Australian Pulse Bulletin

Field pea fungicide guide: 2017 season

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

Fungicide sprays will help control some field pea diseases. There are four main fungus diseases in field peas that require monitoring — Ascochyta blight (AB), Botrytis grey mould (BGM) and powdery mildew (PM) and downy mildew (DM). Pulse Australia has Minor Use Permits from APVMA to help growers manage disease in field pea 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 value of the crop, especially if it will be harvested for high value human consumption grain markets. Fungal disease control is based on crop protection rather than curing. The first fungicide spray must be applied as early as necessary to minimise the establishment of the disease. Additional sprays are required if the weather conditions favour the disease.

Disease monitoring should be started after crop emergence as AB can infect crops in the early stages. If the disease takes hold it can be impossible to recover crops as the fungicides have only limited curative action. Protective sprays may be needed in longer growing seasons until the end of flowering. Fungicides remain effective for approximately 14–21 days. Keep in mind that all new growth after spraying is unprotected and in periods of rapid growth and good rainfall, usually occurring in early spring, the protection period will reduce to around 10–14 days.

Timing of fungicide sprays is critical. These diseases are spread rapidly, so DO NOT DELAY spraying. A spray in advance of a rainy period is most desirable. Delaying until after a rainy period will be ineffective.

The need for repeated fungicide sprays depends on the amount of unprotected growth, the amount of rainfall since spraying and the likelihood of a further extended wet period. Unprotected crops can lose over 50% in yield. In severe cases the crop may drop all its leaves.

For more detailed information on disease management: 

• Field pea best management guide
• CropPro field pea disease manual
• Fungicide resistance in grain crops (including pulses)

Minor Use Permits for fungicide on field peas

• 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 and 210 g/L Tebuconazole] / Ascochyta blight / Current to 30-Nov-2017

Fungicides registered for disease control in field peas

Field pea Foliar Fungicide	Trade Name example	Ascochyta blight	Botrytis grey mould	Powdery mildew	Downy mildew	WHP Harvest
Chlorothalonil 720	CC Barrack 720	NR	NR	NR	1.1–1.8 L/ha Qld, Tas, WA only	7 days
Mancozeb 750	Dithane DF	1.7–2.5 kg/ha	NR	NR	NR	14 days
Prothioconazole + Tebuconazole	Prosaro 420 SC	Permit 600–750 mL/ha	NR	NR	NR	21 days
Azoxystrobolin + Tebuconazole	Veritas	Permit 1.0 L/ha	Permit 1.0 L/ha	NR	NR	28 days
Metiram700	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
Triadimefon 125	Genfarm Triadimefon	NR	NR	500 mL/ha NSW, Vic, Tas only	NR	14 days
Zineb 800	Barmac Zineb	NR	NR	NR	125 g/ha	7 days
Copper Oxychloride	Champ 500DF	2.5 kg/ha	NR	NR	NR	1 day
Tebuconazole	Folicur SC	NR	NR	145 mL/ha	NR	3 days

Many of the 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