The frequency and transient responses of a CMOS differential amplifier are improved by employing one or more compensating capacitors. The relative position of the application unit can be determined by means for recording the orientation of the application unit controller relative to the reference plane from the association of position with orientation information, such that control instructions, in particular for positional correction may be generated by the application unit controller. Decking boards are securable across the beams. A small storage tank provides a volume of filtered liquid for use in backwashing the filter bed medium. Azelaic acid treatment alone does not induce many of the known defense-related genes but activates a plant’s defense signaling upon pathogen exposure.