Australian Pulse Bulletin

Lentil fungicide guide: 2020 season

• 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 2020

Seasonal conditions have changed markedly in 2020 compared to the last few seasons, especially in the eastern states. After a hot and dry summer in many regions, with bush fires threatening many farming communities, early February and March saw widespread rain events across much of the eastern states coming from north west cloud bands. NSW and Victoria were well above average for this period and meant that dry soils were all recharged ready for the winter cropping seasons. Follow up rain has got the season off to an excellent start. Qld also received reasonable falls in February, but many areas have not had decent follow up falls, so crops are struggling at present. South Australia has had some reasonable rainfall, the south eastern areas were too wet and crop planting was delayed. Overall through SA has crops off to a good start.  In Western Australia the southern and eastern grain belts have again had a dry start, similar to 2019, but recent rainfall has improved prospects. 

These conditions have meant that diseases need to be monitored closely in many regions, particularly in the eastern states. 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)

• 

  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 / 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
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: 13 August 2020