Seed should always be tested for germination, pests and diseases. Growers are advised to request the germination level on certified seed and have homesaved seed tested by a reputable laboratory, so that the results can be used – together
with seed size or TGW – for calculating sowing rate.
Modern UK varieties have good Ascochyta resistance, but seed with over 1% infection should not be used. In addition, seed shown to have any infection of stem nematode should not be drilled.
Imported varieties must have their health status checked, as neither Ascochyta nor stem nematode are likely to be tested for in France or any other bean-producing country.
Plant Population/Seed Rate
Planting density has a large effect on yield. Seed rates should be calculated using the following equation:
TGW x target population x 100
% germination 100 – expected field loss
The aim is to get well-established plants at the 1-2 node stage, or two pairs of leaves, before the winter sets in. While this is normally achieved by sowing mid-October to early November, there is flexibility with sowing date. Modern winter bean varieties can still be sown throughout December and January and into February.