Evaluation of glyphosate and metsulfuron methyl for native forest bracken control in central Victoria.  I. B. Tomkins.  June 2000.  15pp. (unpubl.)

SUMMARY

The growth of bracken (Pteridium esculentum) in native forests can inhibit eucalypt regeneration after logging. Consequently, there is a need to test the effectiveness of different herbicides to control bracken in native forest situations.

This study evaluated the effect of four herbicide + surfactant treatments on bracken cover at Mount Disappointment, central Victoria. The herbicide treatments were applied with a hand-held boom in February 1997. The herbicide + surfactant treatments were:

1. glyphosate at 12 L/ha + Pulse Penetrant at 0.2%
2. glyphosate at 4.8 L/ha + Pulse Penetrant at 1%
3. glyphosate at 4 L/ha and metsulfuron methyl at 30 g/ha (Trounce) + Pulse Penetrant at 0.2%
4. glyphosate at 0.96 L/ha and metsulfuron methyl at 60 g/ha (Cut-Out) + BS-1000 at 0.1%

Application rates for glyphosate refer to the 450 g/L product. Application rates for metsulfuron methyl refer to 600 g/kg product.

The results showed that all treatments significantly reduced the number of bracken fronds that emerged during the winter and spring following the summer herbicide application. However, only treatments (a) and (b) significantly reduced the number of fronds that emerged during autumn. In addition, the success of treatment (b) indicated that the use of high levels of surfactant with a relatively low rate of herbicide can be effective for bracken control.

There are three recommendations arising from this study. They are:

1. Future research should focus on the impact of bracken control herbicides on eucalypt seedling survival and growth, as well as bracken cover.
2. The effect of broad-spectrum foliar herbicides on native forest understorey species should be investigated.
3. Glyphosate CT products (450 g/L) be used in preference to 360 g/L glyphosate products when combined with an organosilicone surfactant such as Pulse Penetrant.