Growth parameters of coniferous planting stock influenced by principal growing technologies in Estonia

Abstract

The present research is a comparative analysis of how the main quality indices of containerized and barerooted planting stock (plant height, root collar diameter (RCD), and their ratio, above-ground biomass (AGB), below-ground biomass (BGB), and their ratio) conform to the existing planting stock standards in Estonia. Data were collected from nurseries in various state forest regions in 2001–2007. Containerized Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L).Karst.) seedlings were grown in Ecopot containers with 450 and 360 plants m⁻², and barerooted pine seedlings and spruce transplants were grown using the traditional field-grown technology, with 400 and 65 plants m⁻². The height of Scots pine containerized seedlings exceeded that of barerooted seedlings by 20% (p<0.05). The height of barerooted Norway spruce transplants exceeded that of containerized seedlings by 19% (p<0.05). The RCD of containerized pine stock formed 70% and the corresponding index of containerized spruce stock formed 48% of the RCD of the barerooted plants of the same species. The AGB of containerized spruce stock was on average 5.1 times smaller than that of barerooted transplants. The AGB of containerized pine stock was 1.9 times smaller than that of barerooted seedlings. The proportional development of various plant parts is also essential. It emerged that the BGB of 2-year-old barerooted pine seedlings was relatively small compared with their AGB (ratio 4.61), which may decrease plant establishment in cultivation. The ratio between the height and the RCD of containerized spruce stock was too high (7.9), making plants less resistant to external damage in cultivation.

Keywords:

• barerooted plants
• containerized plants
• Norway spruce
• quality of plants
• Scots pine

Acknowledgements

This study was supported by the Estonian Science Foundation (grant no. 4820), Estonian Environmental Investment Centre programme 07-06-8/255 and the Archimedes Foundation.