The Threat Of Olive Ebola

On Thursday, the co-operative Camp Mallorquí will be holding a conference in Palma. It will address issues such as technological innovation in agriculture, commercial opportunities and the future of farming co-operatives. But these will not be agricultural issues in general. There is one theme to the conference: almonds.

A further issue that will be discussed will be diseases and pests, and it is this issue which is by far the most pressing on the agenda. Almond trees are under renewed danger. So are olive trees. The danger comes in the form of a bacterium called "xylella fastidiosa".

Of American origin, this has already started to have a devastating effect on olive and almond trees in Italy and has now spread to France. Some 100,000 hectares of tree crops in Italy have been affected. There is no remedy other than to cut trees down and burn them in the hope of stopping the bacterium spreading. Which is a big hope. The bacterium is transmitted by leafhopping insects, which are extremely common.

So damaging has the bacterium been that it has acquired a deadly name - "olive ebola". It has not been detected in Mallorca, but farmers are naturally fearful that it might be. The consequences of it arriving on the island and taking hold could be enormous in terms of the island's economy and landscape. Its potential harm would greatly exceed that of the attacks on pines by processionary caterpillars or on palm trees by the "picudo rojo", the red beetle.

It poses a threat that is reminiscent of the phylloxera "plague" of the late nineteenth century. Mallorca had benefited greatly from the devastation of French vines by phylloxera earlier in that century. But when it arrived on Mallorca in the 1890s, the consequences for some rural areas of the island were catastrophic. Though it has since been argued that phylloxera was not as damaging as had been thought, there is no arguing the fact that it contributed to emigration and to a major shift in agricultural production. The vines were to return, but it is fair to say that the Mallorcan wine economy, a staple for so many centuries, didn't truly start its recovery until the 1970s, though the Franco regime had to take some of the blame for this delay because of its one-time insistence on an equally catastrophic self-sufficiency economic policy which placed an emphasis on subsistence crops.

There is a certain similarity between phylloxera and xylella fastidiosa. The grape phylloxera insect sucks sap from and feeds off leaves and roots. The result can be a fungal infection. Xylella fastidiosa insects also suck sap and transmit the bacterium in the process. There is still no actual remedy for phylloxera, though it has been combated by introducing resistant rootstock which creates a type of sap that repels the insect. As yet, a similar means of combating xylella fastidiosa appears not to exist.

At present, there is no formalised system of control against xylella fastidiosa, but the farming community wants controls of imported trees and of nurseries to be stepped up. A positive bit of news is that olive trees are typically imported from Andalusia where there is no evidence of the bacterium but also where the alert was first raised: the government in Andalusia, which has tightened its controls, was the one to let the rest of Spain know about the potential harm.

So, the threat, for the moment, is a hypothetical one, but as was seen with the palm beetle, it was public administration inertia that helped its diffusion. Before it truly took hold in Pollensa (where it is commonly said to have first been detected), attention was being drawn to an infection of palm trees. If local authorities had acted more swiftly, the loss of the island's palms would not now be as great as it is. At least, though, the threat is known about this time and it is one that would have greater economic consequence than the beetle. There are almost 25,000 hectares dedicated to almond production and a further 8,000 or so to olives, approximately a quarter of these for oil that has a protected designation of origin - the highly prized Mallorcan olive oil.

But there would be another consequence. Though the volume of farming land devoted to almonds has decreased significantly from what it once was, it has now stabilised, and it is almond production which gives Mallorca one of its most characteristic landscape features - the blossom of late winter. If this were to be threatened, if this were to disappear, there would be a loss very much greater than a mere economic one. And, unfortunately, there is more. It isn't just olive and almond trees that can be affected. So too can oleander and citrus trees, meaning lemon and orange groves. Just hope to God the bacterium stays away.