Optimum Harvest Date for Barley and Triticale Silage.

Small grain silage should be ensiled between 300 and 350 g kg^-1 dry matter (DM). The objective was to determine the consequences of harvesting in this DM zone to forage yield and quality for barley compared to triticale. Two barley (cv. Falcon and Gadsby) and two triticale (cv. Taza and 94L) cultivars were harvested five times from boot until hard dough stage (DS) at 7-day intervals for barley and 10-day intervals for triticale, when grown at two locations and three planting dates. Data were combined over locations, planting dates and cultivars for triticale, but barley cultivars were handled separately. Regression equations were developed using accumulated growing degrees days greater than zero (GDD) from boot stage to other sequential harvests as the independent variable and yield (DMY), relative DMY (RDMY), DM concentration (PDM), DS, in vitro true digestibility (IVTD) and neutral detergent fiber (NDF) as the dependent variables. Triticale attained 300 g kg^-1 DM at 300 GDD after the boot DS compared to barley at 400 GDD; however the drying rate of triticale was slower than barley. This allowed a comparison of other dependent parameters at 400 GDD post boot DS. RDMY for barley was 92 to 94% compared to 88% for triticale, but Falcon, Gadsby and triticale yields were 11.5, 13.7 and 14.4 Mg ha^-1, respectively.  DS was approximately 85 (soft dough) for barley and 75 (medium milk) for triticale. IVTD decreased from boot, to hard dough DS, but more rapidly for barley than triticale; NDF decreased for triticale, but changed little for barley.  In the harvest zone IVTD and NDF were slightly higher and lower, respectively for barley than triticale. Triticale was drier at any point than barley, but the slower drying rate allowed it to reach a higher DMY if harvested at PDM up to 350 g kg^-1.