Sapropel as a substrate component for green cuttings of sea buckthorn

The purpose of the research is to study the effect of peat-sand substrate with the addition of sapropel on rooting and morphometric parameters of the root system of green sea buckthorn cuttings. The experiments were carried out in 2017-2019 at LLC "Garden Center of the Agrarian University", located in the Krasnoyarsk forest-steppe. The objects of study are cuttings of sea buckthorn varieties Alei (male type) and Dzhemovaya (female type). Propagation of sea buckthorn by green cuttings was carried out according to generally accepted methods. Cuttings were taken from mother plants in the I decade of July, root formation stimulator - indolyl-3-acetic acid. Rooting was carried out in a greenhouse with a fine spray of water. The basic substrate for rooting green cuttings consisted of a mixture of high-moor peat with pHH2O 3.1 with river sand in a volume ratio of 1:1 (control). To reduce the acidity of the substrate and saturate it with nutrients, sapropel from Maly Kyzykul Lake with pHH2O 7.4 was used in doses of 10, 15 and 20 t/ha. In some variants, ammonium nitrate was additionally added in a dose of 30 kg a.i. per hectare. On average, over the observation period, the highest rooting rate of cuttings was obtained when using a peat-sand substrate with the addition of sapropel at a dose of 20 t/ha and ammonium nitrate: 86.9 % of the planted cuttings took root in the Alei variety, 82.6 % in the Dzhemovaya variety, which is 30.1 and 34.7 %, respectively, higher than the indicators of control plots. Taking into account the biometric parameters of the root system of rooted cuttings showed that the formation of a root formation zone on green cuttings of both sea buckthorn varieties did not depend on the substrate used; the largest number and length of roots of the 1st order of branching were recorded in the block of variants with ammonium nitrate on the substrate with the largest dose of sapropel added. In all variants using sapropel, the number of nodule formations on rooted cuttings of both sea buckthorn varieties was significantly higher than the control values.