Quality of Apple Maidens as Influenced by the Frequency of Application of Different Fertilizers in the Organic Nursery − Preliminary Results

A study was conducted in an organic nursery, in 2010 and 2011, on the growth of scab-resistant maiden apple trees of the cultivars Topaz and Ariwa grafted on M.26 rootstock. The young trees were grown at a spacing of 25 cm × 1.0 m on a podzolic soil. On the basis of the differences in the thickness and height of the maidens, and the number of lateral shoots and their length, as well as the number of branched trees, the effects of various fertilizers were studied depending on the number of treatments applied to the plants, which were treated either once or twice with such products as granulated manure, Micosat, Humus UP, Humus Active + Aktywit PM, BF Amin, BF Quality, Tytanit and Vinassa. The control plants were not fertilized at all, or fertilized with NPK. The fertilizers were applied the first time to the soil and plants in the nursery in mid-May and the second time in early June. The results showed that using them in a double treatment did not result in improved plant growth in every case. Two applications of humic preparations, the so-called vermiculites (Humus UP, Humus Active + Aktywit PM with the addition of beneficial bacteria), BF Quality, and to some extent also BF Amin gave better results in terms of the quality of maiden trees than a single application of these products, whereas in the case of preparations such as Tytanit and Vinassa, treating plants with them for the second time did not result in a significant increase in the intensity of plant growth in relation to the plants treated only once during the early period of growth