The Effect of Tray Volume and Spacing on the growth and Development of Pinus radiata Seedlings

SYNOPSIS The effect of increased collar diameter on subsequent field growth of open-rooted pine seedlings is briefly described and the possible implications for the South African forest nurseryman discussed. The use of trays larger than the Speedling 128 can increase the collar diameter of the plants and at the same time reduce the period in the nursery to produce the required size. Increased spacing within the tray sizes adversely affected growth, presumably because of an inadequate moisture regime. Nurserymen are recommended to use the 98 Speedling tray or its equivalent and foresters are requested to set a minimum collar diameter of 3,5 mm when placing orders.