Australian Pulse Bulletin

Lentil fungicide guide: 2022 season

Foliar fungicides will help manage the lentil diseases Ascochyta blight (AB) and Botrytis grey mould (BGM), but when to commence a fungicide program and how often to spray, depends on the varietal resistance, weather conditions and the potential yield of the crop.

Pulse Australia have Minor Use Permits from APVMA in place for 2022 to help growers with disease control and these are shown in the table below along with all the current registered products. It is particularly important to observe all the conditions set out in these permits for use in lentils as they are all being grown for the human consumption markets, here and overseas, and market access depends on the strict delivery standards and residue limits. There is no secondary market for lentils if these standards are not met.

Control of foliar fungal disease 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, and how many, are required are determined by environmental conditions favouring the disease.

Fungicides remain effective for approximately 10-28 days under ideal conditions, depending on the actives. Keep in mind that with some chemistries all new growth after spraying is unprotected. Timing of fungicide applications is critical. An application in advance of a rain front provides maximum protection. Delaying application until after a rain front reduces efficacy significantly. Where rotations are close and or inoculum levels are high, a protective fungicide application soon after crop emergence may be required. Close monitoring for early symptoms will be needed to give good disease management.

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. Growers are recommended to rotate and mix fungicides from different group to minimise the risk of fungicide resistance developing in the pathogen populations. Follow this link for advice on maintaining fungicide efficacy for the grain industry.

Seasonal Conditions in 2022

After 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: 

• Lentil: Integrated disease management
• CropPro lentil disease manual
• Fungicide resistance in grain crops (including pulses)

• 

  Botrytis affecting a susceptible variety (W. Hawthorne)

• 

  Botrytis on lentil pod (W. Hawthorne)

• 

  Ascochyta on lentil leaves (J Davidson).

Minor Use Permits for fungicide on lentils

• PER81406 Captan (M4) / Ascochyta blight, chocolate spot, grey mould / Current to 30-Sep-2023
• PER82476 Boscalid / Sclerotinia / Current to 31-May-2027
• PER82273 Chlorothalonil / potential exotic pests and disease / Current to 31-March-2025

Fungicides registered for disease control in lentils

Lentil Foliar Fungicide	Trade Name example	Ascochyta blight	Botrytis grey mould	WHP Harvest
Chlorothalonil 720 (M5)	CC Barrack 720	1.0 to 2.0 L/ha	1.0 to 2.0 L/ha	14 days
Mancozeb 750 (M3)	Dithane SC	1.0 to 2.2 L/ha	1.0 to 2.2 L/ha	28 days
Mancozeb 420 (M3)	Penncozeb SC	1.8 to 3.95 L/ha	NR	28 days
Carbendazim (Group 1)	Spin Flo	NR	500 mL/ha	28 days
Captan 900 (M4)	CC Captan 900	Permit 1.1 kg/ha	Permit 1.1 kg/ha	14 days
Captan 800 (M4)	CC Captan 800	Permit 1.25 kg/ha	Permit 1.25 kg/ha	14 days
Azoxystrobin 120 (Group 11) + Tebuconazole 200 (Group 3)	Veritas	750 mL to 1.0 L/ha	750 mL–1.0 L/ha	28 days
Azoxystrobin 200 (Group 11) + Cyproconazole 80 (Group 3)	Amistar Xtra	400 to 600 mL/ha	400–600 mL/ha	56 days
Prothioconazole 150 (Group 3) + Bixafen  75 (Group 7)	Aviator XPro	400 to 600 mL/ha	400 to 600 mL/ha	N/A Cannot apply after early flowering
Metiram700 (M3)	Polyram DF	1.0 to 2.2 kg/ha	1.0 to 2.2 kg/ha	42 days
Procymidone (Group 2)	Sumislex	NR	500 mL/ha	21 days
Fludioxonil (Group 12) 150 + Pydiflumetofen  (Group 7) 100	Miravis Star	250–500 mL/ha	750–1000 mL/ha	NA – do not apply after first pods

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

NR = Not Registered      NA = Not applicable when used as directed. 

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