Pesticide usage in Scotland: Arable Crops and Potato Stores 2024

General trends

Crop area

In 2024 the census area of arable crops grown in Scotland was 502,359 hectares. This represents a 3% increase in cropped area since 2022 and a 1% increase from 2020. Since the last survey, areas of legumes, spring barley, seed potatoes, ware potatoes, spring oats and oilseeds have increased (14%, 9%, 8%, 7%, 4%, 3% respectively) while wheat, winter rye, winter oats and winter barley have decreased (8%, 8%, 4%, 3% respectively) (Figure 1 and 2). The wet weather in autumn 2023 resulted in a decrease in the area of winter sown crops and an increase in spring sown crops [7].

Figure 1 footnote: Triticale and mixed grain have been excluded as these represent < 500 ha. Source - June Agricultural Census. Note there was no June Census in 2022, therefore areas in this year were taken from Single Application Form (SAF) data – see the 2022 report for full details.

Cereals accounted for 86% of the total arable area (spring barley 51%, wheat 20%, winter barley 9%, spring oats 4%, winter oats 2% and winter rye 1%). Oilseeds accounted for 7% of the total arable area, potatoes 6% and legumes less than 1% (Figure 3). For full details of census crop areas, see supporting documentation Table 14. The largest area of arable crops was in the Aberdeen region, followed by Angus, Tweed Valley and Moray Firth (Figure 4).

Figure 2 footnote: Oilseeds include winter and spring oilseed rape and linseed, legumes include field beans, dry harvest peas and lupins. Source - June Agricultural census. Note there was no June Census in 2022, therefore areas in this year were taken from Single Application Form (SAF) data – see the 2022 report for full details.

Figure 3 footnote: Cereals include winter and spring barley, wheat, winter and spring oats, winter rye, triticale and mixed grain; potatoes include seed and ware potatoes; oilseeds include linseed, winter and spring oilseed rape; legumes includes field beans, dry harvest peas and lupins. Source - June Agricultural census.

Figure 4: Bar chart showing the regional distribution of arable crops grown in Scotland in 2024. 24% of crops were grown in Aberdeen, 20% in Angus, 12% in Tweed Valley, 11% in Moray Firth, 10% in Central Lowlands, 8% in Lothian and in East Fife, 3% in Solway, 2% in Caithness and Orkney and 1% in Southern Uplands and Highlands and Islands.

Pesticide usage

In 2024, as in 2022, the majority of arable crops (98%) received a pesticide treatment.

Winter and spring barley, winter wheat, winter oats, winter rye, oilseeds, seed and ware potatoes had the highest overall proportion of crop treated with a pesticide (between 98% and 100% Table 1). Spring oats and legumes had lower proportions of treated crop area (83% and 78% respectively). The average number of sprays applied to treated arable land, excluding seed treatments, was 4.0, very similar to that recorded in the 2022 survey of 4.1 sprays. Ware potatoes and seed potatoes received the highest average number of sprays (13.5 and 10.7 respectively), while spring barley, legumes and spring oats received the lowest (2.6, 2.6 and 2.8 respectively, Table 1). These figures only apply to the treated area of crops.

It is estimated that the area of arable crops treated with a pesticide formulation in 2024 was ca. 5,003,000 hectares compared with ca. 4,685,000 hectares in 2022 and ca. 4,793,000 hectares in 2020 (Table 10, Figure 5). This represents an increase of 7% from 2022 and 4% from 2020.

Figure 5 footnote: Sulphur and fungicide/growth regulator mixed formulations have been excluded as their use represents < 15,000 hectares.

In terms of weight of pesticide applied, it is estimated ca. 1,300 tonnes were applied in 2024, representing an increase of 7% from 2022 and a decrease of 6% from 2020 (Table 10, Figure 6).

Figure 6 footnote: Molluscicides, insecticide/nematicides and fungicide/growth regulator mixed formulations have been excluded as they represent < 10 tonnes.

In order to make accurate comparisons between the 2024 data and the data collected in previous surveys, it is important to take into account the differences in crop area between survey years. Therefore, the number of treated hectares per hectare of crop grown and the total weight of pesticide used per hectare of crop grown were calculated. In 2024, for each hectare of crop grown, 10.0 pesticide treated hectares were recorded. This represents an increase of 4% from 2022 to 2024 and an increase of 3% from 2020 (Figure 7). The estimated weight of pesticide applied per hectare of crop grown in 2024 was 2.6 kilograms. This represents an increase of 4% from 2022 and a decrease of 7% from 2020 (Figure 8). Therefore the overall pesticide use was broadly similar to that reported in the previous surveys in 2022 and 2020 (within precision estimates - relative standard errors). However, despite little overall variation in pesticide applicaton pesticide use in 2024 may have been influenced by several complex factors such crop composition and more favourable climatic conditions for pests, weeds and diseases in 2024. The 2023/24 growing season was challenging. Autumn storms of 2023 resulted in a decrease in the area of some winter sown crops grown and an increase in spring sown crops. Spring crops generally receive fewer pesticide applications. Winter and spring were 25% wetter, summer 50% wetter, and spring mean temperatures were 8% higher in 2024 than in 2022 [5] resulting in more favourable conditions for pests and pathogens. However the persistent rain and windy conditions also limited opportunities to apply sprays. As a result, there were some variation in spray timings and some complex tank mixes applied to minimise the number of passes required on fields [6]. The wet conditions also impacted harvest with delayed crop ripening. August 2024 had 21 wet days compared to 12 days in 2022 [5]. These wet conditions are likely to have influenced the increased use of desiccants prior to harvest [8].

Figure 7 footnote: Sulphur and fungicides/growth regulators mixed formulations are not shown as these represent < 0.1 treated hectares per hectare of crop grown.

Figure 8 footnote: Molluscicides, insecticides/nematicides and fungicides/growth regulators mixed formulations are not shown as they represent < 0.02 kg per hectare of crop grown.

Figure 9 footnote: Sulphur and fungicide/growth regulators mixed formulations have been excluded as their use represents < 0.5% of area treated.

Figure 10 footnote: Insecticide/nematicide and fungicide/growth regulator mixed formulations have been excluded as their use represents < 0.5% of weight applied.

Fungicides

In 2024, as reported in previous surveys, fungicides were the most frequently used pesticide by area treated, followed by herbicides/desiccants and growth regulators (Figure 5). Fungicides accounted for 45% of the total pesticide treated area and 49% of the total weight of pesticides applied (Figures 9 and 10). When changes in crop area are taken into account, the area treated with fungicides was similar in 2022 and 2024 and increased by 4% between 2020 and 2024 (Figure 7). From 2022 to 2024, there was a 3% increase in the weight of fungicides used per hectare of crop grown and a decrease of 3% between 2020 and 2024 (Figure 8). The principal fungicide mode of action on arable crops in terms of area treated continues to be sterol biosythesis in membranes, which includes the azoles (supporting document Table 5).

Herbicides/desiccants

In 2024, herbicides/desiccants accounted for 30% of the total pesticide treated area and 32% of the total weight of pesticides applied (Figure 9 and 10). When changes in crop area are taken into account, there was a 13% increase in area treated with herbicide/desiccant formulations from 2022 to 2024 and a 4% increase from 2020 to 2024 (Figure 7). In terms of weight of pesticide applied, when area of crop grown is taken into account, there was a 10% increase from 2022 to 2024 and a 11% decrease from 2020 to 2024 (Figure 8). In 2022 there were prolonged dry conditions resulting in low weed pressure and hot, dry weather at harvest time which reduced the need for the use of a desiccant with crops ripening naturally [3]. In contrast in 2024, winter and spring were 25% wetter, summer 50% wetter, and spring mean temperatures were 8% higher than in 2022 [5]. The harvest period in 2024 was wet in most regions and challenging for growers. The slow ripening of crops increased the need for the use of a desiccant [8]. The use of the herbicide/ desiccant glyphosate increased by 58% by area treated and 45% in weight applied from the previous survey in 2022 (Table 8 and 9).

Growth regulators

Growth regulators accounted for 11% of the total pesticide treated area and 15% of the total weight of active substances applied (Figures 9 and 10). When changes in crop area are taken into account, the area treated decreased by 7% from 2022 to 2024 and increased by 8% from 2020 to 2024 (Figure 7). The weight of growth regulators applied per hectare of crop grown decreased by 3% from 2022 to 2024 and 2% from 2020 to 2024 (Figure 8).

Seed treatments

Seed treatments accounted for 9% of the total pesticide treated area and less than 1% of the total weight of active substances applied (Figures 9 and 10). When changes in crop area are taken into account, there was a 4% increase in area treated between 2022 and 2024 and a 5% decrease between 2020 and 2024 (Figure 7). The weight of seed treatments applied per hectare increased by 4% from 2022 to 2024 and decreased by 14% from 2020 to 2024 (Figure 8). The slight increase in the use of seed treatments between 2022 and 2024 is predominately from the increased use of ipconazole and imazalil on cereals (55% and 51% increase in area treated respectively). The decrease in seed treatments over the longer term may relate to the withdrawal of some seed treatments such as thiram, pencycuron and penflufen (withdrawn in January 2020, March 2020 and June 2021 respectively).

Insecticides/nematicides

Insecticides and nematicides accounted for 4% of the total pesticide treated area and less than 1% of the total weight of pesticides applied (Figures 9 and 10). When changes in crop area are taken into account, there was a 12% increase in the area treated with insecticide/nematicide formulations from 2022 to 2024 and a 4% increase from 2020 to 2024 (Figure 7). In terms of weight applied per hectare of crop grown, there was a 22% increase from 2022 to 2024 and a 39% decrease from 2020 to 2024 (Figure 8). This increase in both area and weight from 2022 to 2024 is correlated with an increase in the number of insecticide applications on seed potatoes (7.2 applications in 2024 compared with 5.4 applications in 2022). Aphid borne viruses in Scottish seed potato crops have increased in recent years. As in 2022, lambda-cyhalothrin (pyrethroid) was the the most used insecticide active substance in 2024.

Molluscicides

Molluscicides accounted for 1% of the total pesticide treated area and less than 1% of weight (Figures 9 and 10). When changes in crop area are taken into account, the area treated between 2022 and 2024 was very similar, and there was a 27% decrease between 2020 and 2024 (Figure 7). The weight of molluscicides applied per hectare of crop grown increased by 4% from 2022 to 2024 and decreased by 26% from 2020 to 2024. The decrease in area treated and weight applied of molluscicides since 2020 is influenced by the withdrawal of the active substance metaldehyde in March 2022. The only active substance available to use for slug control in the 2024 growing season was ferric phosphate.

Sulphur

Sulphur accounted for less than 0.5% of the total pesticide treated area and 2% of the total weight of active substances applied (Figures 9 and 10). When changes in crop area are taken into account, there was a 24% decrease in area treated from 2022 to 2024 and a 14% increase from 2020 to 2024 (Figure 7). The quantity of sulphur applied per hectare of crop grown decreased by 7% from 2022 to 2024 and decreased 46% from 2020 to 2024 (Figure 8). Sulphur, applied primarily to cereals, is a multisite alternative to fungicides and was used for disease control and applied as a foliar feed.

Notable changes to individual active substances

As well as changes in overall trends in application of pesticide groups since the previous survey, there has been variation in the use of individual active substances. Five active substances were recorded for the first time in the 2024 arable survey (Table 4). These included the fungicides potassium phosphonate, pydiflumetofen, isoflucypram and valifenalate and the herbicide cinmethylin. The active substances cinmethylin, isoflucypram and pydiflumetofen have all been approved in GB since the previous survey (approved in July 2022, October 2023 and April 2024 respectively) and are yet to be approved in the EU. Potassium phosphonate is formulated in a new product with ametoctradin for blight control on potatoes. Its use may increase in future following the loss of mancozeb in November 2025. The area treated with the insecticides spirotetramat and flonicamid, both used on potatoes to control aphids, increased by 5,351% and 119% respectively. Aphid borne viruses in Scottish seed potato crops are known to be increasing in recent years, including new varients of potato leaf roll virus (PLRV) [9], and may be influencing the increase of insecticide applications. The use of the herbicide/desiccant glyphosate increased by 58% by area treated and 45% in weight applied from the previous 2022 survey. As discussed previously, the wet season in 2024 and the slow ripening of crops increased the need for the use of a desiccant. In terms of area treated, fluroxypyr was the most used herbicide in 2024. As mentioned, winter 2023 and spring and summer 2024 were 25 to 50% wetter than 2022 increasing weed pressure. The use of the fungicide fluazanim increased by 88% in area treated and 55% by weight applied. Fluazinam is applied to potatoes for the control of late blight. Blight risk was increased in 2024 due to the wet conditions [8]. Folpet was the most used fungicide in terms of both area treated and weight applied. Folpet is a multisite fungicide, and is a valuable tool for managing resistance and extending the life of other fungicide groups such as SDHIs.