By IANS/EFE,
Buenos Aires: The use of cannons to tackle hailstones has set off a fierce fight between fruit growers, who use them to protect their crops, and cattle raisers, who believe they cause drought.
The “battle” has been going on for several years but has now escalated to the point that in the coming days it will have to be resolved by the Argentine Supreme Court.
Farmers and cattle raisers in Buenos Aires, La Pampa and Rio Negro provinces are seeking a supreme court ruling banning the use of hail cannons in Colorado river valley that produces apples, pears, cherries and peaches.
The cannons, installed in that area in 2005, use gas to produce repeated explosions when clouds come near. The rapidly expanding shock waves are believed to break the hail, which then falls on earth in the form of slush or rain.
“What really happens is that the clouds break up and dissipate, and do not rain. All around the places where they use these devices is a ring of drought,” Edgar Kronemberger, a cattle rancher in Buenos Aires province, who is leading the crusade against use of hail cannons, told EFE.
The farmers and livestock raisers in the affected regions believe the drying up of rainfall in the area since 2005 is related to the use of hail cannons.
“In the last five years we have lost everything,” Kronemberg said, adding that just in Caleu Caleu, one of the affected provinces of the pampas, 200,000 cattle have died because of drought.
According to attorney Manuel Saez, who will bring the case before the supreme court, provincial laws on the use of water also regulate the use of rainwater, so fruit growers must seek permission to use hail cannons.
“Fruit growers use irrigation water, so they don’t need rainwater and fight the clouds as if they were a curse, but they don’t stop to think that the use of cannons is changing the climate,” Saez told EFE.
However, the attorney acknowledged it is “difficult” to determine the cause-effect relationship between the action of cannons and drought.
What is certain is that the effectiveness of these devices to ward off hail is questioned by a series of international studies.
“We do not recommend the use of these cannons because their effectiveness in combating hail has not been demonstrated,” Miguel Angel Tassara, an expert at the National Institute of Agricultural Technology, told EFE.
Tassara said there is no evidence the use of these devices has any connection with drought.
“Experts say the cannons are useless. But the truth is, ever since we have been using them, no hailstones have fallen. Maybe it’s just a belief, but we use them just in case,” the president of the Agricultural Producers Chamber of Rio Colorado, Ruben Perez, told EFE.
In his opinion, although the cannons are fired, it rains anyway, so they can’t be blamed for the drought. Perez said he never authorised to use of cannons. He said cannons are used in Rio Negro valley for 30 years.
Hail is also combated in other regions of Argentina, but with another method.
For example, in the western province of Mendoza, the biggest winegrowing region in the country, silver iodide is used to prevent the formation of large hailstones capable of destroying the vineyards. The chemical substance is released in the air through airplanes and rockets.