%0 Research article
%T Fifteen-year response of weed control intensity and seedling type on Norway spruce survival and growth on arable land
%A Hytönen, Jyrki
%A Jylhä, Paula
%D 2008
%J Silva Fennica
%V 42
%N 3
%R doi:10.14214/sf.242
%U https://silvafennica.fi/article/242
%X The effects of seedling type (2-year-old container seedlings vs.  4-year-old bare-rooted seedlings) and post-planting vegetation control  intensity on the growth and survival of Norway spruce (Picea abies (L.)  Karst.) seedlings were compared based on 15-year data from a field  experiment established on arable land. Vegetation control treatments  with terbuthylazine and glyphosate were carried out 1–3 times on  successive years, either as overall or spot applications. The highest  stand volumes were obtained with the combination of large bare-rooted  seedlings and effective vegetation control. Volume of  bare-rooted  seedlings  was greater  than that of container seedlings in all  treatments (e.g. on the control plots 9.5 m<sup>3</sup>/ha vs. 4.1 m<sup>3</sup>/ha).  The best results were obtained with the most intensive weed control  treatments (spot treatment repeated twice and overall application  repeated three times). These treatments increased both bare-rooted and  containerised seedlings’ survival by 33–40% units and their height,  breast height diameter, and volume by 45–49%, 17–47%, and 249–279%,  respectively. In terms of survival, the container seedlings, in due part  to their smaller size, benefited from vegetation control more than the  bare-rooted seedlings. Successive early summer frosts damaged the  seedlings and significantly retarded their growth. The frequency of  frost damage was not affected by vegetation control nor was it  attributed to seedling type.