Yield Comparison of Four Forage Grasses at Two Cutting Heights and Three Harvest Intervals

Abstract

Four forage grasses, i.e., Pangola, Digitaria decumbens Stent; Tanner, Brachiaria mutica; a Bermuda selection, Cynodon dactylon var. coursii and Hexapangola, Digitaria decumbens Stent, were evaluated under cutting management at the Corozal Substation located in the humid mountainous region of Puerto Rico. The effects of cutting heights of 2 and 6 inches above the ground, and of 30-, 45- and 60-day harvesting intervals were determined over a 2-year period. All grasses received 2 tons of 15-5-10 fertilizer per acre per year. At all cutting heights and harvest intervals, Bermuda (Cynodon dactylon var. coursii) had the highest dry forage yields while Pangola and Hexapangola had the highest crude protein contents. At all harvest intervals the grasses produced more total yields and crude protein per acre yearly when cut to a height of 2 inches than when cut to 6 inches above the ground. Green and dry forage yields produced by the grasses increased and on the average, crude protein content of the grasses decreased with the length of the harvest interval. A significant variety X cutting interval interaction was observed for total dry forage yields. Lower yields were obtained during the dry winter months at all cutting intervals. When cut 2 inches above the ground and every 60 days, Bermuda (Cynodon dactylon var. coursii) produced 28,247 pounds of dry forage per acre yearly containing about 9.0 percent crude protein.