The susceptibility of hay species to mechanical damage. I. Effects of growing and curing conditions

Abstract

A laboratory method was developed for determining the susceptibi1ity of hay species to mechanical damage and the nature of mechanical losses likely to be encountered during field curing. Three legume species were considered: lucerne (Medicago sativa L.), white clover (Trifolium repens L.), and subterranean clover (T. subterraneurn L.). Twelve of the 17 growing and curing conditions investigated, e.g. maturity, drought, shading, and crushing, significantly affected fragility. Moisture content was particularly important and losses from carrying out field operations at unsuitable moisture contents could outweigh those from all other factors. Many types of damage contributed to the mechanical losses. Breaking up of individual leaflets, and fracture at the leaflet-petiole and petiole-stem junctions, were important but with the clovers the greatest losses resulted from fracture of petioles near the leaf-petiole junctions.