Five-year results from a blanking trial with Pinus patula

SYNOPSIS Five-year growth data are presented for a blanking trial with a third rotation Pinus patula crop measuring the effects of amount (25% or 50% blanks) and timing (2 and 11 months after first planting) of blanking. The blanking treatments achieved survival levels (range 81–90%) comparable to the control (85%) which was established without blanking. Blanks were generally smaller than originals, contributing mostly below average size trees and increasing overall stand variability. These effects were most pronounced when blanking 11 months rather than two months after planting of originals. Relative to the control, the treatments blanked after two months had comparable stand volumes but the 11 month blanking treatments had significantly reduced stand volume. The pattern of growth response to treatment of both blanks and originals suggests the inferior size of blanks results from competition effects between blanks and originals as well as simply the younger age of blanks. Should the increased proportion...