Late frosts represent one of the most relevant natural hazards worldwide for farming production, considering severity and extent of damage, whose occurrence is constantly increasing, concomitantly to the increase of climate change and variability.
Therefore, impacts on the farming economy are devastating, so information about how to protect plants from frost is becoming relevant. The knowledge of local meteorology should support the acquisition of passive protection systems and to improve the active ones.
But one thing is absolutely essential for all systems: you must start in time. One of the main causes of frost damage is that protection systems are being started too late, for many reasons:
- growers do not have a frost alarm system
- growers are starting their protection system based on a dry temperature
- the frost alarm is not placed in the right place
- the temperature sensor is installed too high
What should a frost protection system consist of?
Several methods have been identified to protect plants against frost and the availability of accurate information is crucial.
Farmers urgently need the following information before activating a frost protection system: site-specific weather forecast, accurate real-time information about temperature and other key frost parameters in their crops.
In particular, wet bulb temperature better represents the temperature of the leaf during frost conditions and it tells the right moment when to start the irrigation system.
What should you pay attention to?
The threshold temperature for damage varies with crop and season. In general, an official temperature of 0°C, will have a negative effect on crops of any crop height, but between 0+2°C the frost effect is variable.
Be aware that sprinklers can cause more harm than good: apply enough water at the right time. Sprinklers should be started before wet temperature drops below 0°C — set the minimum threshold of wet temperature in FieldClimate at +1°C — depending on the crop’s different phenological phases and critical damage temperature.
Site selection is also very important: sensor should be installed in the coldest spot of the orchard/vineyard (lower sites have lower temperature) and at the height of the lowest flowers or fruits.
Monitoring dew point is also a solution, but only under the most common frost scenarios. The parameter is available on the platform Fieldclimate. The rule of thumb is that the Tmin on a given morning will approach the dew point value taken the prior evening.
What solutions does METOS® by Pessl Instruments offer?
Frost can be measured and anticipated with µMETOS NB-IoT FROST (communication via NB-IoT), µMETOS CLIMA LoRa FROST (communication via LoRaWAN®) or iMETOS FROST (operating with a sim card 2G/3G/4G) weather stations, and get alerts in near real-time by SMS, email or app notifications. When the set temperature is reached, it sends an alarm warning message. All the data are available also through our mobile app Android & iOS Fieldclimate and the web-platform fieldclimate.com.
With METOS® weather station you get the best forecast for your farm and fields by using real-time local measurements to post-correct modeled forecast output, eliminating model bias and updating the forecast frequently with the last data from your station, satellite and radar. Artificial intelligence is further used to increase the models skill and optimally combine/select the best forecast models at any particular location.