Strawberry leaf surface temperature dynamics measured by thermal camera in night frost conditions
Vaata/ Ava
Aasta
2018Autor
Kokin, Eugen
Pennar, Madis
Palge, Veli
Jürjenson, Kuno
Metadata
Näita täielikku nimetuse kirjetKokkuvõte
The aim of the study was to define the strawberry leaf surface and ambient air
temperature differences in night frost conditions. The study was carried out at the commercial
strawberry field in late autumn at a specific natural climatic situation, corresponding to night frost
conditions. Thermal camera FLIR P660 was used for obtaining thermal images and corresponding
visual colour images of the strawberry leaves. The images were taken at ten-minute interval. The
ambient air temperature, relative humidity, dew point, solar radiation and wind speed data were
obtained by Davis Vantage Pro2 weather station. It was estimated that the surface temperature of
the specific leaf is comparatively similar at different parts of the specimen and changes noticeably
with the variation of solar radiation intensity. The speed of temperature changes was also
analysed. During all the measurement period, the considerable difference between the
temperature of the leaf and the ambient air temperature was established, especially in absence of
solar radiation. The difference of the leaf surface and ambient air temperature reached 8 °C. The
study showed that in night frost conditions the plants might be endangered by low temperatures
even at the air temperatures above 0 °C due to intensive energy loss by long wave radiation to the
sky. It is suggested that the thermal imaging or infrared radiation measurement should be used
simultaneously with air temperature measurements for more exact timing of night frost
prevention measures at strawberry cultivation.