Preliminary results from new plum rootstocks trial in Estonia

For many years Prunus cerasifera Ehrh. seedlings of high vigour have been the most widespread seedling rootstock in Estonia. A trial of two plum cultivars 'Queen Victoria' and 'Kubanskaja Kometa' grafted on 16 different rootstocks: 'Ackermann', 'Brompton', 'Brompton S', G 5-22, 'P. marianna GF 8-1', 'St.Julien A', 'St.Julien GF 655/2', 'St.Julien INRA 2', 'St.Julien Noir', 'St.Julien d'Orleans', 'St.Julien Wadenswill', 'Pixy', 'Wangenheims', R cerasifera 'Hamyra', R cerasifera myrobalana and R cerasifera (local) was planted in spring 2001. The objective of this trial was to assess the behaviour of the new introduced plum rootstocks and to find out their compatibility with the plum cultivars. According to the results obtained in the first three growing seasons, 15% of the trees were very seriously damaged by low winter temperatures. The lowest trunk circumferences both of 'Queen Victoria' and 'Kubanskaya Kometa' were measured on 'St.Julien Wadenswill'. Trees of 'Kubanskaya Kometa' on different rootstocks started to bear fruit in the 2(nd) year after planting (except on R cerasifera 'Hamyra'). 'Kubanskaya Kometa' trees grown on 'St.Julien INRA 2' and 'St. Julien Noir' produced significantly better first yields than on control rootstocks. 'Kubanskaya Kometa' on 'St.Julien A' and 'Pixy' gave the largest fruits (41 and 40.5 g, respectively).