The influence of meteorological factors on growth and vegetation process of Perilla frutescens (L.) Britton in Lithuania

Ona Ragažinskienė, Erika Šeinauskienė, Valdimaras Janulis¹, Lina Jankauskaitė¹, Arvydas Milašius¹

Kaunas Botanical Garden, Vytautas Magnus University, ¹Kaunas University of Medicine, Lithuania

Key words: Perilla frutescens (L.) Britton, growth, phenology, phases of vegetation period, climatic conditions of Lithuania.

Summary. The results of a study on the dependence of growth and vegetation process of Perilla frutescens (L.) Britton upon meteorological factors are presented in the article. The investigations were conducted at Kaunas Botanical Garden of Vytautas Magnus University during vegetation periods in 2001–2005. The object of investigations was Perilla frutescens (L.) Britton, a medicinal annual herbaceous plant of Lamiaceae Lindl. family, native of Eastern Asia, which passes the whole development cycle under climatic conditions of Central Lithuania. The duration of vegetation period of Perilla frutescens on the average is 167 days. The earliest beginning of vegetation and optimal climatic conditions for growth are when hydrothermic coefficient reaches 1.60–1.80 (conditions of excessive humidity). Optimal climatic conditions for massive flowering and seed maturation are observed when hydrothermic coefficient decreases to 1.20 – then massive flowering starts 10 days earlier and lasts 25 days longer. A strong correlation was found between massive flowering and hydrothermic coefficient (r²=0.9408). Using mathematical-statistical methods, the consistent patterns of growth and vegetation process of Perilla frutescens (L.) Britton were determined, specifying the time for raw material preparation what determines its quality and quantity.

Correspondence to O. Ragažinskienė, Kaunas Botanical Garden, Vytautas Magnus University, Ž. E. Žilibero 6, 46324 Kaunas, Lithuania. E-mail: o.ragazinskiene@bs.vdu.lt

Received 13 March 2006, accepted 1 July 2006