Root-Symmetry of Conifer Plants in Field

1988

20 S.

7 Abb., 6 Tab., 28 Lit. Ang.

Bandaufführung

2693

11311

The relationship between the growing technique used in the nursery and the root development in the field have been discussed from time to time. Instability of contorta pine is regarded as a general problem, and instable Norway spruce plants were observed in commercial plantations in Norway thelast few years; the discussion about instability and growing technique was res umed. On this background, contorta pine and Norway spruce plants were dug from some experimental plantations originally designed to study effects on survival and growth of different growing techniques in the nursery. An insignificant number of instable plants were observed. A high frequency of plants with strong root asymmetry was observed, although root asymmetry could not be related to species or production technique. In a two- years-old plantation of contorta pine, the root area was higher and the root asymmetry stronger for root-pruned than forunpruned plants. These tendencies were stronger for plants pruned a week or tw o before planting than for plants pruned at the time of planting. In a seven-year-old plantation of Norway spruce, there was a tendency towards higher root area for plants grown in containers on raised pallets (air-pruned roots) compared to plants grown in containers on a sheet of plastic. The results of the investigation supported earlier conclusions: The frequency of instable Norway spruce plants is generally insignificant, and instability is more related to the planting technique in the field than to the production technique in the nursery.A higher frequency of instable plants should be expected in plantations of con torta pine than in plantations of Norway spruce.