ORGANIC FARMING OF PLUMS IN ESTONIA

Mainly due to environmental reasons, the importance of organic farming in Estonia is growing. A new project with the aim to study plums in organic farming was started at the Polli Horticultural Institute in 1998. An experiment with five plum cultivars: ‘Emma Leppermann’, ‘Liisu’, ‘Ave’, ‘Perdrigon’ and ‘Queen Victoria’ was established in spring 1998. Trees of ‘Emma Leppermann’ served as controls. The trees came into bearing in the fourth year after planting. In 2002 and 2003, trunk circumference of five trees of each cultivar at 20 cm above ground level was measured and length of one-year-old shoots was determined. In both year, the yield per tree was calculated. Also the resistance to leaf spot was evaluated. No pesticides and fertilizers was used in that experiment. On the basis of these investigations, it was noted that trees of cultivars ‘Liisu’ and ‘Perdrigon’ have significantly smaller trunk circumference compared to trees of control cultivar. In 2002, the greatest mean shoot length was noted in ‘Ave’ and in 2003 in ‘Queen Victoria’. The best average yield per tree both in 2002 and 2003 was found in ‘Perdrigon’, 14.3 and 6.3 kg, respectively. The relatively resistant to leaf spot were cultivars ‘Ave’, ‘Liisu’ and ‘Queen Victoria’. On the basis of the preliminary results of the experiment, it can be concluded that plum is quite suitable for growing in organic farming.