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Servir’s Fight Against Frost
Kenya’s economic back bone is primarily agriculture, sustained
by both subsistence and large scale farming. Tea and coffee
are major sources of income and foreign exchange. The
slightest fluctuation in production of these crops greatly affects
the economy. Temperatures in some areas of Kenya can drop
steeply, causing frost to form, which can damage crops. As the
temperature drops, the water inside a tea plant's cells changes
from liquid to solid, expanding and forming ice crystals and
rupturing the cell walls. Oxidation then turns the leaves brown.
Tender young shoots, which have high moisture content, are
the most prone to damage. Therefore a search for a remedy to
the seasonal peril of frost recently took the forefront.
Automated frost
mapping supported by
wireless sensor
networks.
GOOGLE
Frost damaged tea leaves.
"Tea farmers in any part of
the country depend on TRFK
for research and
improvement. That is why we
thought it was good to start
here and use this network to
reach more farmers and
companies."
Absae Sedah, Kericho
County Director of
Meteorology, Kenya
Meteorological Service.
For more information, please contact:
Anastacia Wahome at
awahome@rcmrd.org
When the Tea Research Foundation of Kenya (TRFK)
requested a way to receive advance notice of possible frost,
RCMRD/SERVIR-Eastern and Southern Africa developed and
installed an automated frost mapping system. The system
emails user friendly maps identifying areas with high potential
for frost to the Kenya Meteorological Service (KMS), TRFK, and
agricultural insurance companies. KMS alerts then give farmers
time to protect their crops when frost threatens.
How the system works: The frost alert system identifies and
displays potential frost impacted areas by analyzing night time
land surface temperature data from NASA's Moderate
Resolution Imaging Spectroradiometer (MODIS) aboard the
Terra and Aqua satellites. A Wireless Sensor Network (WSN)
also installed by RCMRD/SERVIR and covering a tea growing
area in Kericho-supports the system by providing field
observations of temperature, wind speed, and humidity in
sample locations within the tea fields at TRFK.
The frost alert system will also soon incorporate KMS Weather
Research and Forecasting model (WRF) numerical prediction
model forecasts to increase the accuracy of the weather
forecasts the frost alerts are based on. The WSN observations
are correlated with the forecasts and satellite data products. All
of this serves to more accurately define frost condition
thresholds and to identify conditions when tea farmers should
use frost damage mitigation strategies.