Nightshade and hairy nightshade are two of the most serious weeds in row crops. Both species build up a persistent seed bank and thus require long-term control strategies. The aim of this project is to evaluate the effects of nightshade in an organic cropping system. In a crop rotation including potatoes, carrots and onions, measures for passively and actively reducing the seed bank will be assessed. As an active measure, use of a mini-fallow (stale seedbed) in July provides unique opportunities to reduce the seed bank. Passive measures such as inter-crops, autumn-sown cereal crops and one-year leys will be used to depress the population of nightshades. Changes in population will be assessed by determining the volume and vitality of the seed bank in each year of the study. This will help identify the control methods which in combination have the greatest effect on the seed bank in the crop rotation, information which can be used in establishing a sustainable weed management strategy.