Comparison of winter hardiness and growth of Actinidia arguta and A. kolomikta cultivars grown in central Poland

A field experiment with Actinidia arguta and A. kolomikta cultivars purchased from a commercial nursery was conducted in Skierniewice, central Poland. Both Actinidia arguta and A. kolomikta cultivars were planted in June 2005 at a spacing of 3 × 2.2 m. The aim of the study was to investigate the influence of climate conditions on the growth of eight cultivars of small kiwi fruit and to evaluate their usefulness for orchard culture in central Poland. After three years of growth in different climate conditions, including one of the coldest winters (2005/06) during the last years, and also severe late spring frosts (2007), some conclusion can be drawn. Two cultivars of Actinidia kolomikta have shown quite good resistance to winter and spring frosts, but the growth rate of these plants was rather slow. All the cultivars of Actinidia arguta were damaged by frost during the 2005/06 winter due to the snow-cover level, which was rather thick (24 cm). One year later all new shoots and leaves of Actinidia arguta cultivars were damaged completely by late spring frosts, which deleted flowering and fruit setting for at least one year. After three years of growth observations, the growth rate of small kiwi cultivars can be divided into three groups: fast growing with 'Jumbo' and 'Genewa'; moderate growing with 'Issai', 'Ken's Red' and 'Weiki' - male and female, and slow growing with A. kolomikta cultivars Dr Szymanowski and Sientiabrskaja