Australian Pulse Bulletin

Field pea fungicide guide: 2022 season

Fungicide sprays will help control some field pea diseases. There are four main fungus diseases in field peas that require monitoring Ascochyta blight (AB; also known as Blackspot), Botrytis grey mould (BGM), Powdery mildew (PM) and Downy mildew (DM). Note that another disease, bacterial blight, cannot be prevented or controlled with foliar fungicide sprays.

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.

Control of foliar fungal disease is based on 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 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 may be quickly defoliated and destroyed by the infection. The choice of fungicide is less important than the timing, but when multiple sprays are required during the season it is critical to rotate different products and modes of action to preserve the effectiveness of all the fungicide choices. Follow this link for advice on maintaining fungicide efficacy for the grain industry. 

Seasonal Conditions in 2022

After several good seasons in 2020 and 2021 that produced record yields in many areas of Australia, rainfall has been variable over summer in many regions. NSW and Queensland have had good rainfall over summer that has given full soil moisture profiles (some paddocks waterlogged). South Australia started with dry conditions for sowing winter crops but have recently received adequate rain to get crops germinated. Victoria had early plant establishment with warm soils and good soil- moisture in most areas, resulting in a higher disease risk. In Western Australia conditions have been very favourable for sowing crops and regular rain events have followed. This season will be favourable for many diseases as we head into spring. Many of these diseases need only limited moisture to infect crops (heavy dew or fog provides enough moisture), so monitoring needs to be continued throughout the season. Later in the season after canopy closure, higher water rates will aid in canopy penetration. Timely fungicide applications ahead of rain events will give the crop the best chance of a high yield. Susceptible crops need continuing fungicide protection for good pod fill so timely application of fungicides by ground sprayers will give the spray coverage required. Growers are recommended to rotate and mix fungicides from different group to minimise the risk of fungicide resistance developing in the pathogen populations. 

Pulse Australia acknowledges the input of the state government pathologists in the preparation of this seasonal guide : Kurt Lindbeck (NSW DPI), Sara Blake (SARDI), Josh Fanning (Vic DPI), Geoff Thomas (WA DPIRD).

For more detailed information on disease management: 

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

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 (M5)	CC Barrack 720	NR	NR	NR	1.1 to 1.8 L/ha Qld, Tas, WA only	7 days
Mancozeb 750 (M3)	Dithane DF	1.7 to 2.5 kg/ha	NR	NR	NR	14 days
Azoxystrobin (Group 11) + Tebuconazole (Group 3)	Veritas	1.0 L/ha	1.0 L/ha	NR	NR	28 days
Azoxystrobin (Group 11) + Tebuconazole (Group 3)	Mirador 625 + Orius 430	150–190 mL + 350–460 mL	150–190 mL + 350–460 mL	NR	NR	28 days
Metiram 700 (M3)	Polyram DF	1.0 to 2.2 kg/ha	1.0 to 2.2 kg/ha	1.0 to 2.2 kg/ha	1.0 to 2.2 kg/ha	42 days
Triadimefon 125 (Group 3)	Genfarm Triadimefon	NR	NR	500 mL/ha NSW, Vic, Tas only	NR	14 days
Zineb 800 (Group Y)	Barmac Zineb	NR	NR	NR	125 g/ha	7 days
Copper Oxychloride (M1)	Champ 500DF	2.5 kg/ha	NR	NR	NR	1 day
Tebuconazole (Group 3)	Folicur SC	NR	NR	145 mL/ha	NR	3 days
Prothioconazole (Group 3) + Bixafen (Group 7)	Aviator XPro	400 to 600 g/ha	NR	NR	NR	35 days
Fludioxonil (Group 12) 150 + Pydiflumetofen (Group 7) 100	Miravis Star	250–500 mL/ha	750–1000 mL/ha	NR	NR	NA – do not apply after end of flowering

Many of the Minor Use Permits have short term expiry dates (e.g. 30/11/2022) 

NR = Not Registered for this disease

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.

Key contacts

Last updated: 26 July 2022