EFFECT OF ROOTSTOCK ON THE GROWTH AND YIELDING OF 'JOJO' PLUM TREES IN AN ECOLOGICAL ORCHARD

Abstract

In 2005-2009 period, in a 5-year-old ecological orchard, a study was conducted of the growth and yielding of 'Jojo' plum trees grafted on Myrobalan Plum seedlings and Wangenheim Prune seedlings. On both these rootstocks, the plum trees began to bear fruit already in the second year after planting. In the last three years they blossomed abundantly, but in 2007 there was no fruit crop to collect because all the flowers had been destroyed by spring frosts. The trees grafted on Myrobalan seedlings were growing markedly stronger than those on Wangenheim Prune seedlings, but the latter were more productive. The fruits were analyzed in terms of soluble solids content and total acidity. Some of the fruits in the ecological orchard were affected by brown rot disease (Monilinia laxa Aderh. et Uhl.). The type of rootstock did not have an effect on the degree of intensity of the disease, nor on the number of fruits with the larvae of the plum moth (Laspeyresia funebrana Tr.). The characteristic reddening of the flesh surrounding the stone, and of the stone itself, was found in this plum cultivar to occur more frequently on the trees grafted on Wangenheim Prune seedlings than those on Myrobalan seedlings. The study is in its initial stages and will be continued.