Growth losses in Pinus radiata stands unsprayed for Dothistroma pini

Over a period of 5 years a stand of P. radiata D. Don annually sprayed for protection against D. pini Hulbary showed 6.0 m super(2)/ha more basal area than unsprayed neighbouring stands. This difference arose from losses in diameter increment, as well as mortality, in the unsprayed areas. The growth of dominant trees in the unsprayed areas was not significantly affected. The standard operational treatment, spraying at the 25% level of green crown infection, was only marginally effective in preserving total basal area increment.