DYNAMICS OF APPLE TREE YIELD IN INTENSIVE ORCHARDS OF CENTRAL RUSSIA

The long-term research on the fruiting dynamics of apple trees grown in an intensive orchard on a dwarfing ‘Budagovsky Paradisk’ rootstock for the first 10 years of fruiting is presented. On average, over the research years, the yield of apple trees in 6 cultivars amounted to 26.8 t/ha. The highest average yield was in the ‘Ligol’ cultivar (38.3 t/ha), significantly higher (by 45.6 %) than in the control ‘Lobo’ cultivar (26.3 t/ha). The lowest yields were in the cultivars ‘Spartan’ and ‘Berkutovskoye’ (22.1 and 21.5 t/ha, respectively), significantly lower than in the control (by 16.0 and 18.3 %, respectively). The ‘Honey Crisp’ and ‘Alva’ cultivars formed yields at the level of the control cultivar. A regression dependence of the increase in the yield of 6 apple cultivars in an intensive orchard over 10 years of fruiting with a correlation coefficient r = 0.75–0.93 was established. For the first 6 years of fruiting, on average, the yield of apple trees of 6 experimental cultivars increases from 1 to 25 t/ha, and in subsequent years of observation it stabilizes and varies in the range of 25–35 t/ha depending on the weather conditions during the year. The nature of the dependence of the apple yield on age in the range of 1–10 years on average for 6 cultivars is approximated by polynomial regression equations with determination coefficients of medium and high degree R2 = 0.60–0.86. The variation of the equation coefficients is due to the genotypic specificity of the fruiting cultivars. The use of such fruiting models makes it possible to predict the average annual yield of an intensive apple orchard during the age periods of increasing yields and during the period of full fruiting.