Modern biostimulants and growth regulators for nursery breeding in conditions of degradation and desertification

The results of testing the preparations «Biostim Start», «Kornevin», «Agrovit Core» on experimental samples of tree species growing in various districts of the Volgograd region for the period 2019–2021 are presented. The method of grafting into the cleft, simple and for the bark on the сaragana variety of the selection of the Federal Research Centre of Agroecology of the Russian Academy of Sciences has been tested. The objects of research were 10 species from the genera Populus, Gleditsia, Caragána, Tamarix, Robinia, Ulmus. It was found that the soil germination of gledichia vulgaris was the best in the variant with the introduction of the super fertilizer «Agrovit Core» at a dose of 5...90 g/m2. The best result was noted in the experiment with the use of the drug «Biostim Start» with different doses of application in poplar and Tamarix species, which showed a record increase in arid conditions (from 80 to 100 cm), which was 2 times higher than in control samples. It was determined that during cuttings, an increased dose of introduction of growth regulators and biostimulators can reduce the percentage of preservation and development of green cuttings of woody species. The best result is given (up to 70% survival rate of rootstocks of experimental plants), in particular, autumn grafting for bark — the best autumn preservation and gains with a rootstock thickness of 0,3...0,8 cm. For further breeding work and experiments on the breeding of new varieties, the best species were selected — Caragana arborescens Lam., Populus nigra L., Populus bolleana Lauche., Tamarix L., Gleditsia triacanthos f. Inermis L. They have shown the best results in the conditions of the sharply continental climate of the arid region and are suitable for agroforestry development of the territory of the Lower Volga region.