CULTIVATION OF YOUNG APPLE-TREE PLANTS USING COMBINED METHOD
The aim of the research was to make the technology for accelerated production of branched apple-tree seedlings that combine the use of protected and open ground, bench grafting, dense planting patterns, and no-replanting of seedlings. One- and two-year-old seedlings of ‘Tellissaare’ apple-tree variety grafted on the rootstock 62-396 were studied in 2016-2018 in the arch greenhouses of the institute. During the first year, two planting patterns were studied - one-line pattern of 40 × 15 cm and three-line pattern of 40 + 20 + 20 × 15 cm. In late summer, the plastic film was removed from the greenhouses. In autumn, the plantations were thinned to the pattern of 80 × 15 cm. The following year, the two-year-old apple-tree seedlings were grown in the open ground. To estimate the effectiveness of the no-replanting system of growing seedlings, the control variant was laid. The number of branched plants in the first year in the planting pattern of 40+20+20×15 cm was 20 % lower than in the pattern of 40×15 cm; the length of the lateral branches per one seedling was also shorter in this variant. The experiments in 2018 showed that the two-year-old seedlings grown without replanting under the pattern of 80×15 cm were far superior in quality than the seedlings replanted in spring and grown in the same conditions. The height of not replanted seedlings exceeded that of replanted ones 1.8 times; their stem diameter was 1.6 times bigger. In the no-replanting growing system, the total increment in shoot mass and length was almost 10 times higher than in the system with seedling replanting! Experiments showed that in the first year the planting pattern of 40+20+20×15 cm yielded 146.7 thousand one-year-old seedlings per one hectare, and in the second year - up to 82.5 thousand two-year-old apple-tree seedlings of high quality. The planting pattern of 40×15 cm yielded 69.6 thousand seedlings per hectare in the first year and 82.9 thousand seedlings per hectare in the second year.