Evaluation of Walnut Tree Flowering and Frost Occurrence Probability During 1961-2012

0559884 - ÚVGZ 2023 RIV CZ eng J - Journal Article
Hájková, L. - Možný, M. - Dížková, Petra - Bartošová, Lenka - Žalud, Zdeněk
Evaluation of Walnut Tree Flowering and Frost Occurrence Probability During 1961-2012.
Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis. Roč. 70, č. 3 (2022), s. 235-248. ISSN 1211-8516. E-ISSN 2464-8310
R&D Projects: GA MŠMT(CZ) EF16_019/0000797; GA TA ČR(CZ) SS02030040
Research Infrastructure: CzeCOS III - 90123
Institutional support: RVO:86652079
Keywords : juglans regia * spring frost * phenology * minimum air temperature * czech republic
OECD category: Climatic research
Method of publishing: Open access
https://acta.mendelu.cz/artkey/acu-202203-0008_evaluation-of-walnut-tree-flowering-and-frost-occurrence-probability-during-1961-2012.php

Strength and direction of the potential effect of climate change on walnuts is regionally specific
(Gauthier and Jacobs, 2011) as climate change will probably affect the spatial distribution of the
walnut. This paper evaluated the long-term phenological series (1961–2012) of the beginning
of flowering, end of flowering and duration of flowering in walnut tree (Juglans regia) at two
phenological stations located in different geographical locations of the Czech Republic but in the
same climatic conditions (warm region). Phenological stages were analyzed in relation to growing
degree days and to spring frosts occurrence. Onset of the beginning and end of flowering occurred
earlier at Velké Pavlovice station (-2.1 and -1.3 days), and conversely occurred later at Doksany
station (+1.8 and +1.0). Period of flowering shortened at Doksany station (-0.8 day) and prolonged
at Velké Pavlovice station (+1.2 day). The occurrence of days with minimum air temperature < 0 °C
during walnut tree flowering was more frequent at Doksany station (in total, 29 days) with absolute
minimum value -5.5 °C. At Velké Pavlovice station 5 days with minimum air temperature below
0 °C were found during examined period with absolute minimum value -3.8 °C. The negative trend
in number of frost days occurrence during flowering period was found at both stations. Pearson
correlation coefficient between phenophase onset (and flowering period) and sums of growing degree
days was stronger at Velké Pavlovice station, and the highest value was between period of flowering
and temperature sums (0.782). The results confirmed our hypothesis of changes in phenophase
onsets and duration of flowering including spring frosts occurrence according to west-east gradient
(maritime climate-continental climate).
Permanent Link: https://hdl.handle.net/11104/0333012