Evaluation of Seven Forage Grasses at Two Cutting Stages

Abstract

Seven forage grasses, i.e., Tanner (Brachiaria cf. mutica), a bermuda grass selection (Cynodon dactylon var. coursii), glabrous Signal (Brachiaria brizantha), Signal (Brachiaria brizantha), Congo (Brachiaria ruziziensis), Star (Cynodon nlemfuensis var. nlemfuensis) and Pangola (Digitaria decumbens) were cut at a 60-day harvest interval and at the optimum stage for harvest during a 2-year period at the Gurabo Substation. It was considered that plants had reached the optimum stage for harvest when flowering and yellowing of leaves at the basal parts of the plant began to appear and the grasses had attained a reasonable forage volume as compared to adjacent plots harvested every 60 days. At the 60-day harvest interval, the top yielder was the glabrous Signal; this grass produced 72.78, 19.85 and 1.40 tons of total green, dry forage, and crude protein per acre per year, respectively. Signalgrass was second best with 69.93,16.87 and 1.20 tons of green, dry forage and crude protein per acre per year, respectively. At the optimum stage for harvest, the top yielder in terms of total green forage per acre per year was Congograss with 70.40 tons. The best dry forage and crude protein yielder was glabrous Signal with 18.84 and 1.54 tons per acre per year, respectively. Pangolagrass was second best in terms of total green and dry forage per acre per year with 69.90 and 17.30 tons, respectively. The green forage yields of the grasses studied, except Tannergrass, were similar when cut at the 60-day harvest interval as compared to the optimum stage for harvest. The annual dry forage yield also was similar at the two cutting stages, except Tannergrass and C. dactylon var. coursii. Significantly higher protein yields were obtained at the optimum stage for harvest in all forages with the exception of Signalgrass. Glabrous Signal (Brachiaria brizantha), USDA PI 255346, was the top dry forage yielder of the seven grasses studied. This grass produced about 20 tons of dry forage (73 tons of green forage) containing 7.1 percent of protein and about 19 tons of dry forage (69 tons of green forage) containing 8.2 percent of protein, at the 60-day harvest interval and at the optimum stage for harvest, respectively.