WINTER HARDINESS OF PLUM ON DIFFERENT ROOTSTOCKS IN WINTER 2002/2003 IN ESTONIA

In Estonia, critically low temperatures occur quite often.
The winter of 2002/2003 was cold.
The lowest temperatures of this winter were in late December of 2002 and early January 2003. On the 11^th of January, minimum air temperature fell to -32.5°C (at the snow level -37.6°C). Two plum cultivars, ‘Queen Victoria’ and ‘Kubanskaja Kometa’, grafted on 16 different rootstocks: ‘Ackermann’, ‘Brompton’, ‘Brompton S’, ‘G 5-22’, Prunus marianna ‘GF 8–1’, ‘Saint Julien A’, ‘Saint Julien GF 655/2’, ‘Saint Julien INRA 2’, ‘Saint Julien Noir’, ‘Saint Julien d’Orléans’, ‘Saint Julien Wädenswill’, ‘Pixy’, ‘Wangenheims’, Prunus cerasifera ‘Hamyra’, P. cerasifera myrobalana and P. cerasifera (local) planted in an experimental orchard at the Polli Horticultural Institute in spring 2001 were evaluated for winter hardiness.
Trees were rated for winter injury in June 2003. According to our results only minimal injury of trees was shown by ‘Queen Victoria’ on P. marianna ‘GF 8-1’ and ‘Kubanskaja Kometa’, both on ‘G 5–22’ and ‘Wangenheims’. It was noted that trees of ‘Kubanskaja Kometa’ on different rootstocks were damaged more seriously (average ratings from 4.8 to 6.3 points) than trees of ‘Queen Victoria’ (average ratings from 2.8 to 4.5 points). The most damaged was ‘Kubanskaja Kometa’ on ‘Pixy’ (6.3 points) and ‘Queen Victoria’ on ‘Hamyra’ (4.5 points). Flower buds of ‘Kubanskaja Kometa’ on all rootstocks were totally killed and no flowering occurred in 2003 while flower buds of ‘Queen Victoria’ on most rootstocks flowered a little and even formed some fruits.

VIII International Symposium on Plum and Prune Genetics, Breeding and Pomology

H. Jänes, L. Klaas, A. Pae

plum cultivars, rootstocks, winter injuries

https://doi.org/10.17660/ActaHortic.2007.734.38