Trials , results , knowledge gained
A number of techniques and pieces of equipment were trialed . These included :
• splatter gun treatment of rubbervine using Grazon ; and
• mechanical removal of dense rubber vine infestations using an Auscrimper sucker puller attached to a bobcat , predominately in riparian areas .
SPLATTER GUN
The splatter gun was trialed on dense rubbervine , in a hard to access area , using Grazon . A 30 – 45 per cent kill was achieved on larger plants , and 95 per cent kill on smaller plants .
AUSCRIMPER SUCKER PULLER ( TWEEZERS )
An initial creekline trial was undertaken on dense mature growth of rubbervine , lantana , prickly acacia and chinee apple .
This proved to be highly-efficient with a good operator and achieved a 99 per cent kill .
An additional tracked ( and airconditioned ) bobcat and another sucker puller were purchased due to the success of the trial work .
However , within three weeks of working in rocky areas , the set of tracks were badly worn .
The tracked bobcat was , however , more stable in rough areas .
The success of the “ tweezers ” has encouraged the engagement of a full time operator systematically working across paddocks removing scattered infestations and denser areas of weeds , particularly on creeklines and river country .
Approximately 1200ha was treated in late 2022 .
The tweezers were unable to remove plants under about 7mm thickness and some follow-up chemical treatment is required .
A pasture seed mix ( butterfly pea , green panic , Rhodes grass and a stylo ) was applied to heavily disturbed areas where there was little regeneration of desirable pasture plants .
Treatment can be applied throughout the year , with an increase in activity through the wet season when soil moisture is higher , moving to soils that hold more moisture into the dry season .
A trained operator minimises machinery breakdowns and also ensures plants are not missed and are removed properly .
KEY LESSONS LEARNED
• Splatter gun treatment with Grazon did not work well on rubbervine .
• There is virtually no impact on any non-target species with the sucker puller .
• A good soil moisture profile is desirable when using the sucker puller .
• Follow-up is critical after weeds are pulled .
• It is recommended to chemically treat plants when they are showing no signs of stress and ensure good leaf coverage .
• The tracked bobcat was more stable in rough areas , but needs steel tracks instead of rubber , as they wear too quickly .