selected agro-climatic characteristics and
wine-grape yields in the southern moravia
Ondrej Antoš
Gymnazium a Stredni odborna škola pedagogicka Znojmo, Pontassievska 3, 669 02 Znojmo, Czech Republic e-mail: antos@gymspgs.cz
Pregledni znanstveni članek COBISS 1.02
Abstract
The sums of average daily temperatures higher than 10 °C (TS10) in the period from April to September describe the temperature conditions in the given area. The absolute precipitation sums concerning the season, i.e. from April to September, and the Seljaninov's Hydrothermical Coefficient (HTC) during the period from June to August describe precipitation and moisture conditions. The HTC values confirm the fact that the South Moravian region belongs among the most arid regions in the Czech Republic. The attention is, also, devoted to connections between the wine-grape yield and the weather conditions in 1997, an abnormal year from the meteorological point of view.
Key words: winegrowing, temperature sum, precipitation sum, Seljaninov's Hydrothermical Coefficient, wine-grape yields, Southern Moravia, decade 1993 - 2002.
NEKATERE AGROKLIMATSKE ZNAČILNOSTI JUŽNE MORAVSKE
pomembne za vinogradništvo
Izvleček
Razmere, primerne za uspevanje vinske trte, najbolje ponazarja vsota povprečnih dnevnih temperatur višjih od 10 0C (TS10) v obdobju od aprila do septembra. Padavinske razmere obravnavanega območja v rastni sezoni so predstavljene s pomočjo podatkov o količini padavin, vlažnostne razmere od junija do avgusta pa s pomočjo Seljaninovega hidrotermičnega koeficienta (HTC). Vrednosti HTC pritrjujejo znanemu dejstvu, da spada Južna Moravska med najbolj sušna območja na Češkem. Posebna pozornost je v prispevku namenjena tudi vinski letini in vremenskim pogojem v letu 1997, ki je bilo z meteorološkega vidika neobičajno.
Ključne besede: vinogradništvo, temperaturne vsote, količina padavin, Seljaninov hidro-termični koeficient, vinska letina, Južna Moravska, Republika Češka.
1.	INTRODUCTION
This article presents the results of the dissertation called "The agro-climatic conditions of winegrowing in the area of Southern Moravia" (elaborated in cooperation with the Department of Geography, Natural Science Faculty, Palacky University in Olomouc, Czech Republic). The main part of this dissertation is the analysis of the agro-climatic conditions in chosen locations during the 1993 - 2002 decade.
2.	METHODS AND DATA
The author deals with meteorological characteristics in the period of time from 1993 to 2002. For such an analysis two main criteria were taken into consideration: air temperature and precipitation sums. These characteristics were elaborated for selected meteorological stations in the Southern Moravia: Znojmo - Kucharovice, Dyjakovice, Brno - Turany, Velke Pavlovice and Stražnice. These stations are perceived as representatives of "Morava" winegrowing region in the Southern Moravia (Fig. 2.1.). It is necessary to say that the station situated in Mikulov winegrowing sub-region is not included in this paper. Due to the short span of time (mainly concerning the data set), trend and variability were not researched. In some years the connections between wine-grape yield (an agricultural product typical of the Southern Moravia) and the course of meteorological elements have been discussed.
Figure 1: Winegrowing region Morava according to Regulation No 324/2004 Coll.
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Statistical data concerning yield values were provided by Central Institute for Supervising and Testing in Agriculture (UKZUZ), the Division of Perennial Plants. Meteorological data were provided by Czech Hydrometeorological Institute (CHMU) in Brno.
Table 1: Selected meteorological stations in the area of Southern Moravia (CHMU, 2003)
Name of station	Elevation (m)	Geographical location
Znojmo - Kucharovice	334	48° 52' 57'' N, 16° 05' 11'' E
Dyjakovice	201	48° 46' 24'' N, 16° 17' 51'' E
Brno - Turany	241	49° 09' 35'' N, 16° 41' 44'' E
Velke Pavlovice	196	48° 53' 57'' N, 16° 49' 28'' E
Stražnice na Morave	176	48° 46' 24'' N, 17° 20' 17'' E
All computations, tables and graphs were created using Microsoft Excel tools, maps were created in ArcGIS 9.0.
3. TEMPERATURE CONDITIONS
Air temperature is the determinative factor for winegrowing. In the Table 3.1., the value sums of average daily temperatures higher than 10 °C (further as TS10) in the period from April to September 1993-2002 are shown. TS10 reaches 2200 °C (for the earliest cultivars) and about 3000 °C (for very late cultivars) in the Czech Republic. However, TS10 in southern winegrowing regions is frequently higher, e.g. in South African Republic 6000 °C. The growing season in northern winegrowing regions (also in the Czech Republic) is reduced using early and semi-early cultivars, so under the same conditions we get better quality wine.
Table 2: Temperature sums TS10 during IV-IX (oC) in selected stations in Southern Moravia in 1993-2002
Station / Year	1993	1994	1995	1996	1997	1998
Velke Pavlovice	2845.1	3068.3	2843	2714.7	2785.5	3022.4
Brno - Turany	2806.3	2995.3	2776.9	2541.7	2667.8	2885.6
Stražnice	2795.7	2922.2	2719.8	2554.7	2571.9	2910.2
Kucharovice	2694.5	2870.1	2641.3	2351	2539.9	2720.8
Dyjakovice	2881.8	3021.8	2869.1	2652.7	2756.1	2976.5
Average	2804.68	2975.54	2770.02	2562.96	2664.24	2903.1
Station / Year	1999	2000	2001	2002	1993-2002
Velke Pavlovice	3104.4	3149.2	2784.3	2993.7	2931.06
Brno - Turany	3014.5	3078.7	2712.7	2936.3	2841.58
Stražnice	2898.2	2936.4	2657.1	2847.2	2781.34
Kucharovice	2793.4	2900.7	2592.9	2847.7	2695.23
Dyjakovice	3019.4	3112.2	2830.9	2999.1	2911.96
Average	2965.98	3035.44	2715.58	2924.8	2832.234
The Znojmo winegrowing sub-region has a really good net of meteorological stations. Each of the stations (Kucharovice, Dyjakovice) measured quite different values. The
Dyjakovice station measured the highest values (which were as high as over 3000 °C - in 1994, 1999, 2000). On the other hand, Kucharovice was the coldest meteorological station in the decade. In the coldest year of the decade (1996), TS10 reached only 2351 °C.
From the Table 3.1., we can see that in Velke Pavlovice locality highest values were reached in 1993-2002. The values over 3000 °C occurred four times. Even in the coldest year of the decade (1996) TS10 was still over 2700 °C.
4. PRECIPITATION SUMS AND MOISTURE CONDITIONS
In this chapter an attention has been devoted to two parameters: Absolute sums of precipitation in the period from April to September and the Seljaninov s Hydrothermical Coefficient.
4.1 Precipitation
Precipitation sum belongs among other agro-climatic characteristics that affect winegrowing. For winegrowing, especially seasonable precipitation during the whole growing season is important.
Table 3: Absolute precipitation sums (mm) in selected stations in the period IV- IX in the decade 1993 - 2002
Station / Year	1993	1994	1995	1996	1997	1998	1999	2000	2001	2002	93-02
Velke Pavlovice	285.9	265.4	466.8	361.3	414.5	374.0	334.2	283.5	389.3	360.6	353.6
Brno - Turany	290.0	310.1	365.2	354.6	416.5	383.1	306.8	245.6	408.5	344.5	342.5
Straznice	244.1	343.1	344.0	378.9	372.4	350.9	327.9	283.4	353.6	301.9	330.0
Kucharovice	295.4	252.4	429.6	411.4	384.5	320.8	356.4	297.2	314.5	471.9	353.4
Dyjakovice	312.3	235.4	434.7	363.8	431.0	302.1	364.0	250.2	333.5	392.7	342.0
average	285.5	281.3	408.1	374.0	403.8	346.2	337.9	272.0	359.9	374.3	344.3
Figure 3: Absolute precipitation sums (mm), April - September 1997 in selected stations in the Southern Moravia
1/4 8/4 15/4 22/4 29/4 6/5 13/5 20/5 27/5 3/6 10/6 17/6 24/6 1/7 8/7 15/7 22/7 29/7 5/8 12/8 19/8 26/8 2/9 9/9 16/9 23/9 30/9
-Bmo416.5mm-D)jäkovic9 431 mm Kucharovice 384,5 mm Stražnice 372 mm-V. Pavlovice 414,5 mm
In the decade 1993-2002 we may notice the abnormal character of the year 1997. The Figure 4.1.1. shows the distribution of precipitation sums during the season from April to September in the 1997. It is evident that the precipitation sums were evenly placed until June and did not reach extremes. However, after that (from the first decade of July on) it rained a lot during a very short period of time. The rainy period lasted for approximately 14 days. There was almost no precipitation in August. Its possible consequences for wine-grape yield are discussed in the chapter 5.
4.2 Moisture conditions
Under the term - moisture conditions we understand the amount of available water in the soil (Dobrovolny 1996, p. 188). The relation between precipitation and potential evaporation denote the Seljaninov's Hydrothermical Coefficient (further HTC) which can be expressed by the following relation:
HTC-
. R
'0,1! t
where R ... absolute precipitation sum during summer months (VI - VIII)
Xf ... the sum of average daily temperatures 10 °C or higher during summer months (VI - VIII)
The significant value for HTC is 1. The areas with HTC < 1 (in the long-term perspective) are called as "arid" and the areas with HTC > 1 as "humid". The next table shows the values of HTC at selected stations in the Southern Moravia in the 1993 - 2002.
Table 4: Seljaninov's Hydrothermical Coefficient, from June to August, 1993 stations in the Southern Moravia
2002, selected
Station/year	1993	1994	1995	1996	1997	1998	1999	2000	2001	2002	AVERAGE
Brno-Turany	1.27	0.73	0.95	1.19	1.83	1.12	1.11	0.99	1.14	1.24	1.16
Dyjakovice	1.12	0.60	1.18	1.29	1.94	0.83	1.40	0.87	0.62	1.51	1.14
Kucharovice	1.05	0.39	1.30	1.38	1.68	0.93	1.40	1.22	0.94	1.72	1.20
Straznice	1.10	0.84	1.08	1.08	1.74	1.03	1.34	1.07	0.98	1.22	1.15
Velké Pavlovice	1.19	0.72	1.47	1.01	1.80	1.06	1.25	1.14	1.23	1.44	1.23
AVERAGE	1.15	0.66	1.20	1.19	1.80	0.99	1.30	1.06	0.98	1.43	1.17
The average values (in the decade 1993-2002) of HTC confirm the fact that Southern Moravia region belongs among the most arid regions in the Czech Republic. (Detailed comparison by means of HTC for the whole Czech Republic was elaborated by Dobrovolny 1996). The high values of HTC in 1997 correspond to the distribution of precipitation sums during the season (April - September).
5. WINE-GRAPE YIELDS DURING 1993 - 2002
Every year the agricultural crop yield serves us as one of the quality indicators. In the next table, there are shown the wine-grape yields during 1993-2002. (The values are calculated for the administrative units - Brno city districts, Brno - the City, Breclav, Hodonin, Uherske Hradiste, Znojmo, Vyskov and Kromeriz - Fig. 5)
Table 5: Wine-grape yield (t/ha) in the districts of Southern Moravia (by UKZUZ Brno)
District/year	1993	1994	1995	1996	1997	1998	1999	2000	2001	2002
Brno	4,17	5,70	3,86	5,59	3,23	4,64	6,75	4,47	4,62	4,90
Breclav	4,97	6,13	4,36	6,14	3,50	5,75	6,44	5,83	6,13	5,53
Hodonin	6,32	6,00	3,85	7,02	4,23	4,96	6,83	7,30	7,38	5,10
Kromeriz, Zlin, Vyskov	6,18	2,3	1,26	3,63	2,39	3,62	4,50	7,32	9,00	4,30
Uh. Hradiste	5,81	4,72	4,07	5,28	3,63	4,49	5,02	6,34	6,49	4,80
Znojmo	4,86	6,76	3,67	5,62	1,21	4,09	4,95	5,06	5,02	5,20
Total South Moravia	5,34	6,13	4,00	6,18	3,20	4,99	6,11	6,03	6,15	5,28
Figure 4: Administrative districts in the Southern Moravia
DISTRICTS IN THE SOUTHERN MORAVIA
It is obvious that the yields differed a lot in the course of the 1993-2002 decade. The lowest values occurred in 1997. The main cause of this fact were extremely low temperatures during winter 1996/1997 when the vineyards were damaged by frost. The next important reason was the course of meteorological elements during growing season. The distribution of precipitation in the period from April to September was described in the chapter 4.1. The
vegetative course of grapevine was normal until the flowerage. Frequent rainy periods caused bad blooming of grapevine in the second half of June. As a result the yields dropped off again. High precipitation sums caused an occurrence of Downy mildew of grapevine (Plasmopara viticola) in July. Mainly leaves and grapes were harmed. On the other hand, the precipitation did not practically occur in the second half of August (during the phenological stage called softening of berries) and the highest daily temperature reached the values over 30 °C. The course of meteorological elements was positive during the phenological stage of ripening. In this year it was one of the best quality harvest though being the lowest on the other hand. (The sugar content was very high, yield very low).
The development of HTC (Kucharovice and Dyjakovice stations) and wine-grape yields (Znojmo district) is shown in the next figure for comparison.
Figure 5: Wine-grape yields (t/ha, Znojmo district) and HTC in the course of summer months (Kucharovice and Dyjakovice stations) during the 1993-2002period
An enormous difference between the both characteristics in 1997 is obvious. On the other hand, the values of HTC were almost equal in 2002 but the yield, in this very year, did not drop off. It indicates that a suitable distribution of precipitation is more important for grapevine (during growing season) than the absolute sum of precipitation.
6. CONCLUSION
The author has placed special emphasis on the behaviour of the two most important meteorological factors concerning winegrowing - temperature and precipitation. The temperature characteristics in each of the Moravian winegrowing sub-regions differ a lot. The warmest locality (out of all selected stations) seems to be Velke Pavlovice where TS10 did not drop under 2700 °C in the chosen decade. The lowest values were measured at the
Kucharovice station (average TS10 was 2695.23 °C in the decade).
Precipitation and moisture conditions were described by means of absolute precipitation sums during the season (i.e. from April to September) and the Seljaninov's Hydrothermical Coefficient during the period from June to August. The values of HTC confirm the fact that the South Moravian region belongs among the most arid regions in the Czech Republic. The connections between wine-grape yield and the course of meteorological elements were discussed in the respect of the abnormal year 1997. The distribution of precipitation in the second half of June and in July was one of the main causes of the low yield in this year.
References
Antoš, O. (2004): Agroklimaticke podminky pestovani vinne revy na jižni Morave. [Diplomova
prace] Olomouc, Katedra geografie Pnrodovedecka fakulta UP Olomouc. Brazdil, R. - Rožnovsky, J. (1996): Impacts of a Potential Climate Change on Agriculture of the Czech Republic - Country Study of Climate Change for the Czech Republic, Element 2. Narodni klimaticky program ČR, svazek 21. Česky hydrometeorologicky ustav, Praha, 146 pp.
Dobrovolny, P. (1996): Possible changes in agroclimatic potential of the Czech Republic. In Climate Variability and Climate Change Vulnerability and Adaptation. Institute of atmospheric Physics, Praha, pp. 187-192. Vysoudil, M. - Jurek, M. (2004): Air Temperature in the City of Olomouc 1991-2000. Acta Universitatis Palackianea Olomucensis, Fac. Rer. Nat., Geographica 38. Published by the Palacky University Olomouc, Olomouc, pp. 93 - 98. ISBN 80-244-39-2, ISSN 02319365.
Vysoudil, M. - Jurek, M. (2005): Summer Air Temperatures in Ljubljana (Slovenia) and Olomouc (Czech Republic) in the Period 1961-2000. Dela 23. Geographical View of Regional Development. Department of Geography. Faculty of Arts, University of Ljubljana, pp. 245-258. ISSN 1854-1089 Reva vinna, revove vino. Situačni a vyhledova zprava. Listopad 1997. Ministerstvo zemedelstvi Česke republiky, Praha, 58 pp.
NEKATERE AGROKLIMATSKE ZNAČILNOSTI JUŽNE MORAVSKE (REPUBLIKA ČEŠKA) V OBDOBJU 1993-2002 POMEMBNE
za vinogradništvo
Povzetek
V prispevku so analizirane nekatere temperaturne in padavinske poteze Južne Moravske, ki so pomembne za uspevanje vinske trte. Analiza temelji na podatkih za pet reprezentativnih meteoroloških postaj v obdobju 1993-2002. Pri temperaturah je poudarek na analizi vsot povprečnih dnevnih temperatur višjih od 10 0C (TS 10) v obdobju april-september. Razmere glede teh vsot se v obravnavani pokrajini precej razlikujejo. Najugodnejše razmere so okoli
Velkih Pavlovic, kjer so vrednosti TS 10 večinoma nad 3000 0C. Najnižje vrednosti so v okolici Kucharovic, kjer je TS 10 v povprečju pod 2700 0C. Tudi najvišje vrednosti TS 10 0C na Moravskem so precej nižje od vrednosti v južnejših vinorodnih območjih, zato v severno ležečih, kamor se uvršča tudi Češka, za zagotovitev boljše kvalitete vin sadijo predvsem bolj zgodnje sorte trt.
Vlažnosti pogoji za uspevanje vinske trte so predstavljeni s količino padavin v rastnem obdobju (april-september) in s Seljaninovim hidrotermičnim koeficientom (HTC). Glede HTC ima Moravska še vedno humidno podnebje (HTC je nad 1), vendar sodi med najmanj namočene pokrajine Republike Češke. Temperaturni in padavinski pogoji so na splošno ugodni za gojenje vinske trte, vendar pridelek grozdja zaradi vremenskih razmer v posameznih letih zelo niha, prav tako tudi kvaliteta vin. Kot primer leta z netipičnim potekom vremena in posledicami le-tega za vinogradništvo, je predstavljeno leto 1997, ko je bil pridelek grozdja najnižji v obravnavanem obdobju. Skromen pridelek je bil posledica zimske pozebe, deževnega vremena v času cvetenj a vinske trte, vlažnega vremena in z njim povezanimi boleznimi vinske trte v visokem poletju ter suše v drugi polovici poletja. Kljub količinsko skromni letini pa je bila kvaliteta vin zelo visoka, saj je bilo vreme v času zorenja grozdja zelo ugodno.