Comparative Study on the Behavior of Some Old Apple Varieties before and after Their Grafting, with Potential for Use in Urban Horticulture

Abstract

Urban horticulture has to respond to several challenges, including reducing the growth vigor of the scion/rootstock combination, adapting the cultivated species/variety to the pedoclimatic conditions—more varied in recent years, and increasing tolerance to diseases and pests that cause extensive qualitative and quantitative damage to fruit production. For this experiment, 15 old apple varieties were chosen, all known and cultivated in the Banat area, which were grafted on the MM106 rootstock. Several parameters were analyzed that can be used for a relevant classification for planting them in limited spaces, such as in a private garden. Our research started 10 years ago and has already resulted in a doctoral thesis that extensively presents the data taken from the initial biological material and the first two years after grafting the trees; the research continued and is still ongoing in the experimental orchard. From the multitude of aspects studied, we have chosen to present some results related to the vigor of the scion/rootstock combination, the quality of the fruits, their content in acidity as well as the behavior with respect to diseases and pests—results that can be useful to those who want to grow old apple varieties in their own garden. Growth vigor was reduced in most varieties, but the highest influence of the rootstock on growth was observed in the ‘Bănățenesc’ variety, followed by ‘Jonathan de Munte’ and ‘Caslere’. Grafting and agrotechniques had a positive influence on the fruit mass in all cultivars, except ‘Crețesc’, with an experimental average of 163.35 g, namely 60.56 g higher on average than that of the original biological material. After grafting, the SSC was between 10.05 °Brix in the ‘Curcubătoase’ variety and 18.48 °Brix in ‘Parmen Auriu’, with an experimental average of 14.96 °Brix. The fruit acidity oscillated between 0.13 g/100 g in ‘Florănești’ and ‘Pătul’ varieties and 0.46 g/100 g in ‘Domnesc’, with an experimental average of 0.25 g/100 g.