A review of literature, reports and discussion with key informants was undertaken to look for evidence and opportunity for new ways to manage weeds that exploit plant and animal management. The review process focused on novel or innovative approaches to weed management from the perspective of viewing the weed as a potential resource rather than a liability. As such, the review does not include a detailed summary of the known approaches to weed management.
The most promising approaches to emerge from the review were:
Use of plant growth regulators to exploit plant species variation in phenology to selectively vary plant (weed) growth and quality and consequently increase grazing preference for weeds.
Supplements and/or provision of a range of plants available to livestock to influence acceptance of weeds through effects mediated by interactions with antinutrients, changing protein, energy or macro/trace mineral availability or other interactions.
Altering feed preferences of livestock through training which may be amplified through social learning (ideally with young animals) with the prospect of being fixed through epigenetic change.
Trampling by livestock.
The technical feasibility and likelihood of success of these weed control approaches were assessed by consideration of 12 attributes that covered the aspects of technical merit, time span and on-going duration of effects, range of geographic application and weed types, effects on livestock production, labour, infrastructure and cost. Three of the four weed control approaches were considered worthy of R&D investment with the top two approaches being
(i) use of plant growth regulators; and
(ii) altering feed preferences of livestock through training.
Trampling of weeds by livestock was not considered of sufficient merit and is not recommended for further consideration.