Pear cultivar and rootstock research in northeastern Europe: an overview

Winter hardiness is the main factor limiting pear growing and the use of quince rootstocks under northeastern European climate conditions. Therefore, several cultivar and rootstock trials were performed from 1997 until 2015 at the Institute of Horticulture, Lithuanian Research Centre for Agriculture and Forestry. Investigations of pear cultivars were conducted in 2005-2015. Twelve cultivars on QS1 rootstock were tested with the goal of finding an optimal replacement for cultivar ‘Conference’, which is not sufficiently winter hardy in the Baltic countries. The cultivar ‘Mramornaja’ showed desirable characteristics based on winter hardiness, productivity and fruit quality. Rootstock breeding was based on a winter hardy Cydonia × oblonga population and resulted in 3 registered rootstocks of K series in Lithuania. K series rootstocks were compared with QMA, QMC, Sydo, QS1, and Pyrus × communis. According to tree growth control and productivity only K11 was equal to QMA and the same as QS1. Other rootstock testing included Cydonia and Pyrus clonal and seedling rootstocks. ‘Pyrodwarf’ and OH×F333 rootstocks were too vigorous. QMC, Sydo and BA29 exhibited poor winter hardiness. The search for both pear cultivars and rootstocks adapted to northeastern European climatic conditions must be continued.