ABSTRACT
Straw burning destroys some wildlife which would benefit if burning was restricted by law. Burning also reduces weed and cereal regrowth populations and in its absence their control may require additional herbicide treatment, for example with paraquat, which kills plants quickly and is toxic to aphids, thus preventing the spread of Barley Yellow Dwarf Virus. Slugs are favoured by straw either on the surface or incorporated into the soil and recently there has been a large increase in the use of molluscicides, especially methiocarb. The influence of three methods of straw disposal were studied in relation to two drilling techniques and to the use of methiocarb. More aphids and more virus was found in direct drilled winter wheat following methiocarb treatment. In winter barley more virus was found on ploughed than on direct drilled plots. It is suggested that these effects result from the impact of treatments on the natural enemies of aphids. The implications of using broad-spectrum pesticides in relation to straw disposal are discussed.
