Olive Quick Decline Syndrome

December 16, 2016

times

Friday, 16th December, 2016

Olive Quick Decline Syndrome

Alfred E Baldacchino

Mid-October 2013, saw Xylella fastidiosa, the olive quick decline syndrome (OQDS) recorded in Italy: its first record for Europe. By April 2015 it had infected up to a million olive trees, many of them century-old, in the southern region of Apulia. This invasive disease is believed to have been introduced by ornamental plants from Costa Rica, where it is also causing havoc.

By July 2015 it quickly spread to Corsica, in municipalities of Nice, and Mandelieu-la-Napoule and by late October in Alpes-Maritimes in France. August 2016 saw it in Germany infecting oleander plants.

November 2016 found OQDS in the Spanish island of Mallorca, in a garden centre on three cherry trees and an oleander.

OQDS is regarded as the most harmful plant pathogenic bacteria in the world. It infects grapevines, peaches, citrus, oak, sycamore, and many other trees and ornamental plants, such as spurge, lavender and rosemary. No cure has yet been found for such disease, as the European Food Safety Organisation has warned.

European and Mediterranean Plant Protection Organisation (EPPO) had since 1981 listed it on its A1 list of pests recommended for regulation as quarantine pests, regarding it as representing a very serious threat for the EPPO region

effect-of-x-f

Symptoms of OQDS, regarded as the most harmful plant pathogenic bacteria in the world.

Across Europe, 359 plant species have been identified as susceptible to Xylella. Many of these species show no symptoms of the disease, and provide a reservoir for reinfection of other plants, thus making Xylella difficult to control and making phytosanitary certificates  useless

This bacterium thrives in the water-conducting vessels (xylem) of plants. It invades these vessels and blocks the transport of water and other soluble mineral nutrients. This leads to the drying, scorching, wilting of the foliage, and eventually the collapse and death of the tree.

spittlebug

Spittlebugs – serves as carriers of OQDS

It spreads with the help of insects such as leafhoppers and spittlebugs, which feed on the plant xylem. These insects do not fly long distances, but can be helped by the wind, by other animals, and by vehicular transport.

Spain and France were deeply concerned when Xylella was recorded for the first time in 2013. Their production of olive oil and wine is under a great threat. The matter was also raised at European Union level.

Italy is heavily affected, considering that the only method to date to control such disease is by eradication of the infected million olive trees. These contribute to 40 per cent of the olive oil produced in Italy. Besides the economic loss, the social and ecological impacts are beyond any estimate.

effect-of-x-f-2

Olive trees which succumbed to OQDS. Not that we really need Xylella to reduce our olive trees to such a state. The sight of the 60 olive trees on Malta University campus were similarly aesthetically reduced and paid for by University funds. Perhaps the University’s educational pro-active vision wanted to show the people a picture of things to come if Xylella succeeds in being imported in Malta. The only difference would be that they will give up their  ghost for ever.  

Malta is blessed that it is an island surrounded by an expanse of sea that makes it impossible for these xylem-feeding insects to arrive naturally. But… it seems that we never learn.

butchered tree 7

Pruned olive trees which once enhanced the campus of the University of Malta. A mis-management exercise of the highest grade.

Palm trees were imported for landscaping purposes from areas known to be infected by the Asian red palm weevil. More than 5,000 palm trees have been lost to date. Timber introduced the African long-horned mulberry beetle, which besides killing most of the mulberry trees in the islands, now has turned its attention to the white mulberry, carob and fig tree.

Imported geraniums by garden centres have also helped to introduce the geranium bronze butterfly from South Africa. All of these have been introduced by trees and plants carrying a phytosanitary certificate from the country of origin, to confirm that they were all disease free. How many imported tomato seedlings accompanied by a phytosanitary certificate, introduced the South American tomato moth (Tuta absoluta)?

Trees and other plants mainly, for landscaping and ornamental purposes, are still being imported from countries which are infected with this OQDS.

The Ministry for the Environment is responsible to ensure that such invasive species and other pathogens are not introduced in Malta, both through the Environment and Resource Authority, and also through its Parliamentary Secretary responsible for the Department of Agriculture. Once there was a renowned experimental farm at Għammieri, which today is more concerned with domestic dogs, cats, and birds.

A very good animation video has been produced by the Plant Health Department. Very good. What is needed now is urgent action.

Environmental responsibilities are far from being helped by the Ministry of Landscaping. Doors are flung wide open for exotic species to be planted in ‘landscaping’ projects, paid out of public funds, administered through an €8 million yearly budget, according to a secret agreement which, despite the Commissioner for Data Protection’s ruling, is still being withheld.

If Xylella were to make a foothold on this island, the price that society and the environment will have to pay is beyond any imagination

Those handful of pro-business politicians and their acolytes might ask if they are expected to stop the importation of exotic species. The question is whether such politicians are worried, not only for the young developing olive oil industry in Malta which is trying hard to acquire an EU/EC Declaration of Conformity (DOC) for CE Marking, but also for the wine and citrus industry. And naturally the islands ecosystem which if, God forbid, Xylella were to make a foothold on this island, the price that society and the environment will have to pay is beyond any imagination.

Prevention is better than cure, especially when there is no cure at all. That would be the day when one can honestly boast of a sound environmental policy. From experience, political action in this regard will only be considered when the social, economic and environmental fabric have bit the dust, or as it is said, when all the horses have bolted.

aebaldacchino@gmail.com

Alfred Baldacchino is a former assistant director of the Malta Environment and Planning Authority’s environment directorate.

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Valley flora being slowly choked by invasive plant

March 9, 2013

times

Saturday, March 9, 2013 by

Juan Ameen

Valley flora being slowly choked by invasive plant

A biodiversity expert has expressed concern that the flora of Wied Babu in Żurrieq, a protected Natura 2000 site, is slowly being choked by an invasive plant from the Americas.

Alfred Baldacchino said the biodiversity at Wied Babu was “under great negative impact” by Cardiosperum grandiflorum, also known as Showy Balloon Vine or Love in a Puff.

2. Cardiospermum grandiflorum spreading at Wied Babu

1. Cardiospermum grandiflorum spreading at Wied Babu

The plant has already had a negative impact on carob trees, Mediterranean Heather and brambles at the mouth of the valley and “is rapidly advancing towards a healthy stand of protected buckthorn, destroying everything in its wake”, Mr Baldacchino said.

He pointed out that the plant was also spreading at the other end of the valley – one of the richest environments for Maltese indigenous flora.

3. Cardiospermum grandiflorum suffocating carob trees and brmable

2. Cardiospermum grandiflorum suffocating carob trees and bramable

The plant originates from the tropical regions of the Americas, especially Brazil and eastern Argentina, and has been introduced outside its native range as an ornamental garden plant.

However, Mr Baldacchino said its overall negative impacts were devastating. He believes it was originally imported as a garden plant and then it “either escaped accidentally or somebody dispersed its seeds intentionally”.

The seeds are dispersed by water and air and the plant forms dense infestations out­competing indigenous vegetation. Its weight can also cause branches to break.

4. Cardiospermum grandiflorum deadly seeds

3. Cardiospermum grandiflorum deadly seeds

Such is the negative impact on indigenous species that it has been listed as a noxious weed in South Africa, Australia, the US and New Zealand, according to Mr Baldacchino.

Its invasiveness is so acute it has been added to the European and Mediterranean Plant Protection Organisation Alert list, he said.

Invasive alien species were spreading all over the world mainly because of transport and the ornamental garden industry, he pointed out, adding that some people claim the damage by these species was more acute than climate change.

5. Cardiospermum grandiflorum thicket at Wied Babu

4. Cardiospermum grandiflorum thicket at Wied Babu

A number of international conventions, such as the Convention on Biological Diversity and also the EU Environmental Acquis, tackle invasive species. The EU has an ad hoc committee that is studying the spread and drafting additional regulations for immediate control.

Malta is obliged to honour these provisions, which have been transposed into local legislation.

A number of publications such as the National Environment Policy and the Malta Environment and Planning Authority ‘s new guidelines for the management of invasive plants were published but no enforcement or monitoring was being done.

Mr Baldacchino said one of the measures was to stop the plant from expanding.

8. Cardiospermum grandiflorum deadly seeds

5. Cardiospermum grandiflorum deadly seeds

“This is not relatively difficult, though it needs manpower, and ongoing monitoring to uproot seedlings and established plants is urgently necessary,” he added.

Mr Baldacchino said he had received reports from the Flimkien Għal Ambjent Aħjar Tree Group that the vine was also spreading up the trees along Birkirkara’s Valley Road.

He informed the Environment Ministry and the planning authority, which said they were studying the matter.

The best form of management and control was prevention, which “unfortunately is completely absent”.

Where these plants have set root, Mr Baldacchino said, the best control method was to weed them before they seeded to reduce the dispersal.

Consistent follow-up was required for sustainable management.

“This is quite a heavy economical, social and ecological price that we have to bear following neglect and inadequate attention to prevent such alien species from establishing themselves,” he said.

 

Further reading:

https://alfredbaldacchino.wordpress.com/2012/10/29/eu-stand-on-invasive-species/

https://alfredbaldacchino.wordpress.com/2010/06/21/the-introduction-of-alien-species-into-the-natural-environment-%E2%80%93-a-european-concern/

https://alfredbaldacchino.wordpress.com/2010/07/25/the-red-palm-weevil-another-alien-species/