Australian Pulse Bulletin

Lentil fungicide guide: 2019 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 a number of Minor Use Permits from APVMA in place for 2019 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 as lentil are grown for the human consumption market, here and overseas, and market access depends on the strict delivery standards and residue limits. There is no secondary market for lentil if these standards are not met.

Fungal disease control is based on the use of integrated disease management to minimise the injury to crops from plant pathogens. Efficient use of foliar fungicides is based upon the protection of plants rather than curing existing infections. 

There are three critical periods for fungicide spraying decisions on lentil crops for disease.

• First critical period is at 10-14 weeks after emergence (WAE), shortly prior to canopy closure. Early application of fungicide is critical in restricting the early development and spread of BGM. In susceptible varieties, or in districts prone to BGM epidemics, apply a fungicide, irrespective of BGM being present. An application at this stage is the final chance for spray penetration deep into the crop canopy to protect stems.
• Second critical period is at mid flowering/early pod fill (14-16 WAE). If either BGM or AB is present, or weather is conducive to disease, apply a fungicide. The type of fungicide used will be dependent on the variety. Mixtures of foliar fungicides may be required to give control for both diseases in some susceptible lentil varieties.
• Third critical period is at the end of flowering/mid pod fill (16-18 WAE). This is the final growth stage where all pods are formed and protection against AB infection ensures good seed quality is achieved.

 Foliar fungicides remain effective for approximately 10-14 days under ideal conditions. Keep in mind that 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 as diseases can be rapidly spread following rain. Close monitoring for early symptoms will give greater opportunities to minimise disease establishment and spread.

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 severely affected by disease impacting on yield and grain quality particularly in wet springs. 

Seasonal Conditions in 2019

Seasonal conditions have varied widely across Australian cropping areas. After a very hot and dry summer in many regions and variable autumn break for sowing crops, conditions in many regions have become cold and dry, with frosty mornings. In Central Qld conditions have been favourable for crop establishment, but Southern Qld and Northern NSW drought conditions have prevailed since 2017 in many areas, with prospects for winter crops again below average. South Eastern NSW has had some reasonable rainfall, slightly below average, and crops are progressing slowly. In South West NSW though many crops are suffering moisture stress and are well below average. Victoria and South Australia also have average conditions to start but have had reasonable mid-season rainfall to get crops established well. Further rain will be needed in spring to finish these crops. In Western Australia the southern and eastern grain belts have again had a dry start, similar to 2018, but recent rainfall has improved prospects. These conditions have meant that diseases need to be monitored closely in many regions. Monitoring needs to be continued through the different 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.

For more detailed information on disease management: 

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

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  Botrytis affecting a susceptible variety (W. Hawthorne)

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  Botrytis on lentil pod (W. Hawthorne)

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  Ascochyta on lentil leaves (J Davidson).

Minor Use Permits for fungicide on lentils

• PER81533 Custodia / Ascochyta blight, grey mould / Current to 30-Sep-2019
• PER81406 Captan / Ascochyta blight, chocolate spot, grey mould / Current to 30-Sep-2023
• PER82476 Boscalid / Lentils / Sclerotinia Stem Rot (White Mould), Botrytis & Ascochyta Blight / Current to 30-Sept-2020 (All States)
• PER85449 Penflufen / chickpea lentil lupin soybean / Fusarium Wilt / Current to 31-July-2021(seed dressing) (All States)
• PER82273 Chlorothalonil / Lentils / exotic pests and diseases / Current to 31-Mar-2021

Fungicides registered for disease control in lentils

Lentil Foliar Fungicide	Trade Name example	Ascochyta blight	Botrytis grey mould	WHP Harvest
Chlorothalonil 720	CC Barrack 720	1.0 to 2.0 L/ha	1.0 to 2.0 L/ha	14 days
Mancozeb 750	Dithane SC	1.0 to 2.2 L/ha	1.0 to 2.2 L/ha	28 days
Mancozeb 420	Penncozeb SC	1.8 to 3.95 L/ha	NR	28 days
Carbendazim	Spin Flo	NR	500 mL/ha	28 days
Captan 900	CC Captan 900	Permit 1.1 kg/ha	Permit 1.1 kg/ha	14 days
Captan 800	CC Captan 800	Permit 1.25 kg/ha	Permit 1.25 kg/ha	14 days
Azoxystrobolin120 + Tebuconazole 200	Custodia	Permit 1.0 L/ha	Permit 1.0 L/ha	28 days
Boscalid	Filian	NR	Permit 1.2 kg/ha	21 days
Metiram700	Polyram DF	1.0 to 2.2 kg/ha	1.0 to 2.2 kg/ha	42 days
Procymidone	Sumislex	NR	500 mL/ha	21 days
Tebuconazole + Azoxystrobin	Veritas	0.75 to 1.0 L/ha	0.75 to 1.0 L/ha	28 days
Prothioconazole + Bixafen	Aviator XPro	400 to 600 mL/ha	400 to 600 mL/ha	N/A

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: 6 August 2019