Optimising harvest timing by predicting dry matter content of whole-crop cereals for silage

Abstract

Abstract Timing of harvest is the single most important factor affecting the yield and quality of whole-crop cereals used for conserved feed. Changes in dry matter content (%DM) and relationships to herbage quality and maturation are presented for experiments conducted over three seasons beginning in 2001/ 2002. Changes in crop characteristics such as ear moisture, ear fresh weight, ear dry weight and leaf fraction were monitored to determine whether growers could use crop-based measurements in place of whole-crop % DM content to assist withdecision making close to harvest. A preliminary model defined the rate of crop maturation for a range of currently grown cultivars. Linear patterns of dry down occurred with only small variation in drying rate for the duration of grain filling. A model with specific inputs for cultivar, date of awn tip appearance (GS49), and developmental response to thermal time formed the basis of a decision support tool that enables growers and contractors to predict optimum harvest timing for whole-crop cereals. Keywords: silage maturity, supplements, forage, herbage quality