Perspective apple clonal rootstocks for intensive orchards

Abstract

Breeding work in the Michurinsk State Agrarian University (MSAU) is based on one of the eff ective strategies for producing high-quality planting material for establishment of intensive perennial fruit plantations – the use of apple varieties and clone stocks that are highly resistant to extreme factors and immune to diseases. As a result of many years of breeding work, the MSAU is the originator of 24 forms of clonal stocks (out of 46 forms allowed for cultivation in the Russian Federation) and the patent holder of 8 stocks. In 2018, 4 apple clonal rootstocks (70-20-20, 70-20-21, 71-7-22, 75- 1-62) were included in the State Register of Breeding Achievements admitted to cultivation on the territory of the Russian Federation. The main requirements for apple stocks for intensive orchards are high resistance to major environmental factors; suitability for intensive types of orchards; increased resistance to pathogens; good ability to vegetative propagation; lack of root shoots in the orchard; increase of productivity, early fruited varieties, quality of fruits. The advantages of planting material of apple trees on weak clonal rootstocks of the MSAU breeding are established: high compatibility of rootstocks with the best zoned and promising apple varieties; high frost resistance and winter hardiness of the root system, withstanding up to -16 °С – there are no foreign analogues on this basis; high resistance of stocks to the bacterial burn (unlike most foreign stocks); accelerated entry into fruiting, the onset of the period of commodity bearing fruit in the orchard on the 3rd ... 5th year; high productivity of commercial apple plantings in the conditions of Central Russia – an average of 25 to 40-50 tons / ha. For widespread introduction into production, the most studied clonal stocks of the MSAU breeding are recommended in Russia and in many countries of the world: the Paradizka Budagovsky (dwarf), 62-396 (half-dwarf), 54-118 (medium-sized). To increase the productivity and the resistance of plants and the eff ectiveness of Russian horticulture as a whole, it is necessary to create mother nurseries of apple rootstocks, free from harmful viral infections (repositories).