Pesticide Usage in Scotland: Local Authority Integrated Weed Control Survey - 2019

Executive summary

This report presents the results of a voluntary survey of weed control measures used by Scottish local authorities (LAs) in 2019. Of the 32 LAs contacted, herbicide use data were received from 27 and details of integrated weed management practices from 28. These LAs collectively represent 89 per cent of Scotland's land area and 92 per cent of the population and, as such, provide a robust overview of Scottish LA integrated weed management practices.

All responding LAs employed integrated control methods, adopting a combination of herbicide and non-chemical weed control strategies. The most commonly used non-chemical methods employed were mechanical control (cutting, strimming, flailing and mowing as well as weed brushing and ripping), hand weeding and supressing weed growth with mulches. Almost all respondents (96 per cent) also adopted weed prevention methods to reduce the need for control, including using mulches (93 per cent), replacing annual flower beds with perennial beds to reduce inputs (79 per cent), mapping and targeting areas where most control is needed (36 per cent) and resurfacing areas to reduce the need for control (32 per cent).

A range of reasons for using non-chemical approaches were reported, with the main drivers being concern about environmental impacts and a desire to reduce operator and public exposure to herbicides. Where herbicides were applied, all respondents stated that they took steps to reduce their use, primarily by evaluating whether there were alternative non-chemical control measures and by minimising and targeting herbicide use. The main reasons stated for choosing to use herbicides over alternative controls were for control of invasive weeds, maintenance of acceptable visual appearance and protection of infrastructure. Where herbicides were used, they were reported to be more effective over a longer period, with a lower associated cost, than alternatives. Some LAs also reported that there was limited availability of alternative control methods.

The surveyed LAs collectively applied 15.2 tonnes of herbicide active substance in 2019. Twelve active substances were used in total and, in common with other amenity use settings, glyphosate is the most widely approved and used herbicide (99 per cent by weight). Three LAs stated that they had prohibited or restricted the use of glyphosate on some surfaces in 2019/20 (during or after the survey data collection period). One further LA stated that they were currently reviewing their future use of glyphosate.

Where specified, most herbicide applications were by knapsack sprayer (58 per cent), vehicle mounted boom sprayer (18 per cent) and vehicle mounted lance sprayer (15 per cent). Where specified, 55 per cent of herbicide applications were to hard surfaces, 17 per cent to soft surfaces and 28 per cent to a combination of both.

Twenty four respondents (86%) stated that they planned to continue to reduce the amount of herbicide applied in the future and several stated they were currently exploring alternative methods of control.