ABSTRACT
Summary Forms of conditioning treatment are being developed that aim to minimize the barrier effect of the crop cuticle without sacrificing too much of the structural strength of the herbage. Effective surface abrasion and favorable windrow structure can be achieved with steel-spoked rotors, which are now beginning to be offered commercially. More recently, plastic brushes have been developed because the higher population density and yielding ability of the crop-engaging elements, plus the absence of metal components, appeared to offer additional advantages. Four different brush conditioner systems have been evaluated in the laboratory and in replicated field experiments. Tufted brushes using trilobar filaments lifted and conveyed the crops more effectively than full brushes and carried the conditioning effect deeper into the crop layer. With regard to improvement in rate of crop drying and digestible dry-matter yield, levels of effectiveness have been recorded that exceeded those of commercial conditioner systems. Cost of the plastic elements is low. Durability, already near acceptance by farmers, has the potential of being further improved substantially.
