Scientific Reports of the National University of Life and Environmental Sciences of Ukraine

The article is devoted to the investigation of the influence of mulching materials on the yield and quality of the layers of apple-tree clonal rootstock M.9 and 54-118 types. Propagation of planting material for intensive apple orchards is based on high-quality vegetatively propagated rootstock material, which is obtained from the mother plants. High efficiency of mother plants is achieved by hilling with an organic substrate, which contributes to a higher yield of rootstocks with the highest commercial quality. Since the sawdust requires an annual update, it is relevant to find a substitute for it and reduce its use, in particular through the use of polyurethane pellets. Hilling of the mother plants of apple rootstocks with a mixture of sawdust with 25–50% of granules provides a better result compared to the soil. In 2012-2014 the research was conducted in the training and production department of Uman National University of Horticulture. In 2002 the mother plantation of rootstock M.9 was laid down (54-118 in 2010) with the virus-free plants in the way of horizontal layers with the scheme of planting 1.4 x 0.33 m. The influence of a mixture of hardwood sawdust (with the exception of oak) with the addition of 25, 50 or 75% of foam-polystyrene granules with a diameter of 0.3–0.8 cm on the yield and quality of the layers was studied. The maximum total yield and standard layers output of the rootstock M.9 are achieved on a substrate with a 25% granule content. With an increase in the content of granules in substrate, the yield of standard layers decreased. The use of 50–100% of granules in the substrate for the first hilling provided a significantly higher yield of first-grade layers. The dependence is non-linear with a maximum at 75% granule content. The maximum yield of second-grade layers was obtained using a substrate with a 25% granule content, with a tendency to decrease with an increase in the proportion of granules in the substrate. The maximum total yield and standard layers output of the rootstock 54-118were achieved on a substrate with a 50% granule content; and with an increase in the proportion of granules, the output decreased. Hilling with a substrate with a 25–75% granule content provides a significantly higher yield of first-grade layers, and with a 25–50% granule content the output of second-grade ones was higher

rootstock, standard layers, commercial grade, substrate