Influence of prolonging fertilizers on the morphometric parameters of apple tree seedlings with a closed root system

The purpose of research is to study the effect of long-term fertilizers on the morphometric parameters of annual apple seedlings with a closed root system (CRS) in the conditions of the Krasnoyarsk forest-steppe. The method of propagation of apple trees is winter grafting. Before planting the grafts, long-acting fertilizers Osmocote and AVA were added to the peat substrate, and urea was also used in its pure form and together with the AVA fertilizer, which does not contain nitrogen. Experiment options: 1 - control (without fertilizers); 2 - urea - N50; 3 - AVA - P125K50; 4 - AVA - P125K50+N50; 5 - Osmocote Exact Standard - N800P450K300; 6 - Osmocote Pro - N850P550K500. The experiments were carried out in 2021-2023. The prevailing weather conditions during the growing season generally met the requirements of the crop under study, but in 2023 there was a moisture deficit at elevated air temperatures relative to the average long-term data, which was balanced by compensatory irrigation. Average long-term data on the morphometric parameters of the above-ground part of apple tree seedlings of the Pepinchik Krasnoyarsky variety with ZKS showed that the best result was obtained with the addition of Osmocote Pro to the peat substrate - the average shoot length was 34.8 cm, the total shoot length was 37.9 cm, which is higher indicators obtained from other experimental options. At the same time, the root system was branched with a well-formed root. To obtain standard annual apple tree seedlings of the Pepinchik Krasnoyarsky variety with ZKS in one growing season, it is advisable to use Osmocote Pro fertilizer at a dose of N850P550K500.