Early detection of 'olive tree leprosy' with drones

This file photo taken on February 11, 2016 shows olive trees infected by the bacteria "Xylella fastidiosa" in Gallipoli near Lecce, in the Puglia region. (AFP)
Updated 26 June 2018
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Early detection of 'olive tree leprosy' with drones

  • The bug has also attacked orchards in Spain and France, and both Greece and Portugal are bracing for its likely arrival
  • The only way to fight the spread of what is known as "olive tree leprosy" is to destroy diseased trees

PARIS: A bacterial infection ravaging olive orchards in southern Europe can be detected from small planes or drones well before symptoms appear, offering panicky growers the prospect of an early warning system, scientists said Monday.
Using high-tech cameras that detect heat and the electromagnetic spectrum from X-ray to radio waves, researchers were able to spot diseased trees that, on the ground, still seemed healthy, they reported in the journal Nature Plants.
"After infection, it takes four to 14 months before visual symptoms are observable by plant pathologists in the field," lead author Pablo Zarco-Tejada, an agricultural engineer at the European Commission's Joint Research Centre in Ispra, Italy, told AFP.
"The problem is that during this entire time the tree remains a potential source of infection."
Once Xylella fastidiosa bacteria -- carried by tiny sap-sucking insects known as leafhoppers -- take hold, there is no cure and the plant is doomed.
The only way to fight the spread of what is known as "olive tree leprosy" is to destroy diseased trees.
"Early detection is critical for the eradication of the bacteria," Zarco-Tejada said.
Since it hit the Apulia region in 2013, the microscopic pathogen has killed more than a million olive trees in Italy, and 10 million more are currently affected.
The bug has also attacked orchards in Spain and France, and both Greece and Portugal are bracing for its likely arrival.
Some 350 plants are vulnerable, including grape vines, citrus and almond trees.
Known in the United States as Pierce's disease, it devastated California vineyards in the late 19th century.
To test their approach, Zarco-Tejada and international team of researchers fitted thermal and hyperspectral cameras on a small plane, and then analysed images of orchards.
At the same time, they tested olive trees on the ground for infection.
They found that the bacterial infection can be remotely detected three to six months before visible symptoms appear.
"We extracted the spectral signature and the temperature from each single tree crown," Zarco-Tejada said.
The data were then fed into a model built with machine-learning methods.
The cameras can be easily installed on planes or drones, similar to ones used for aerial photography and surveillance. The cost would depend in part on the size of the area covered.
The insect-borne pathogen has likely spread more quickly as global warming takes hold, according to a study published earlier this year in the journal Biorxiv.
But a more immediate factor in its expansion is probably global trade, the study said.
The authors are currently measuring for Xylella fastidiosa in almond orchards in central Spain.
Italy and Spain together account for nearly 70 percent of global olive oil output, according to the International Olive Council (IOC).


Japan satellite blasts into space to deliver artificial meteors

Updated 18 January 2019
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Japan satellite blasts into space to deliver artificial meteors

  • The rocket is carrying a total of seven ultra-small satellites that will demonstrate various “innovative” technologies
  • The satellite carries 400 tiny balls whose chemical formula is a closely-guarded secret

TOKYO: A rocket carrying a satellite on a mission to deliver the world’s first artificial meteor shower blasted into space on Friday, Japanese scientists said.
A start-up based in Tokyo developed the micro-satellite for the celestial show over Hiroshima early next year as the initial experiment for what it calls a “shooting stars on demand” service.
The satellite is to release tiny balls that glow brightly as they hurtle through the atmosphere, simulating a meteor shower.
It hitched a ride on the small-size Epsilon-4 rocket that was launched from the Uchinoura space center by the Japan Aerospace Exploration Agency (JAXA) on Friday morning.
The rocket is carrying a total of seven ultra-small satellites that will demonstrate various “innovative” technologies, JAXA spokesman Nobuyoshi Fujimoto told AFP.
By around noon on Friday, the first of the seven satellites had been successfully sent into orbit, he added, with JAXA officials waiting for signals to confirm the fate of the other six.
The company behind the artificial meteor shower plan, ALE Co. Ltd, plans to deliver its first out-of-this-world show over Hiroshima in the spring of 2020.
The satellite launched Friday carries 400 tiny balls whose chemical formula is a closely-guarded secret.
That should be enough for 20-30 events, as one shower will involve up to 20 stars, according to the company.
ALE’s satellite, released 500 kilometers (310 miles) above the Earth, will gradually descend to 400 kilometers over the coming year as it orbits the Earth.
The company plans to launch a second satellite on a private-sector rocket in mid-2019.
ALE says it is targeting “the whole world” with its products and plans to build a stockpile of shooting stars in space that can be delivered across the world.
When its two satellites are in orbit, they can be used separately or in tandem, and will be programmed to eject the balls at the right location, speed and direction to put on a show for viewers on the ground.
Tinkering with the ingredients in the balls should mean that it is possible to change the colors they glow, offering the possibility of a multi-colored flotilla of shooting stars.
Each star is expected to shine for several seconds before being completely burned up — well before they fall low enough to pose any danger to anything on Earth.
They would glow brightly enough to be seen even over the light-polluted metropolis of Tokyo, ALE says.
If all goes well, and the skies are clear, the 2020 event could be visible to millions of people, it says.
ALE chief executive Lena Okajima has said her company chose Hiroshima for its first display because of its good weather, landscape and cultural assets.
The western Japan city rose from the ashes after the 1945 US atomic bombing and faces the Seto Inland sea where the floating gate of Itsukushima Shrine is.
ALE is working in collaboration with scientists and engineers at Japanese universities as well as local government officials and corporate sponsors.
It has not disclosed the price for an artificial meteor shower.