Pesticide usage - soft fruit crops 2018: survey results

General trends

Crop area

The census area of soft fruit crops grown in 2018 was 2,050 hectares (Table 24). This represents a nine per cent increase from 2016⁽³⁾ and an 18 per cent increase from 2014⁽⁴⁾. Since the last survey, the areas of blueberries, mixed/other soft fruits and strawberries have increased (65, 21 and 14 per cent respectively); while the areas of raspberries and blackcurrants have decreased by 17 and eight per cent respectively (Figure 1).

In 2018, strawberries accounted for 56 per cent of the soft fruit area, raspberries 13 per cent, blackcurrants 14 per cent and other soft fruit crops (blueberries, blackberries, gooseberries, redcurrants and other minor crops) 17 per cent (Figure 2).

Figure 1 Census area of soft fruit crops grown in Scotland 2014-2018

Note: areas include both non-protected and protected crops. Multi-cropping is not included

Figure 2 Soft fruit crop areas 2018 (percentage of total area)

Note: areas include multi-cropping

Pesticide usage

The majority of soft fruit crops (93 per cent) received a pesticide treatment in 2018. Strawberries and blackcurrants had the highest overall proportion of crop treated with a pesticide (99 per cent, Table 1). Other soft fruit crops and raspberries were estimated to have lower proportions of treated crop (78 and 77 per cent respectively). In relation to the average number of pesticide applications, the treated area of soft fruit crops received on average 11.2 sprays, compared with 9.3 sprays in the previous survey. Strawberries received the highest number of applications with an average 14.5 sprays. In contrast the all other soft fruit category received the lowest number of sprays, 5.3 on average (Table 1).

It is estimated that the area of soft fruit crops treated with a pesticide formulation in 2018 was ca. 31,800 hectares compared with 26,000 hectares in 2016 and ca. 36,800 hectares in 2014 (Table 23, Figure 3). This represents an increase of 22 per cent since 2016 and a decrease of 14 per cent since 2014.

Figure 3 Area of soft fruit crops treated with the major pesticide groups in Scotland 2014-2018

In terms of weight of pesticide applied, ca. 17.4 tonnes were applied in 2018, compared with ca. 13.2 tonnes in 2016 and ca. 23.7 tonnes in 2014 (Figure 4). This represents an increase of 31 per cent from 2016 and a decrease of 27 per cent from 2014.

Figure 4 Weight of the major pesticide groups applied to soft fruit crops in Scotland 2014-2018

Note: invertebrate biological control agents are applied by number of organisms rather than weight therefore weight data are not presented.

In order to make accurate comparisons between the 2018 data and that reported in previous surveys, it is important to take into account differences in crop areas between 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 2018, for each hectare of crop grown, around 15 treated hectares were recorded (Figure 5). This represents an increase of 10 per cent from 2016 and a decrease of 26 per cent from 2014.

Figure 5 Number of pesticide treated hectares (formulations) per each hectare of crop grown

Note: physical control has been excluded as their use represents <0.1 treated hectares per hectare of crop grown.

The estimated weight of pesticide applied per hectare of crop grown was approximately eight kilograms (Figure 6). This represents an increase of 18 per cent from 2016 and a decrease of 37 per cent from 2014.

The lower pesticide use reported in 2016, mainly driven by lower fungicide use was atypical in this data series. The reduction in overall pesticide use in 2016 was influenced by the cool climatic conditions that year, leading to a lower pest pressure. However, as acknowledged in the 2016 report, it may also have been influenced by a low survey response rate in 2016, which affected sample size and distribution⁽³⁾. Therefore, although pesticide use in 2018 is greater than reported in 2016, overall it is lower than encountered in 2014 and 2012.

Figure 6 Weight of pesticides applied per hectare of crop grown

Note: molluscicides and biopesticides have been excluded as their use represents <0.1 kg per hectare of crop grown.

In 2018, fungicides were the most frequently used pesticides by area treated on soft fruit crops, followed by insecticides/acaricides, biopesticides and herbicides (Figure 7). Fungicides accounted for 53 per cent of the total pesticide treated area and 63 per cent of the total weight of pesticides applied (Figures 7 & 8). When changes in crop area are taken into account, the area treated with fungicide formulations increased by 10 per cent from 2016 to 2018 and decreased by 21 per cent from 2014 to 2018 (Figure 5). From 2016 to 2018, there was an increase of 40 per cent in the weight of fungicides used per hectare of crop grown and a decrease of 29 per cent from 2014 to 2018 (Figure 6).

Sulphur accounted for three per cent of the total treated area and 23 per cent of the total weight of pesticides applied (Figures 7 & 8). When changes in area grown are taken into account, there was a 25 per cent increase in the use of sulphur between 2016 and 2018 and a 52 per cent decrease from 2014 to 2018 (Figure 5). The weight of sulphur applied per hectare of crop grown decreased by one per cent from 2016 to 2018 and by 41 per cent from 2014 to 2018 (Figure 6). When crop area is taken into account, the mean applications of sulphur were 1.9 kg/ha in 2018, 2.0 kg/ha in 2016 and 3.3kg/ha in 2014. The majority of sulphur use encountered in the survey was on blackcurrants.

Figure 7 Use of pesticides on soft fruit crops (percentage of total area treated with formulations) - 2018

Figure 8 Use of pesticides on soft fruit crops (percentage of total weight of pesticides applied) - 2018

Note: invertebrate biological control agents are applied by number of organisms rather than weight therefore weight data are not presented

In 2018, insecticides and acaricides accounted for 19 per cent of the total pesticide treated area and four per cent of the total weight of pesticides applied (Figures 7 & 8). When changes in crop area are taken into account, there is a seven per cent decrease from 2016 to 2018 and a 45 per cent decrease from 2014 to 2018 in the area treated with insecticide/acaricide formulations (Figure 5). In terms of weight of pesticide applied, when area of crop grown is taken into account, there is a 26 per cent increase from 2016 to 2018 and a 62 per cent decrease from 2014 to 2018 (Figure 6). This pattern of decreased treated area, but increased quantity applied from 2016 to 2018 may be explained by the use of fatty acids as an insecticide on protected strawberry crops in 2018. Fatty acids are applied at high rates and accounted for 36 per cent of the total weight of insecticides applied (Tables 2 & 23). No fatty acid use was recorded in 2016. The overall decrease in area treated with insecticides and acaricides may also have been influenced by increased use of alternative methods of insect control such as biological control agents.

Herbicides and desiccants accounted for nine per cent of the total pesticide treated area and seven per cent of the total weight of pesticides applied (Figures 7 & 8). When changes in crop area are taken into account, there is a decrease in area treated with herbicide and desiccant formulations of 34 per cent from 2016 and a decrease of 41 per cent from 2014 (Figure 5). In terms of weight of pesticide applied, when area of crop is taken into account, there is a decrease of 41 per cent from 2016 to 2018 and a decrease of 53 per cent from 2014 to 2018 (Figure 6). Decreases were recorded in key active substances. When corrected for area of crop grown, the glyphosate treated area decreased by 54 per cent from 2016 to 2018 and 16 per cent from 2014 to 2018. The area treated by diquat decreased by 35 per cent from 2016 to 2018 and by 56 per cent from 2014 to 2018. There was substantially less rainfall in winter, spring and summer of 2018 compared to 2016 and 2014, which may have resulted in reduced weed pressure⁽⁵⁾.

In 2018, biopesticides accounted for nine per cent of the total pesticide treated area and one per cent of the total weight of pesticides applied (Figures 7 & 8). When changes in crop area are taken into account, there is an increase of 208 per cent from 2016 to 2018 and an increase of 43 per cent from 2014 to 2018 in the area treated with biopesticide formulations (Figure 5). In terms of weight of pesticide applied, there is an increase of 153 per cent from 2016 to 2018 and an increase of 26 per cent from 2014 to 2018. Biopesticides were recorded on strawberry, raspberry and on other soft fruit crops. The majority of biopesticides were applied to strawberry crops for the control of mildew and botrytis.

Biological control agents accounted for four per cent of the total pesticide treated area. As biological control agents are applied by the number of organisms rather than the weight, no weight data are presented. When changes in crop area are taken into account, there is an increase of 63 per cent from 2016 to 2018 and an increase of 103 per cent from 2014 to 2018 in area treated. Biological control agents were used on strawberry, raspberry and other soft fruit crops. The largest proportion of biological control agent use was recorded on strawberry crops, targeting two-spotted spider mite. This represents a trend towards a significant increase in the use of biopesticides and biological control agents for managing insect pests and disease in soft fruit crops as part of an integrated pest management system.

In 2018, molluscicides accounted for three per cent of the total pesticide treated area and one per cent of the total weight of pesticides applied (Figures 7 & 8). When changes in crop areas between years are taken into account, there is an increase in molluscicide applications per unit area of 152 per cent between 2016 and 2018 and an increase of 72 per cent between 2014 and 2018 (Figure 5). The weight of molluscicides applied per hectare of crop grown increased by 99 per cent from 2016 to 2018 and by 19 per cent from 2014 to 2018 (Figure 6). Molluscicide use varies significantly from year to year as slug populations are closely linked to climatic conditions.

Pesticides classified as physical control agents accounted for less than 0.5 per cent of the total pesticide treated area and one per cent of the total weight of pesticides applied (Figures 7 & 8). Physical control agents are substances that have a physical action against insect pests, for example by blocking insect spiracles and causing death by suffocation. Physical control was recorded on strawberry and raspberry crops and was mainly used for the control of aphids.

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. The use of the fungicide cyflufenamid has increased by 1,249 per cent in terms of area treated since 2016 (Table 21). The use of the biopesticide Bacillus subtilis strain QST 713 has increased by 129 per cent in terms of area treated and is now the second most commonly used active substance on soft fruit by area treated. The use of the fungicides fosetyl-aluminium, potassium hydrogen carbonate and pyrimethanil have increased by 266, 178 and 106 per cent respectively by quantity of active substance applied (Table 22). The fungicides trifloxystrobin, fluopyram, fenpyrazamine and proquinazid, the insecticide cyantraniliprole and the herbicide clethodim were all recorded for the first time on soft fruit crops in 2018 (Table 17).