CITRUS GREENING DISEASE

The Hon. J.S.L. DAWKINS (15:11): I seek leave to make a brief explanation before asking the Minister for Agriculture, Food and Fisheries a question regarding the government's response to the threat of citrus greening disease.

Leave granted.

The Hon. J.S.L. DAWKINS: Citrus greening, also known as huanglongbing (or HLB), is one of the worst biological problems facing the citrus industry worldwide. It is a bacterial disease which has no cure, meaning any infected citrus trees must be removed and replaced, causing massive income and job losses for commercial plantations. Citrus greening has been discovered literally on our national doorstep in countries as close as Indonesia and Papua New Guinea.

Through the illegal importation and planting or grafting of trees from infected areas overseas, citrus greening can spread to entire orchards, turning the canopy of trees yellow, mottling their leaves and eventually causing them to die. The importance of ensuring this disease is quarantined outside Australia's borders cannot be overestimated, particularly for the welfare of the South Australian citrus industry. My questions to the minister are:

1. What strategy does PIRSA have to deal with the potential threat of citrus greening to citrus crops in South Australia?

2. Is the state government working with the Australian Quarantine and Inspection Service to mitigate as far as practicable the risks posed by citrus greening to South Australia's significant citrus industry?

The Hon. G.E. GAGO (Minister for Agriculture, Food and Fisheries, Minister for Forests, Minister for Regional Development, Minister for the Status of Women, Minister for State/Local Government Relations) (15:11): I thank the honourable member for his important question. There are many biosecurity threats or potential threats to our primary industries, and this is one which potentially could impact on our citrus industry, which is why our biosecurity protection and monitoring systems are so important to this state.

In relation to this particular pest, HLB, I am advised there are three recognised strains of the pathogen—an Asian strain, an American strain and an African strain. The bacterium is spread between trees by sucking insects or by grafting. Current evidence suggests that all species and varieties of citrus are likely to be susceptible to HLB but to varying degrees. A pest risk review by Plant Health Australia and Citrus Australia concluded that HLB could cause a significant and potentially unrecoverable decline in the Australian citrus industry over 10 to 20 years.

The effects of the disease on productivity are often severe, particularly for sweet oranges, mandarins and the like. The Australian government has implemented quarantine arrangements to minimise the risk that the disease may be introduced into Australia. Biosecurity SA is actively monitoring for HLB as part of their national plant health surveillance program, and in the event of an outbreak in Australia, surveillance and early detection will be critical to any eradication effort.

HLB is classified as an emergency plant pest under the Emergency Plant Pest Response Deed. The disease is category 2 which means that the cost of eradication would be shared as 80 per cent by governments and 20 per cent by industry. Citrus Australia has put a research proposal to Plant Health Australia to look at prevention and eradication measures should the disease become established in Australia. The key issue in the proposal is establishing facilities to maintain a bud wood scheme to supply growers with disease-free citrus varieties in the event of an outbreak, and obviously we continue to remind growers to be vigilant in monitoring their orchards for symptoms of HLB.