Influence of Growth Stimulants on Seed Germination and Seedlings Growth of Scots Pine (Pinus sylvestris L.)

Scots pine (Pinus sylvestris L.) is a potential introduced plant that can be used for reforestation in the southern part of Primorsky Krai. This plant is valuable for water regulation and mountain strengthening. It is widely used in the national economy. However, the growing area of the stands reduces with logging. It is possible to speed up the regeneration process by applying growth stimulants. The purpose of this study is to investigate the impact of natural (Zircon, Ekopin, Ribav-Extra) and synthetic (Krezatzin, Epin-Extra) growth stimulants on seed germination and biometric parameters of annual and biennial Scots pine seedlings (height, root collar diameter, length of root lobes, and biomass). Before cultivation, the seeds were soaked for 1 hour in a solution of KMnO4 (0.5 %) followed by 20 hours in growth stimulant solutions with concentrations 1.4 & BULL;10-3 ml/l. The control group was presented with seeds without stimulant treatment. The soil germination was controlled on day 15. It was also determined the effectiveness of the stimulants as root top dressing for annual and biennial seedlings. The concentrations of the solutions were 0.2 and 0.1 ml/l with water as a solvent. The referentce group was seedlings without fertilization. Krezatzin, Ribav-Extra, and Ecopin had a significant impact on seed germination (92.7-94.0 %), exceeding the control group by 5.7- 7.2 %. Krezatzin, Ribav-Extra, Zircon and Ecopin were most effective for Scots pine seedlings. In the first year of growth, seedling height increased by 20.3-43.5 %, root collar diameter by 22.2-38.9 %, root lobe length by 23.5-52.9 %. In the second year, these indicators exceeded the control group by 18.4-75.5, 2.9-11.8 and 15.0-36.1 %, respectively. The biomass of biennial seedlings increased by 63.7-185.2 % compared to the control group with the use of these stimulants. The solution concentration of 0.1 ml/l was more effective. The biennial seedlings grown using the stimulants as root top dressing according to biometric indicators meet the requirements of the Reforestation Regulations 2020, significantly exceeding the values specified in them. These seedlings can be used for planting woodlands and landscaping in populated areas.