Research Branch Report No. 103

Glyphosate for the control of competing vegetation in Pinus radiata plantations at Myrtleford.  G. Minko.  January 1978.  15 pp. (unpubl.)

SUMMARY

The use of glyphosate (as Roundup which contains 36% w/v glyphosate) to control competing vegetation was examined in areas cleared of indigenous vegetation one year before Pinus radiata establishment at Myrtleford, north-east Victoria. Roundup was applied by a hand pressure mister at 1.3 l and 2.6 l in 92 l of water (equivalent to 0.468 and 0.936 kg glyphosate) per ha. When applied to field planted P. radiata glyphosate killed nearly all seedlings, but when applied four weeks before planting seedling survival was not affected. One year after spraying height and diameter of seedlings were significantly greater on glyphosate treated plots.

Although applied at relatively low rates, glyphosate reduced the amount of reappearing vegetation, particularly Poa spp., for at least two years. In short term, spraying considerably reduced the amount of unwanted vegetation, but appeared not to substantially affect species dominance or diversity of the existing plant community.

The study has shown glyphosate to be suitable for use in plantation establishment where the plant community is dominated by Poa species.

Also published:

Minko, G. (1978)  Glyphosate for the control of competing vegetation in Pinus radiata plantations at Myrtleford.  Proc. 1st Conf. Counc. Of Aust. Weed Sci. Soc., Melbourne, 1978, pp. 304-16.