14.11 Cuticle Barriers – Limited Moisture Effects

Plants growing under a limited moisture regime and low relative humidity tend to have a more highly developed cuticle, which is a barrier to absorption of postemergence herbicides (Figure 14). As a result the activity of postemergence herbicides is reduced by dry conditions. Research has shown that the negative effect of dry conditions on postemergence herbicide activity can be offset in part by the use of spray additives.