicide applications will help in the management of faba bean diseases. There are four main fungal diseases of faba and broad bean that require monitoring, chocolate spot (Botrytis fabae and B. cinerea), ascochyta blight (Ascochyta fabae), Cercospora leaf spot (Cercospora zonata) and rust (Uromyces vicia-fabae). Pulse Australia have a number of Minor Use Permits from APVMA in 2017 to help growers manage disease in faba bean crops, and these are shown in the table below along with all the currently registered products.

Decisions need to be made such as when to start the spray program and how often to spray, depending on the varietal resistance, the prevailing weather conditions and the potential yield of the crop.

Fungal disease control is based on protection of plants rather than curing infections. The first fungicide application must be applied as early as necessary to minimise the establishment of the disease. Additional applications are required if the weather conditions favour disease development and spread.

Disease monitoring should be started after crop emergence as cercospora and ascochyta blight can  infect crops in the early stages. If the disease takes hold it can be very difficult to recover crops, as the fungicides have no curative action. Protective sprays may be needed in longer growing seasons until the end of podding. Fungicides remain effective for approximately 10–14 days. Keep in mind that all new growth after fungicide application is unprotected. Timing of fungicide application is critical. These diseases can spread rapidly, so DO NOT DELAY spraying. A spray in advance of a rain front period is desirable. Delaying application until after a rain front will have much reduced efficacy.

The need for repeated fungicide applications depends on the growth stage of the crop, the time since the last fungicide application and the likelihood of further conditions favouring disease development. Unprotected crops can lose over 50% in yield. The numbers of sprays per crop is limited for some products to minimise the development of fungicide resistance. Check the labels for maximum number of sprays permitted. In high disease risk seasons, where multiple fungicide sprays are required, alternate products with different active ingredients.

For more detailed information on disease management: 

• Faba bean: Integrated disease management
• CropPro faba bean disease manual
• Fungicide resistance in grain crops (including pulses)

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  Cercospora (SARDI)

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  Mouldy pods caused by chocolate spot

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  Early indications of chocolate spot

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  Chocolate spot on faba bean leaves and flowers (J Davidson).

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  Ascochyta blight on faba bean leaves (J Davidson).

Fungicide Minor Use Permits for faba bean

• PER84310 Veritas [120 g/L Azoxystrobin And 200 g/L Tebuconazole] / Botrytis grey mould, Ascochyta blight / Current to 30-Nov-2017
• PER84415 Prosaro 420 SC [210 g/L Prothioconazole and210 g/L Tebuconazole] / Ascochyta blight / Current to 30-Nov-2017
• PER84461 Cyprodinil (e.g. Solaris) / Ascochyta blight / Current to 30-Nov-2017
• PER13752 Tebuconazole / Faba Beans & Broad Beans / Cercospora leaf spot & Rust / Current to 30-Jun-2019 

Fungicides registered for use for faba bean

Faba Bean Foliar Fungicide	Trade Name example	Chocolate Spot	Rust	Ascochyta	Cercospora	WHP Harvest
Chlorothalonil 720	CC Barrack 720	1.4-2.3 L/ha	1.4-2.3 L/ha	NR	NR	7 days
Mancozeb 750	Dithane SC	1.7–2.2 L/ha	1.7–2.2 L/ha	1.7–2.2 L/ha	1.7–2.2 L/ha	7 days
Carbendazim	Spin Flo	500 mL/ha	NR	NR	NR	28 days
Procymidone 500	Sumislex 500	500 mL/ha	NR	NR	NR	9 days
Copper	Champ 500DF	1.2 kg/ha	1.2 kg/ha	NR	NR	1 day
Metiram	Polyram DF	1.0–2.2 kg/ha	1.0–2.2 kg/ha	1.0–2.2 kg/ha	1.0–2.2 kg/ha	42 days
Tebuconazole	Folicur SC	NR	Permit 145 mL/ha	NR	Permit 145 mL/ha	21 days
Prothioconazole + Tebuconazole	Prosaro 420 SC	NR	NR	Permit 600–750 ml/ha	NR	21 days
Azoxystrobolin + Tebuconazole	Veritas	Permit 1.0 L/ha	NR	Permit 1.0 L/ha	NR	28 days
Cyprodinal	Solaris 300EC	NR	NR	Permit 500 mL/ha	NR	14 days

Many Minor Use Permits have short term expiry dates (e.g. 30/11/2017) 

NR = Not Registered 

Read the Label As with any chemical application, care should be taken to observe all the label conditions for each product. Some label advice is different for each state or region, so for best results, it is important that this is followed. Many of our pulse crops are exported for human consumption, so market access is dependent on having the product free of chemical residues. Australian has a reputation for providing clean and safe produce so it is vital that this is maintained by using chemicals according to regulations. All permits have label recommendations for use rate and withholding periods (WHP) that must be observed so grain will comply with Maximum Residue Limits (MRL) allowable for market access.

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Last updated: 7 July 2017