Changing of the flower bud frost hardiness in three Hungarian apricot cultivars

Abstract

Hungary lies near the northern border of the apricot growing area, so frost hardiness is a decisive factor for the reliability of production. Both the development and loss of frost hardiness take place gradually in the overwintering organs, depending on the hereditary traits of the cultivars and the prevailing environmental conditions. Among the overwintering organs the flower buds are the most sensitive to frost. The frost hardiness of the flower buds of three Hungarian cultivars (Ceglédi bíborkajszi, Gönci magyar kajszi and Rózsakajszi C. 1406) was determined using artificial freezing tests during the dormancy period in 11 years. Mathematical models were developed to describe changes in frost hardiness of the flower buds in each cultivar. Ambient temperatures have a significant effect on the hardening and dehardening of flower buds, so it is important to study this trait as many years as possible. Based on the 11 years data characteristic features of frost hardiness of 3 apricot cultivars could be described accurately. Based on the results obtained the hardening process in the flower buds of apricot cultivars can be divided into two distinct phases. Tendencies in the changing of frost hardiness of 3 studied cultivars were similar, but significant differences were detected between them.

Keywords

• overwintering organs
• lt50
• apricot
• mathematical model