Crop Clinic

Leatherjackets

In grassland, take 25 soil cores each of 2.5” (6.5 cm) diameter along the longest diagonal of the field. Using the special sampling tool, drive each section of pipe into the soil to a depth of about 2.5” (6.5 cm), i.e. up to - but not beyond- the leading edge of the holder on the sampling tool. Retain the soil samples grass uppermost within the pipes for transfer to the laboratory. Avoid long delays between sampling and return of the material to the laboratory - grubs are likely to escape! Where a slight delay is unavoidable, store samples at low temperature, e.g. in a fridge or cold room but never in a deep freeze.

Wireworms

In grassland, take 20 soil cores each 4” (10 cm) diameter and 6-9” (15-23 cm)  deep per field; take 2 cores at random from each one-tenth of the field. Bag and number cores, preferably separately, for transport to the laboratory.

Wheat bulb fly eggs

Use the special shovel provided for sampling the soil in potato crops for wheat bulb fly eggs. The height of the sides is 1.25” (3 cm). Soil samples should be taken approximately to this depth and to the distance of the 3” (7.5 cm) mark scribed on the flat surface of the shovel. Take a total of 24 samples along the longest diagonal of the field, 12 from the furrow and 12 from the ridge. Bag ridge and furrow samples separately. The shovel may also be used to sample the soil in crops other than potatoes (e.g. oilseed rape). In these cases, take 24 samples across the longest diagonal.

Cabbage root fly eggs

Using a dessert spoon, carefully remove the soil from around the stems of 20 randomly chosen, cruciferous plants. Remove soil around each stem to a distance of 1” (2.5 cm) and to the same depth. Deposit samples in a bag for transport to the laboratory.