Defra - Department for Environment, Food and Rural Affairs.

Science Search

Science and Research Projects

Return to Science Search homepage   Return to Project List

Parameterising the biology and population dynamics of weeds in arable crops to support more targeted weed management - AR0409

Description
Overall Objective: To provide the basic population dynamics parameters for ‘weeds’ of importance both for agriculture and for the wider environment.

The work aims to meet the general MAFF goal of minimising pesticide use. This goal is not being fully met, as, currently, many farmers tend to use herbicides over-cautiously, resulting in supra-optimal levels of control. The challenge as laid out in the ROAME A is to develop more integrated weed management strategies. This project addresses the specific issue of providing a better understanding of weed-crop competition and population dynamics.... to support rotational approaches to weed management that are both economically sustainable and reduce environmental impact’.

Information will be collected in five areas: seed dormancy, long-term seed persistence, seed losses post harvest (including predation), seed production, and seedling emergence.
The information will be gained from: data from previous research projects, literature searches (data mining) plus interactions with other UK weed research groups (e.g. HRI, SAC) and finally new research.
Weeds to be included will be those that have been identified as having beneficial effects on the environment by providing food for insects and birds (work to be based around fat hen, knotgrass, chickweed, scentless mayweed, annual meadow grass and groundsel). Some paper studies on the major weeds that ‘drive’ the majority of weed control decisions (wild-oats, black-grass, cleavers, bromes) will also be included.

The data generated in this programme will be used primarily in the competition and population dynamics models being developed in the associated programme ‘Modelling of arable crop/weed dynamics and competition’ and will form the basis of predictions of the longer-term behaviour of weeds. The information generated in this project will provide underpinning for the longer-term management of weeds and will identify the effects of agronomic practices on weed populations over time. Thus, it will give guidance to MAFF on the potential for managing weeds for biodiversity purposes and will assist the farmer/adviser in making decisions about reduced input weed management. Technology transfer will be enhanced by the inclusion of the information from this project in the MAFF funded SAPPIO LINK Weed Management Support System project.
This will provide a ‘vehicle’ for the introduction of these less intensive weed management systems for growers of the major UK crop – winter wheat.
Objective
Overall Objective: To provide the basic population dynamics parameters primarily for ‘weeds’ of importance for the arable environment and to link this with the already existing data for the major weeds (black-grass, wild-oats, cleavers). Initial analyses and interpretation will be done of the data collected.

1. Seed dormancy
To quantify the innate and, where appropriate, the secondary dormancy of the target * weed species and explore how this may be influenced by crop management.

2. Long-term seed persistence
To establish the seed decline rates of the target weed species and the impact of different crops and crop management

3. Seed losses – post-harvest (IN ASSOCIATION WITH READING UNIVERSITY)
To determine the extent and mechanisms of the decline in viable seeds from weed seed maturity and crop harvest to the time of the main cultivation

4. Seed production
To quantify the level of seed production by the target weeds in a range of crops

5. Seedling emergence
To quantify the effects of environmental factors that influence the emergence of weed seedlings, to provide support for the link between seed levels in the seedbank and seedling emergence.

* Target weeds. The project will endeavour to quantify parameters for the following species:
Biodiversity significant species: fat hen, knot-grass, chickweed, scentless mayweed, annual meadow grass and groundsel). Practical work will be needed for aspects of the biology of these species
Major arable weeds: wild-oats, black-grass, cleavers, bromes, (for these species no actual research is anticipated, as information already exists and only needs extracting/collating)
Project Documents
• Final Report : Parameterising the biology and population dynamics of weeds in arable crops to support more targeted weed management   (5344k)
Time-Scale and Cost
From: 2001

To: 2005

Cost: £1,011,227
Contractor / Funded Organisations
Rothamsted Research (BBSRC)
Keywords
Arable Farming              
Crops              
Farming              
Natural Resource Use              
Sustainable Farming and Food              
Sustainable Production              
Weed Control              
Fields of Study
Arable Crops