Rafael GuargaFruit trees come in from the cold

Published in 1998icon-clockTime to read: 0min 43s

In a few hours, overnight frost can destroy a crop of fruit. But a machine invented in Uruguay is providing a solution in orchards on several continents.


Orchardists around the world spend millions of dollars on expensive and labour-intensive ways to protect crops from frosts.

The interaction between theory and careful experimentation has always strongly attracted me. I also like to work on the problem in front of me.

But engineer Rafael Guarga, having witnessed the devastation caused by frost to citrus fruit crops in his own country, developed the Selective Inverted Sink system (SIS) and later patented the device.

A motorized fan sucks up the frost-forming air and expels it 100 metres above the fruit trees, dispersing it into warmer layers of air. The SIS is used on crops grown across thousands of hectares on hundreds of farms from New Zealand to Spain. Guarga, the President of Frost Protection Corporation, believes it is likely that, with increasing frost damage due to climate change, the SIS system will be installed to protect many more thousands of hectares in the next few years.

  • 14

    Countries in which SIS is used to protect crops

  • 8

    Countries in which patents have been issued for SIS technology


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