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- Level of threshold weed density does not affect the long-term . . .
It is shown that long-term application of thresholds results in a control frequency that is independent of threshold level, and in aperiodic dynamics of the weed population which may cause uncertainty about what control frequency and hence what costs of control are expected over a given period
- Weed Thresholds: The Space Component and Considerations for . . .
The most recent literature has focused of on weed control methods due to evolution of herbicide the interaction between weed population processes and resistance, are included in the threshold equation Even economic factors to define economic thresholds (2, 3, if 9, specific economic values cannot be associated with 26)
- Dynamics of weed populations : spatial pattern formation and . . .
The dynamics of a weed population subjected to such a 'threshold control programme' is characterized by aperiodic (quasi-periodic or chaotic) cycles, whereas the long-term herbicide use does not depend on the threshold value In the second weed control programme, the optimum herbicide dosage is determined and applied to the whole field
- Weed Thresholds: The Space Component and Considerations for . . .
As an extension of weed threshold models in which crop losses are based on weed density, an alternative model for grass weeds in cereal crops is proposed that incorporates the theoretical importance of selection for herbicide resistance, initial weed population frequency, and weed seed dispersal Simulations suggest optimum weed population levels (thresholds) for maintaining genotypes that are
- Weed control thresholds: a useful concept in natural ecosystems?
The general failure of control thresholds, based upon measures of weed impact, to deliver benefits in the management of agricultural weeds cer-tainly does not bode well for their applica-bility to natural ecosystems
- 5. 7 Critical Period of Weed Control – Principles of Weed Control
5 7 Critical Period of Weed Control Vince describes the idea of different thresholds, where some crops are able to tolerate more of one weed than another These thresholds come into play when a farmer is determining whether or not to apply additional weed control measures (and thereby, extra expenses) – weighing the benefits and the
- Level of threshold weed density does not affect the long-term . . .
A paradigm shift from thresholds to longer term population management is warranted and the principles of natural resource economics illustrate that including the intertemporal effects of weeds control will result in a greater level of weed control and a higher economic benefit than if control decisions were based solely on the current period
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