The 48th British Crop Production Council Annual Weed Review, chaired by Gordon Anderson-Taylor, Ph.D., Bayer CropScience, was held at PGRO, Peterborough, early this month. The review gathering of more than 60 scientific delegates addressed a wide range of issues affecting agricultural weed control in the United Kingdom.

A major presentation by Clare Butler-Ellis, Ph.D., from NIAB/TAG, noted how grass weeds are one of the biggest weed control challenges in arable crops. Part of the problem is the vertical nature of these weeds means that the target area is more difficult to hit with sprays.

In her presentation, Butler-Ellis outlined advances in application she offered as improved weed control especially on grass weeds. As reported from the conference, her points were how “getting a good deposition on a vertical target can be achieved by a slight wind, a forward speed and angling nozzles forward to give the droplets a horizontal velocity.” Volume is also important, but she referenced studies that were surprising because she said in some cases “higher volumes reduce the quantity of active ingredients impacting on the grass weed target in cereal canopies. There seems to be no advantage in applying more than 100 liters per hectare.

European Union pesticide legislation and directives continue to make headlines, and Ingrid den Hoed from CRD highlighted the impact of losing herbicides for use. She reported 74 percent of active ingredients have been lost under EU91/414 with 67 percent removed from the market and a further 7 percent not approved after recent review.

She outlined the legislation highly restrictive to active ingredients being on the market or new ones being developed for use.

“The potential impact of greater reliance on fewer actives includes the increased likelihood of resistance developing. Grass and broad-leaved weed control—especially in oilseed rape—will become increasingly difficult. New solutions need to be found, both chemical and non-chemical, and a more whole farm integrated approach to crop production adopted,” a report from the meeting noted.

Sarah Wynn, Farm Systems Consultant, ADAS, provided examples of problem weeds reducing yields and the income potential to growers. What is referred to as black-grass problems in oilseed rape could reduce yields by up to 1.2 tonnes per hectare due to the weed competition, and she also noted there would be a large increase in cost for using different herbicides, if they are even available.  

Just as in the U.S., the loss of glyphosate herbicide for use in crop production can drastically increase weed control costs. “If glyphosate were to be lost, severe financial losses to UK agriculture would result, especially in pre-planting use. Without glyphosate (vulnerable under the WFD-legislation), the loss of gross margin in wheat production in the UK could be up to 17 percent, oats up to 20 percent and oilseed rape up to 15 percent,” the review/meeting report explained.

The problem for growers is also a major problem and cost to the crop protection/herbicide manufacturer industry. Limiting business product sales encumbers these agricultural industry companies in being viable businesses in the UK and EU.

“Environmental stewardship herbicide choices” and new EU pesticide legislation is expected to hinder crop production, field margin, landscape and turf area weed control.  The report noted how Mike Green from Natural England said the future focus for environmental stewardship needs to be on quality rather than quantity in limiting herbicide use. There needs to be science for support and guidance rather than arbitrary further restrictions.

Ruth Mann, Ph.D., from STRI, highlighted a number of problems facing the turf and landscape industry. She outlined the sports turf/golf course specific weed control problems with limited herbicides.

The BCPC claims to have an international reputation for sound science in the fields of agriculture, food and the environment. Its conferences, publications and working groups bring together scientists to form opinion on key issues. Copies of the weed review presentations can be accessed on the BCPC website at: http://www.bcpc.org/report_48th-Annual-BCPC-Weed-Review_204.html