A comparison of four mower conditioners on drying rate and leaf loss in alfalfa and grass

Mechanical conditioning of forage can be accomplished by passing the crop t hrough fluted intermeshing rolls or by passing the crop over the tines of a n impeller rotor Three impeller conditioners and one intermeshing roll cond itioner were compared in field experiments. The impeller conditioners diffe red on the type of tine used on the rotor Hood position and impeller speed were the two adjustments made on all impeller conditioners. The linear load on the rolls was the only adjustment made on the intermeshing roll conditi oner The effect of the conditioning mechanisms and their adjustments on dry ing rate and leaf loss in alfalfa and grass crops was measured. Comparisons were made exclusively among impeller conditioners using all adjustment com binations and among all machines with specific aggressive and nonaggressive adjustments selected. In alfalfa, among impeller conditioners exclusively, the fast rotor speed caused about 7.3% leaf loss, which was 1.1 percentage point greater than the leaf loss caused by the slow rotor speed With respe ct to hood position, the maximum average leaf loss was 6.77% and varied by less than 0.1 percentage point. Incidentally: in the first day of drying, a lfalfa conditioned with the fast impeller speed exhibited a 3% greater dryi ng rate constant than the drying rate constant of alfalfa conditioned with the slow impeller speed. In the first day of drying, grass conditioned with the fast impeller speed exhibited a 13% greater drying rate than the dryin g rare of grass conditioned with the slow impeller speed. Iii addition, dry ing rates in alfalfa varies less than 8% and drying rates in grass varied l ess than 10% in the first day of drying with respect to hood position. When comparisons were made exclusively among impeller conditioners, statistical ly significant differences in drying rate and leaf loss were only exhibited between the fast and slow impeller speeds. In the first day of drying, for age (both grass and alfalfa) conditioned by aggressively-set impeller machi nes exhibited drying rates 23 to 63% greater than drying rates of forage co nditioned by the aggressively-set intermeshing roll conditioner: Also in th e first day of drying, forage (both grass and alfalfa) conditioned by nonag gressively-set impeller machines exhibited drying rates 49 to 60% greater t han the drying rates of forage conditioned by the nonaggressively-set inter meshing roll conditioner Results also suggest that aggressively-set impelle r machines, caused 1.7 to 3.4 percentage points more leaf loss than the agg ressively-set intermeshing roll machine, and nonaggressively-set impeller m achines caused 1.2 to 2.2 percentage points more leaf loss than the nonaggr essively-set intermeshing roll machine.