Abstract
With the advent of new selective post-emergence grass killers for broad-leaf arable crops, basic changes in cropping practices are likely to occur. Complete ‘post-em’ weed-control programmes could both accelerate the trend towards close-row and broadcast seeding of, for example, soya, and stimulate the use of reduced-cost band-spraying in established wide-row crops. By selectively controlling problem grasses they should encourage the adoption of reduced or zero-tillage systems.