Powerlink IVM trials
Experiments were undertaken in collaboration with Powerlink
to determine the potential benefits of the implementation of an Integrated
Vegetation Management (IVM) program into Powerlink operations.
Following on from the IVMP project, where certain plant
growth regulators were found to effectively suppress Bahia grass seed-heads for
11 weeks, a commercial demonstration was conducted within the boundaries of the
Mudgeeraba Substation during autumn 2010. In this demonstration, one of the
treatments provided a 70% reduction in grass seed-head production during the
entire observation period (i.e. 15 weeks). The period of suppression was
probably extended by the cooler weather towards the end of the trial and an
associated slowing of grass growth and seed-head production at this time.
This demonstration confirmed the results of the IVMP project
and showed that some benefit can also be gained during autumn, though the
benefit is not as great as during the height of summer. It showed that an IVM
program has the potential to reduce the cost of managing grassed areas in
Powerlink facilities by reducing the mowing frequency. More importantly, an IVM
program has the potential to reduce the number of interventions required in the
management of the vegetation at Powerlink sites.
Untreated area on the left has numerous seed-heads that require mowing, while the treated area on right does not require mowing.
Other areas within Powerlink facilities are required to be
kept maintained without any vegetation whatsoever. These "no vegetation
zones" surround vital equipment and are usually covered with concrete or
coarse gravel. They are currently sprayed with Glyphosate to control weed
species in an effort to maintain them free from vegetation.
This practice provides excellent control of the weeds
present, but does not provide substantial long-term control. For safety
reasons, such facilities have to be shut down every time that these vegetation
management activities are undertaken, thereby interfering with their normal
function.
Hence, an experiment was undertaken to evaluate the
effectiveness of two pre-emergent herbicides for the longer-term control of
weeds growing within areas of Powerlink infrastructure where no vegetation
growth is an essential requirement. These herbicides were compared to the
current standard practice of spraying with Glyphosate.
This experiment demonstrated quite clearly that the addition
of pre-emergent herbicides to a regular Glyphosate application can provide much
longer-term control. Seedlings were already quite abundant in the Glyphosate
treated areas at 6 weeks after application. However, in the areas treated with
Glyphosate and a pre-emergent herbicide, seedling growth was greatly inhibited
(i.e. significant numbers of seedlings were not present until 15-25 weeks).
The results indicate that the use of pre-emergent herbicides
in combination with Glyphosate will greatly increase the time period between
interventions in "no vegetation " zones. This may be of great benefit to
Powerlink operations, as it will require facilities to be shut down less often
for vegetation management activities to be undertaken. Back to news
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