Selection of Scots pine seedling growth stimulants in extreme conditions of the Northern Kazakhstan steppe zone

Abstract

The aim of this research is to determine optimal methods of using stimulants in a pre-sowing treatment of common pine seeds to increase their germination and obtain high-quality planting material. A study has been performed in forest nurseries of the State Forest Natural Reserve (SFNR) “Ertis Ormany” (Pavlodar region) and the Arykbalyk Branch of the State National Natural Park (SNNP) “Kokshetau” (Akmola region). The research is done with one-and two-year-old seedlings of ordinary pine sowing of 2017. A presowing seed preparation is carried out according to six options by using various types of stimulants. A method of mathematical processing of the thus obtained measurements of the seedlings with an insufficient number of measured plants is proposed by using a bootstrap analysis with and without quantile information. It allows one to estimate the influence of stimulants on the average growth of one-and two-year-old seedlings at a reliable level. As a result of these studies, it has been revealed that the pre-sowing treatment of pine seeds with ordinary stimulants increases the average height of annual seedlings. However, the results obtained in this experiment depend on the region of nursery location, but the use of soil irrigation with an “EridGrow” activator has increased the average height in both nurseries: by 13.9% in the “Kokshetau” SNNP for one-year-old seedlings, by 37.2% for two-year-old seedlings compared with the average height of the control seedlings. For pine seedlings in the “Ertis Ormany” SFNR nursery the influence of the stimulants is insignificant, but the positive effect on the average growth with the “EridGrow” soil irrigation is a 7.3% increase in the first year and a 24.7% one in the second year.