Disease symptoms

The most common symptoms of lupin anthracnose

• Bent and twisted stems (known as shepherd's crook) and pods
• Complete pod loss
• Malformed, scarred seed
• Lesions on plants.

The cooperation of growers has helped to successfully eradicate lupin anthracnose from NSW after detection of the disease three years ago.

Unusual disease symptoms in lupin crops were reported to the NSW Department of Primary Industries (DPI) in October 2016. DPI pulse and oilseed pathologist Dr Kurt Lindbeck confirmed lupin anthracnose as the cause.

The disease is caused by the fungal pathogen Colletotrichum lupini and results in distinct lesions on plants and bent, twisted stems and pods, followed by complete pod loss and malformed, scarred seed. Very distinct bright orange/pink spore masses form within lesions.

The most obvious symptom in lupins is the bending and twisting of stems, known as 'shepherd's crook', which is particularly noticeable when the crop is flowering and developing pods.

The disease affects all lupin species but is particularly devastating to albus lupin and as such has the potential to dramatically change the management and profitability of the crop in NSW.

Anthracnose of lupin is regarded as the most damaging fungal disease of lupins worldwide, and has spread globally since the 1930s via movement of infected seed. The eastern states of Australia are the last lupin-producing regions globally not to have the disease present.

Fortunately, the spread of the disease was restricted in 2016 to a small number of properties in the Riverina, so NSW DPI and Local Land Services were able to successfully implement a response plan to eradicate it.

With the cooperation of growers, the infected crops were managed on a case-by-case basis, which included restricting access to infected lupin crops and preventing the planting of lupins in a defined management zone.

Ongoing surveillance of commercial lupin crops for the disease continued across NSW for the next two seasons. In June 2019, NSW was declared free of the disease, allowing planting restrictions to be lifted as no recurrence of the disease had been detected.

While the source of the NSW outbreak in 2016 remains uncertain, the successful eradication response by NSW DPI and Local Land Services is a great example of how early reporting of unusual symptoms can help protect an industry.

The incursion of lupin anthracnose into NSW should also remind growers to be vigilant about farm biosecurity, especially when it comes to sourcing planting seed and managing the movement of machinery and people on properties.

Lupin anthracnose can spread between paddocks via contaminated vehicles and machinery, people, clothing and animals. Infected stubble can also be a source of new infection. The pathogen's main survival between seasons is on seed.

Lupin anthracnose is an established disease in Western Australia and South Australia, but had not been found in commercial lupin crops in NSW prior to this incident. Restrictions have been in place since 1996 to stop whole lupin seed and plant material entering NSW from either of these states.

Dr Lindbeck advises lupin growers to put in place a management plan to prevent the possible establishment and spread of the disease in eastern Australia, involving:

• treating seed with a fungicide before planting (where inoculating the seed, do this just prior to planting to maximise rhizobium survival);
• planting lupins at least 500 metres away from last year's stubble;
• controlling volunteer lupins over summer to prevent possible disease build-up; and
• controlling people and machinery movements into and out of lupin crops.

If you spot anything unusual, call the Exotic Plant Pest Hotline on 1800 084 881.

Note: Anthracnose surveillance has been supported by the Grains Agronomy & Pathology Partnership: a strategic partnership between GRDC and NSW DPI.