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Publication - Report

Scottish winter oilseed rape cultivation 2015-2016: impact of the second year of neonicotinoid seed treatment restrictions

Published: 22 Feb 2017
Part of:
Farming and rural
ISBN:
9781786527981

Survey on the impact of current EU neonicotinoid seed treatment restrictions on Scottish winter oilseed rape cultivation.

55 page PDF

1.5MB

55 page PDF

1.5MB

Contents
Scottish winter oilseed rape cultivation 2015-2016: impact of the second year of neonicotinoid seed treatment restrictions
Appendix 1 - Results tables

55 page PDF

1.5MB

Appendix 1 - Results tables

Table 1 Distribution of census and survey areas of winter oilseed rape in Scotland in 2015/16

Region Census Area (ha) Number of growers surveyed Number of holdings surveyed (1) Surveyed Area (ha) Percentage of census area surveyed
Highlands & Islands 3 0 0 0 0
Caithness & Orkney 0 0 0 0 N/A
Moray 2,493 6 7 319 13
Aberdeen 6,952 25 31 1,559 22
Angus 6,603 28 34 1,204 18
East Fife 1,989 9 11 437 22
Lothian 4,143 14 18 803 19
Central Lowlands 1,388 6 7 226 16
Tweed Valley 6,260 16 23 1,004 16
Southern Uplands 207 0 0 0 0
Solway 103 0 0 0 0
Total Scotland 30,141 104 131 5 , 553 18

(1) Some growers cultivated WOSR on more than one holding

N/A = not applicable

Table 2 Drilling date of winter oilseed rape crops in autumn 2015

Drilling Period Number of growers Percentage of growers Crop area (ha) Percentage of sample area
First two weeks of August 2 2 170 3
Last two weeks of August 84 81 4,472 81
End August/early September 8 8 491 9
September 9 9 359 6
Not specified 1 1 60 1

Table 3 Operational changes in crop cultivation in autumn 2015

Operational Change Number of growers Percentage of growers Crop area (ha) Percentage of sample area
Soil cultivation (1) 6 6 350 6
Drilling date 4 4 203 4
Seed rate/spacing 4 4 221 4
Targeted fertiliser use (2) 2 2 74 1
Any operational change 16 15 847 15

(1) Includes alterations to seed bed production and soil cultivation such as minimum tillage, strip tillage and direct drilling

(2) Includes use of fertilising seed treatment and targeted fertiliser at drilling

Table 4 Methods of pest population assessment conducted in autumn 2015

  Agronomist advice Crop walking Published Information (1) Thresholds Traps
No. growers 89 62 36 29 1
Percentage of growers 86 60 35 28 1

(1) Includes SRUC, AHDB and Bayer technical bulletins (used by 24, 21 and 1 per cent respectively) and farming press (used by 10 per cent)

Table 5 Insect pest pressure in autumn 2015

Pest pressure ranking Aphids Flea beetles
Number of growers Percentage of growers Number of growers Percentage of growers
low (none seen) 14 13 21 20
low 76 73 64 62
low/moderate 1 1 3 3
moderate 5 5 11 11
Moderate/high 0 0 1 1
high 1 1 1 1
Unknown 7 7 3 3

Table 6 Flea beetle species encountered in autumn 2015

  CSFB (2) CSFB & Phyllotreta spp. Phyllotreta spp. (3) unknown
No. growers (1) 13 1 1 6
Percentage of growers 62 5 5 29

(1) Twenty one growers encountered and attempted to identify the flea beetle species present

(2) Cabbage stem flea beetle

(3) Phyllotreta spp. flea beetles

Table 7 Insecticidal sprays applied in autumn 2015

Number of sprays (1) Number of growers Percentage of growers Basic area (ha) (2) Percentage of sample area Total treated Area (3)
None 58 56 3,090 (5) 56 N/A
<1 (4) 5 5 N/A (5) N/A N/A (5)
One 32 31 1,844 (5) 33 1,844 (5)
Two 8 8 601 11 1,202
Three 1 1 18 <1 54
Total 104   5,553   3,100

(1) The total number of sprays applied by growers was 56 (32 x one spray, eight x two sprays, one x three sprays and five part sprays (4))

(2) Basic area is the area of crop treated with an insecticide irrespective of the number of times that area is treated. The total basic area treated with an insecticide was 2,463 ha

(3) Total treated area is the basic area of a crop treated with an insecticide multiplied by the number of treatments that were applied. For example if a field of five hectares gets sprayed with the same insecticide twice, the basic area treated is five hectares, and the total treated area is 10 hectares

(4) These growers sprayed part, but not all, of their crop area with a single spray, therefore the total number of sprays applied by these growers is less than one. These five growers treated 33, 53, 64, 77 and 83 per cent of their crop areas

(5) Crop area for part sprays has been assigned to the appropriate spray categories ( i.e. the area which was not sprayed is assigned to the none category and the sprayed area assigned to the one category)

N/A = not applicable

Table 8 Reasons for insecticide application in autumn 2015

  All growers (n=104) Growers who sprayed (n=46) Growers who didn't spray (n=58)
  Number Percentage Number Percentage Number Percentage
Agronomist advice 84 81 41 89 43 74
Crop walking 42 40 19 41 23 40
Thresholds 18 17 9 20 9 16
Precautionary spray 9 9 9 20 N/A N/A
Technical Bulletins (1) 2 2 2 4 0 N/A

(1) Includes SRUC and AHDB technical bulletins

N/A = not applicable

Table 9 Target of insecticide sprays in autumn 2015

Target pest(s) (1) Number of sprays Basic area (3) Total treated area (4)
Number (2) % of total sprays ha % of sample area ha % of total treated area
CSFB 31 54 1,542 28 1,920 62
Flea beetle (unspecified species) 2 4 53 1 53 2
Rape winter stem weevil 13 23 440 8 518 17
CSFB and rape winter stem weevil 1 2 60 1 60 2
Aphids 3 5 79 1 160 5
CSFB and aphids 2 4 141 3 141 5
Unknown 4 7 133 2 233 7
Phyllotreta spp. flea beetles 1 2 16 <1 16 1
Total 57   2,463   3,100  
Total flea beetle (all species) (5)(8) 37 65 1,812 33 2,190 71
Total rape stem weevil (6)(8) 14 25 500 9 578 19
Total aphids ( 7)(8) 5 9 220 4 301 10

(1) Targets of sprays identified by growers, grouped into common targets

(2) The sprays in this column add up to 57, not 56 as in Table 7, due to one grower spraying two different spray regimes (with different targets) on different areas of his crop i.e. the total number of sprays each composite area received was two, but three different spray regimes were applied overall

(3) Basic area is the area of crop treated with an insecticide irrespective of the number of times that area is treated

(4) Treated area is the basic area of a crop treated with an insecticide multiplied by the number of treatments that were applied. For example if a field of five hectares gets sprayed with the same insecticide twice, the basic area is five hectares, and the treated area is 10 hectares

(5) Collating all sprays with at least one species of flea beetle as a target ( CSFB, flea beetle (unspecified species), CSFB & rape winter stem weevil, CSFB & aphids and Phyllotreta)

(6) Collating all sprays with stem weevil as a target (rape winter stem weevil & CSFB and rape winter stem weevil)

(7) Collating all sprays with aphids as a target (Aphids & CSFB and aphids)

(8) Note that as some sprays had more than one target they have been counted more than once in the collated species data. Therefore when collated targets and unknown sprays are added together they exceed 100% of the total sprays

Table 10 Insecticidal active substances applied in autumn 2015

Active substance (1) Number of sprays (2) Basic area (3) Total treated area (5)
No. % of total sprays ha % of sample area (4) ha % of total treated area (6)
All active substances 57   2,463 44 3,100  
Lambda cyhalothrin 31 54 1,495 27 1,700 55
Zeta cypermethrin 17 30 550 10 779 25
Alpha cypermethrin 5 9 203 4 224 7
Cypermethrin 3 5 195 4 377 12
Pymetrozine 1 2 20 <1 20 <1
Total pyrethroids 56 98 2 , 443 44 3 , 080 99
Total non-pyrethroids 1 2 20 <1 20 <1

(1) All products applied contained only one active substance; all of the compounds listed are pyrethroid insecticides with the exception of pymetrozine which is a pyridine insecticide

(2) The total number of sprays is 57, not 56 as in Table 7, due to one grower spraying two different spray regimes (with different active substances) on different areas of his crop i.e. the total number of sprays each composite area received was two, but three different sprays were applied overall

(3) Basic area is the area of crop treated with an insecticide irrespective of the number of times that area is treated

(4) The percentage of sample area is the basic area of each active substance divided by the sample area

(5) Treated area is the basic area of a crop treated with an insecticide multiplied by the number of treatments that were applied. For example if a field of five hectares gets sprayed with the same insecticide twice, the basic area is five hectares, and the treated area is 10 hectares

(6) The percentage of total treated area is the treated area of each active substance divided by the total treated area

Table 11 Efficacy of pest control regime in autumn 2015

  Growers who sprayed (n=46) Growers who didn't spray (n=58)
Number Percentage Number Percentage
High pest numbers made control difficult 3 7 0 0
Weather prevented spraying 2 4 6 10
Insufficient insecticide efficacy 1 2 N/A N/A
Encountered problems 6 13 6 10
Did not encounter problems 40 87 52 90

N/A = not applicable

Table 12 Insect damage in autumn 2015

Number of growers Percentage of growers Crop area (ha) Percentage of sample area
None 16 15 902 16
Low 70 67 3,696 67
Low/moderate 3 3 199 4
Moderate 12 12 594 11
High 1 1 57 1
Unknown 2 2 104 2

Table 13 Insect pests causing crop damage in autumn 2015

Pest Number of growers Percentage of growers Crop area grown (1) (ha) Percentage of sample area
CSFB (2) 63 61 3,649 66
CSFB/rape winter stem weevil (3) 2 2 101 2
Phyllotreta spp. flea beetles (4) 2 2 26 <1
Rape winter stem weevil (5) 1 1 30 1
Unknown insect pest (6) 18 17 740 13
No insect damage reported 16 15 902 16
Insect damage levels unknown 2 2 104 2

(1) It should be noted that this is the total crop area grown by those who reported damage, not necessarily the crop area affected by that pest

(2) For CSFB damage, levels were ranked as low by 79% of these growers, low/moderate or moderate by 19% and high by 2%

(3) For CSFB/rape winter stem weevil, levels were ranked as low by one grower and moderate by the other

(4) For Phyllotreta spp. flea beetle, both growers reported damage to be low

(5) Rape winter stem weevil damage was reported to be low by the single grower who reported this pest

(6) Where the insect pest causing damage was unknown, damage was reported to be low by 94% of growers and moderate by 6%

Table 14 Grower perception of autumn 2015 insect damage in relation to pre-restriction levels

Did the lack of an insecticidal seed treatment result in greater crop damage? Number of growers Percentage of growers Crop area (ha) Percentage of sample area
Yes 40 38 2,638 48
No 56 54 2,615 47
Don't know 8 8 300 5

Table 15 Non-insect pests causing crop damage in autumn 2015

Pest Number of growers Percentage of growers Crop area grown (1) (ha) Percentage of sample area
Slugs (2) 86 83 4,652 84
Pigeons (3) 30 29 1,585 29
Rabbits (4) 2 2 54 1
Geese (5) 1 1 38 1
Deer (6) 1 1 30 1
Non-insect pest damage reported (7) 98 94 5,272 95
No non-insect pest damage reported 5 5 256 5
Unknown 1 1 24 <1

(1) It should be noted that this is the total crop area grown by those who reported damage, not the crop area affected by that pest

(2) For slug damage, levels were ranked as low by 48%, low/moderate or moderate by 33% and moderate/high or high by 20%

(3) For pigeon damage, levels were ranked as low by 30%, moderate by 43%, moderate/high or high by 23% and unknown by 3%

(4) For rabbits, one grower reported damage to be moderate, and one grower as high

(5) Goose damage was reported to be moderate by the single grower who reported this pest

(6) Deer damage level was not reported by the single grower who reported this pest

(7) The total is less than the sum of the pests above as several growers reported more than one pest species

Table 16 WOSR crop loss in autumn 2015

Reason Number of growers Percentage of growers Crop area (ha) Percentage of sample area
Non-insect pests (1) 4 4 39 0.7
Weather related (2) 3 3 59 1.1
Total crop loss 7 7 98 1.8

(1) Slugs (3 growers, 33 ha) and geese (1 grower, 6 ha)

(2) Wet weather and flooding

Table 17 Average WOSR yield in 2016

Region Number of growers Area of crop grown Average 2016 yield (t/ha)
Aberdeen 23 1,460 3.48
Angus 27 1,188 3.47
Central Lowlands 6 226 3.51
East Fife 9 437 3.56
Lothian 14 803 3.09
Moray 5 185 3.00
Tweed 14 871 3.85
Total (1) 98 5,17 0 3.46

(1) 98 of the 104 original survey respondents provided yield data

Table 18 Reasons for change in 2016 yield

Yield Change (1) Reason Number of growers Percentage of growers (2) Crop area (ha) Percentage of area (2)
Decrease (n=82) Weather conditions (3) 54 66 2,731 61
Weather conditions (3) & late drilling 1 1 29 1
Weather conditions (3) & disease (4) 4 5 640 14
Weather conditions (3) & disease (4) & pests (5) 1 1 26 1
Weather conditions (3) & pests (5) 4 5 165 4
Weather conditions (3) & weeds 1 1 20 <1
Weather conditions (3) & late drilling & pests (5) 1 1 30 1
Disease (4) 1 1 69 2
Late drilling 2 2 109 2
Weeds 1 1 58 1
Pests (5) 2 2 36 1
Poor soil 1 1 30 1
Not recorded/unknown 9 11 561 12
Total reporting yield decrease 82   4 , 503  
Increase (n=7) Different variety 2 29 47 20
Better weather conditions 1 14 57 24
Better weather conditions & fewer pests 1 14 28 12
Better cultivation and establishment 1 14 49 21
Not recorded 2 29 51 22
Total reporting yield increase 7   233  

(1) Reasons are only reported where a change in yield (> 5%) was encountered. No change was reported by nine growers, growing 434 ha

(2) Percentage of growers/area is in relation to total growers with a decrease/increase (3) Weather conditions were cited as a reason for yield decrease by 66 growers in total (80% of those whose yield dropped). 35% of growers reported strong winds immediately prior to harvest causing seed shed, 28% cited a lack of sun in late spring/summer, 23% cited wet conditions in autumn/winter and 6% reported that crop growth had been retarded by the cold spring (4) disease (clubroot) was cited as a reason for yield loss by six growers (7%) (5) Pests were reported as a reason for yield loss by 10 growers (12%), six cited slugs, four pigeons and two CSFB


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Email: Pesticide Survey unit