23rd Conference on Applied Climatology, Asheville, North Carolina, USA

1. CROP DAMAGE DUE TO FROST ACROSS TWO
DIVERSE AGRO-ENVIRONMENTS
Tanja Likso
Meteorological and Hydrological Service of
Croatia
Surender Singh
Dept of Agricultural Meteorology
CCS Haryana Agril University, Hisar,
India

2. Introduction
• Extreme climate conditions such as heat and cold
waves and extremely dry and wet periods are of
particular importance because they affect both
people and economy
• Recognising these periods on different time scales
(month, season, year) is an excellent basis for further
analysis of their impact on the economy (agriculture,
tourism, transport, etc.) and sometimes,
unfortunately, it results in the loss of human lives

3. Fig. 1 Geographical location of Croatia in the European Union.

4. Zagreb – capital of Croatia
Dubrovnik

5. Climate of Croatia
Climate of Croatia is determined by its position in the northern mid-
latitudes and the corresponding weather processes on a large and
medium scale
• 3 climate zones
• Continental Croatia – temperate continental climate
• At higher altitudes (> 1200 m asl) – in the mountainous
districts of Gorski kotar and Lika and the Dinaric Alps -
mountain climate
•Along the Adriatic coast prevails pleasant mediterranean
Climate
• Köppen climate classification – most of Croatia has a temperate
rainy climate with an average monthly temperature higher than
-3°C and lower than 18°C in the coldest month
• Only the highest mountain areas (> 1200 m asl) have a snow-
forest climate with an average temperature lower than -3°C in
the coldest month

6. Climate of Croatia
• Inland  the warmest month of the year has an average
temperature lower than 22°C, in the coastal area higher than 22°C,
and more than four months within one year have a monthly average
temperature higher than 10°C.
• On the islands and in the coastal area of the Middle and Southern
Adriatic, there is a prevalent olive climate, which means that the dry
period is in the warm part of the year, and the driest month has even
less than 40 mm of precipitation, less than a third of the amount in
the rainiest month in the cold part of the year. There are two
precipitation maxima in the larger part of the area.

7. Climate Monitoring
Fig. 2 Average daily air temperatures at Zagreb-Grič in 2016 relative to the long-
term average (1862-2015) and daily precipitation amounts in 2016.

8. Climate Monitoring
Fig. 3 Average annual air temperature anomalies in the year 2016 relative to
the multiannual average for the period 1961 – 1990.

9. Fig. 5 Annual course of mean (tmin5cm) and the lowest minimum air temperature
at 5 cm (tmin5cmmin) (left scale, °C) and the number of days with minimum air
temperature at 5cm below 0°C (tmin5cm < 0°C) (right scale, days).
Fig. 4 Mean annual number of frost days (tmin < 0°C),
for Croatia. Author: Melita Perčec Tadić

10. Fig. 6 Tmax and Tmin anomalies
relative to the multiannual
average for the period 1981 –
2010 and forecast for the last
decade of April 2016 for the main
meteorological station Split-
Marjan. Author: Zoran Vakula,
Chief Meteorologist, Croatian
Radio and Television
Fig. 7 The same as in Fig. 6 but for
Zagreb-Maksimir Observatory.
Author: Zoran Vakula, Chief
Meteorologist, Croatian Radio and
Television

11. Fig. 8 Isohypse and isotherm distribution in
850 hPa isobaric surface in wider European
territory on 26 April 2016 at 06 UTC.
Fig. 9 Isohypse and isotherm distribution in
AT 500 hPa isobaric surface in wider
European territory on 26 April at 06 UTC.
The cold spell at the end of April 2016 in Croatia

12. Fig. 10 Minimum daily air temperature at 2m
above the ground in wider Croatian territory
and territory of neighbouring countries on 26
April 2016.
Fig. 11 Minimum air temperature at 5 cm
above the ground in wider Croatian
territory and territory of neighbouring
countries on 26 April 2016.
The cold spell at the end of April 2016 in Croatia

13. Frost day – a day on which the minimum air
temperature in the thermometer shelter falls
below 0°C (32°F)
Frost days occur inland (Croatia) from October
to April and on the Adriatic coast from
December to March and they are not very
frequent
Mean number of frost days in arid zone of
Haryana  January (12.7), December (8.5) and
February (5.7) (Satyawan et al., 2008)

14. Fig. 12 Frozen cherry blossom
(source: www.agroklub.com)
Fig. 13 Vineyard hit by frost
(source: www.agrobiz.hr/agrovijesti)
On 26 April 2016  frost damage in
fruit farming across Croatia was
estimated to more than 105 million
Euros
Several countries declared a state of
natural disaster.
Frost affected north-western, central
and part of eastern Croatia, as well as
the hinterland of the east coast of the
central Adriatic.

15. Agrometeorological Observatory, Hisar, Haryana, India
Latitude: 29010’N; Longitude: 75046’E; Altitude: 215.2 m amsl
Tropical climate with very hot summers and very cold winters.
Extreme Temperatures : Highest 47.50C Lowest -3.50C
Avg Frost Events : 06
Avg Foggy Events: 30
Rains (Winter/Monsoon/Annual) : 030 / 352 / 462 mm
Rainy Days (Winter/Monsoon/Annual) : 004 / 020 / 030
N Delhi

16. Frost Observations in Research Field
Frost on Grass Minimum
Thermometer
Free zed water in US OpenPan
Evaporimeter
Dew freezed on Duvdevani's Dew
Gauge Plates
Ground frost in Observatory Foggy day in Brassica field

17. Visible Symptoms of frost
Wheat Brassica
Brassica Guava

18. Visible Symptoms of frost
Tomato Chilly
PapayaBrinjal

19. Visible Symptoms of frost
Marigold Rose
Brinjal

20. Frost damage in crops
Vegetable Crops : Potato, Tomatoes, Chillies,
Capsicum, Brinjal, Peas
(upto 70 % Loss)
Fruits tress : Guava, Ber, Papaya
(20-50 % Loss)
Field crops : Wheat, Brassica Spp
Chickpea, Barley
(upto 10 % Loss)
Because of chilling , freezing & physiological
injuries, reduced photosynthesis and rust diseases

21. Conclusion:
• Improve emphasize the accurate forecast
value of frost warnings.
• Medium range weather forecasts and
weather-based farm-advisories
• Contingent measures for implementation
after issuing of early warnings on cold
wave, frost events with reference to crops

22. Conclusion
• An accurate weather forecast is of high importance as well
as warnings for extreme weather
• In order to avoid/mitigate frost damages  measures as
fire burning in orchards, air mixing by fan, spraying above
the crown
• To help plants recover from stress caused by low tempera-
tures  treatment of damaged crops by some of the
biostimulators