It’s all systems go as growers prepare for a glacial weekend here in the Loire. Temperatures are set to drop below zero in the early hours of tomorrow and Sunday morning. Bales of straw have been strategically placed at the end of rows (they will be set alight), portable blowers have been put in place and bougies (candles) are waiting to be lit.
All we can do is wait and hope for the best. Frost preventative measures can be efficient but it does depend upon the type of frost, wind speed and humidity.
The picture shows a mobile blower a ‘tow and blow’ that can be moved around to protect different parcels of vines. They are efficient up to -3°C and can protect up to 3 hectares of vines (around 7.5 acres). They are only efficient in the case of a radiatif frost. This is when the soil loses the heat accumulated during the day after the sun has gone down. The hot air rises to the sky and the colder denser air accumulates at ground level on the soil. The amount of humidity in the air determines whether the frost is white or black in nature. Higher humidity results in a white frost and dry clear nights result in a black frost.
