Main Objectives
Main Objectives
In 2020, when the seed treatment was not available, virus levels averaged 38%, at a cost to the industry estimated to be £67M by Defra.
Six different sites are to be selected that meet the following broad requirements:
- Representative of soil type (3 sandy soils, 2 clay soils, and 1 silty soil)
- Differing geographical locations (as much as possible)
- Different climatic conditions (e.g., low/high rainfall areas), if possible
- A full pesticide use history (5 years) of the selected sites should be available
At each site the following sampling regime for soil and field margin vegetation will be followed:
Soils
- 3 sampling occasions: pre-drilling (baseline), within growth season (GS39), and post-harvest (within 1 month or before another crop drilled)
- On each occasion: 15 in-field cores and 15 field-edge cores at 2 depths (0-20 and 20-40 cm)
- At each depth, samples will be bulked to give n=3 samples (5 individual cores per bulk sample)
- A selective bulking strategy will be used for the in-field cores
- Randomised bulking will be used for the field-edge cores
- Samples per occasion: 3 x 0-20 cm in-field bulk samples, 3 x 0-20 cm field-edge bulk samples, 3 x 20-40 cm in-field bulk samples, 3 x 20-40 cm field-edge bulk samples = total 12 samples
- Samples per site = 36 (3 sampling occasions)
- Total samples = 216 (6 sites)
Field margin vegetation
- 2 sampling occasions: majority of plants in flower, and in advance of harvesting (Autumn)
- On each occasion: 3 whole plant samples
- Samples per occasion: total 3 samples
- Samples per site = 6 (2 sampling occasions)
- Total samples = 36 (6 sites)
- Additionally, plant species at each site will be photographed in advance of first sampling occasion
Pollen
- 2 sampling occasions: within sugar beet growth season and just prior to harvest
- On each occasion: Up to 1 kg of flower heads will be obtained from the field margin area
- Samples per occasion: 1
- Samples per site = 2 (2 sampling occasions)
- Total samples = 12 (6 sites)
All samples are sent to the analytical lab (Smithers) for residue analysis of TMX and clothianidin under the appropriate OECD or EPA GLPs.
Outcomes / Key Message For Growers And Industry
Please see reports issued.