Influence of physical properties of substrates on rhizogenesis of black currant cuttings (Ribes nigrum L.)

The aim of the study was to assess the effect of the physical properties of substrates on the rhizogenesis of black currant cuttings. The experiments were conducted in the Krasnoyarsk forest-steppe at the Garden Center of the Agrarian University LLC in 2017–2019. The black currant variety Minusinskaya Stepnaya was propagated by green cuttings according to the generally accepted method of M.T. Tarasenko. One-year-old shoots were cut from mother plants in the first ten days of July, cut into cuttings with two internodes, kept for 12 hours in a solution of indole-3-acetic acid and planted in protected soil, maintaining a placement pattern of 7 × 7 cm. The basis for the formation of substrates is a peat-sand mixture, high-moor acidic peat (pH H2O = 3,1) and sand were used in a volume ratio of 1 : 1 (control). Sapropel (pHH2O = 7,4) was used at a rate of 10, 15 and 20 t/ha to neutralize peat acidity and enrich the substrate with nutrients. In some variants, ammonium nitrate was additionally added at a dose of 30 kg active ingredient/ha. The laid substrates were used continuously for three years. It was shown that the addition of sapropel at a dose of 20 t/ha and ammonium nitrate at a dose of N30 to a mixture of peat and sand promotes an increase in the rooting of cuttings to 86 %, a decrease in the density of the solid phase of the substrate to 2,57 g/cm 3 , the bulk density to 0,66 g/cm 3 and an increase in the total porosity to 74 %. A strong direct relationship between the physical condition of the substrates and the rooting ability of black currant cuttings (R = 0,85) has been proven, in which the value of total porosity has a significant effect on rhizogenesis (p = 0,043).