Weeds

An EU-wide network to support and promote solutions for alternative weed control.  

ADAS scientists help evidence and guide crop disease management by chemical, genetic and biological approaches. Our expertise covers all areas of disease management on the major crops. We lead multi-organisation collaborative research into disease management and preventation, as well as provide strategic consultancy.  

This field lab was initiated as part of the ADAS project ‘Investigating the distribution and presence, and potential for herbicide resistance of UK brome species in arable farming’, funded by AHDB.  

App and website dedicated to pest, disease & weed identification and management.

Online guide to identifying arable weeds from ADAS, AHDB and BASF

TALISMAN and SCARAB were long-term projects developed to follow on from issues raised in the Boxworth project. TALISMAN focused on the economic issues of reducing pesticide and fertiliser use, whilst SCARAB examined the ecological side-effects of pesticides.

AHDB Guide from 2021 incorporating WRAG guidelines. Weed control is vital for high yields of good-quality crops and to prevent the spread of pests and diseases, e.g. ergot. Yet with fewer active ingredients, a need to protect water and manage herbicide resistance, the weed challenge must be managed across the rotation.

This Open Access chapter describes the current status of IWM for grasslands. Its focus is on management practices available to influence transitions in a weed’s life cycle: from the soil seed bank to seedling establishment, from the seedling stage to the mature plant, and from the mature plant to the soil seed bank.

The Weed Resistance Action Group (WRAG) produces guidance on pesticide resistance issues. Hosted by AHDB, this information can be used to help protect crops and the long-term efficacy of herbicides.

An ADAS report to DEFRA in 1998 highlighting key trends and research priorities for the sunflower industry in the UK Sunflowers (Helianthus annuus var. macrocarpus) are in high demand due to the culinary, confectionary, bird-seed and industrial uses of their seeds (and thus oils), in addition to the popularity of the flowers in horticulture. At the time of this report in 1998, the UK imported ~350,000 tonnes of seed annually.  Whilst sunflower can be grown in the UK, there are a number of challenges including limited drilling dates to comply with soil temperature requirements, and careful monitoring of a range pests and diseases that sunflower is susceptible to. Further risks such as a late harvest time and the possibility of sunflower itself becoming a weed in following crops meant many farmers were not considering growing sunflowers on their farms. Based on a survey of UK farmers (including both sunflower growers and non-growers), the key factors reported that would encourage more UK farmers to adopt sunflower crops were… To convince farmers of profitability Guaranteed establishment of the crop Earlier harvests Good disease and weed control More information on growing the crops This project provided a comprehensive review of growing sunflower as an arable crop in the UK.  You can find the entire report linked at the bottom of this article (including historical and market information on sunflowers) but some of the key sections are highlighted here. Note all information is accurate for the time of this report (1998).

AHDB Guide published in 2018.

Innovative Farmers are launching a new field lab exploring the use of poly cropping, inoculants and undersown cover crops to control blackgrass (BG) in spring and winter-sown crops.  

A 1998 study commissioned by the Pesticides Safety Directorate to assess the non-target impacts of pesticides on non-target terrestrial plants (NTTP's).  'To conserve and enhance biological diversity within the UK' was a stated aim of of the UK Biodiversity Action Plan (1994). Over 25 years later this is still a vital issue and the UK has stated its commitment to secure a post-2020 Biodiversity Framework as well as developing a 10 point plan for financing biodiversity (UK Government, 2022). However, a threat to plant biodiversity is non-target effects of pesticides - this is when pesticide materials reach areas beyond the target application area and affect the species there. Effects of pesticides on non-target plants can range from lethal (death of the plant) all the way to enhanced growth of these plants. Such varied effects depend on a range of things including the type of pesticide used, the concentration of its active ingredient and the sensitivity and spatial range of affected plants. Importantly, plants are part of complex food and pollination webs and so pesticide effects on plants can have cascading effects on the fauna that rely on them, and vice versa.

As grass-weed herbicide options in oats are limited, it is especially important to use integrated pest management (IPM). Organic systems, with their focus on cultural control – use of rotation, stale seedbeds and mechanical weeding – provide valuable lessons for control in conventional crops.

Harvest Weed Seed Control (HWSC) A project to explore harvest weed seed control (HWSC) under UK conditions as a method to control grassweeds and reduce the dependence on chemical control, particularly glyphosate.

This guidance provides an easy reference to the major broad-leaved and grass weeds in the UK, including how to identify and manage them based on an understanding of their biology.

A new paper published by ADAS summarises evolving black-grass herbicide resistance over the last 35 years, including the effectiveness of the dwindling actives left, and the vital role of routine resistance testing.

Written By James Clarke - ADAS Research Director

COVER CROPS USE ACROSS EUROPE

Docks are perennial weeds that compete with forages of nutritional importance for livestock production.

Biofumigation involves incorporating brassicaceous cover crops into the soil.

PGRO Chief Executive Roger Vickers talks us through one of PGRO's intercropping trial plots.

Creeping thistle has become an increasing problem especially for organic arable farms with soils of higher organic matter content.

Root structures and genetics give the weed an advantage over wheat and explain field patches.  

Monday 10th June - AM session only Monday 1st July - AM and PM session

Multi-species grassland leys in crop rotations can improve soil quality and nutrient efficiency, particularly with legume inclusion, which enhances nitrogen availability and reduces the need for mineral fertilisers. 

This report is a comprehensive literature review of weed control options, on a national and international level, that could benefit UK crop production in horticultural crops, cereals and oilseeds, sugar beet, potatoes, grassland, legumes and maize

Intercropping, sometimes known as polycropping, is the practice of growing two or more plant species simultaneously in the same field. 

This site offers free access to Proceedings from over 50 years of BCPC Conferences and Symposia dating all the way back to 1954; over 100 Technical Reports from the Weed Research Organization; and the WRO Annual Reports which include reports from each research section of the WRO.

Published in 1999, this report forms part of the work associated with the Integrated Farming systems (IFS) project (1992-1998). The aim of the study was to determine whether there is any difference between the riskiness of IFS and conventional systems in terms of spring spraying opportunities and its effects on production and the environment.. Herbicides were chosen as the 'role model'. The study looks at spraying opportunities and requirements at IFS sites (Hampshire, Cambridgeshire x 2, Herefordshire, Yorkshire and Midlothian. It seeks to apply the rotations to 2 different sized farms of 200 and 350 hectares and finally looks at the risk implications of each situation.  

 Weeds represent a significant and ongoing constraint to horticultural production.  This report 1. reviews the known effects of herbicides on weed populations within horticultural crops and the consequent indirect effects on fauna; 2. summarises the impact of weeds on horticultural crops; 3. Assesses perceived beneficial effects of weeds on the biodiversity of horticulturally based agro-ecosystems