Some of Australia’s major growers of citrus fruit are demanding urgent action in the Northern Territory to prevent a disease outbreak that is spreading south and west from Darwin, threatening to ruin the $750 million industry. The growers want all citrus trees in the restricted area and control areas in the NT and WA destroyed immediately (with owner reimbursement and compensation). This might save the 28,000 ha of trees in the rest of the country that may be in the path of the outbreak of Asiatic citrus canker.
The latest outbreak has been confirmed at several plant nursery sites in and around Darwin, as well as in Kununurra in WA. In the last 48 hours, there have been reports the infestation has moved south, past Adelaide River and into Katherine, more than 300 km from Darwin.
Asiatic citrus canker is a contagious bacterial disease that causes unsightly lesions on fruit, its leaves and stems, reducing their appeal to the markets. Trees infected with the disease may suffer from low vigour and a reduction in fruit quality and quantity. Canker affects limes, lemons, citron, mandarins, oranges and grapefruit.
Australia has had seven outbreaks of citrus canker in the last 100 years and each time it has been eradicated. In 2004, an outbreak of citrus canker at one property near Emerald in Queensland eventually resulted in all citrus trees within a 50-km radius being destroyed as a precautionary measure. This growing district had 500,000 trees. The disease was eradicated and, after two years, orchards were replanted but the economic cost to some individual growers was in the tens of millions of dollars.
That is why today growers are alarmed at the potential of the latest NT nursery outbreak to once again decimate the industry. They want the same action taken now as in Emerald in 2004; destroy all host plants in the Northern Territory.
Yet, so far it has already taken plant health authorities four weeks to confirm the NT outbreak, twice as long as in 2004. According to some growers there is a code of silence in place that involves plant health authorities and even the industry’s peak body, Citrus Australia, because it cannot or will not reveal to growers the full impact of the outbreak. Citrus Australia is effectively gagged through its membership of Plant Health Australia’s Emergency Plant Pest Response Deed.
Citrus grower Craig Pressler had 200,000 of his own trees destroyed in 2004 when canker was found in central Queensland. He says destroying the plants was the only way to stop the spread of canker.
Greg Owens, CEO of the Northern Territory Farmers Association, reacted to Pressler’s idea of removing all plants in the affected area: "We are working closely with the government on how to find out where the affected trees have gone and how we manage that. As for pulling trees in the Northern Territory, it's a bit premature to make that decision yet. He [Pressler] is worried about the wet season, which for us is about five to six months away. It's an incredibly serious disease, so I wouldn't call that an overreaction. At the moment we might disagree on methods, but the one thing that we do agree on is that this disease needs to be eradicated - and it has been done before, in Queensland and the Northern Territory. The longer discussion that we might have is on the methods that we actually achieve that. There is no disagreement that our aim is to eradicate the disease, but at the moment we will continue to work with our quarantine guys on how we do it."
Owens realises this situation is affecting the NT citrus season. "It is quite serious for our growers. We tend to, in this area, have a predominance of small growers that will be producing three main products: Tahitian limes, pomelo, which is a large grapefruit, and also Kaffir lime leaves. Those guys are quite specialised and this is quite peak period for them and it really tough for those guys because while there is agreed international protocols and the states have agreed to for moving fruit back into the domestic market, there's nothing for kaffir lime leaf growers yet. That is a really serious issue we need to get on top of so they can get back in the market. So they are hurting at the moment and we are doing what we can about it."
"This is another one of a serious biosecurity incursions that have come into different states and territories. We cannot urge people enough to be really conscious that everyone in Australia needs to take biosecurity to heart and protect our industries across the continent and into Tasmania. It can cripple industries and we just urge people to be biosecurity aware if they are travelling overseas or interstate and check that they check all the regulations, on moving any plant or animal material before they do so."
Citrus is the nation’s largest fresh fruit export industry. In 2017 export earnings rose 41 per cent to $462 million with China the major market. Australia’s major production regions are in the Riverland, the Murray Valley, the Riverina and the Central Burnett region in Queensland as well as some plantings in WA, inland and coastal NSW and the Northern Territory.