Forage Yield of Switchgrass (Panicum virgatum) in Pennsylvania1

Abstract The production of forage by a warm‐season grass species (switchgrass, Panicum virgatum L.) was compared with cool‐season grasses in the cool, humid northeastern United States. Dry‐matter yields were obtained from two varieties of tall rescue (Festuca arundinacea Schreb.) and orchardgrass (Dactylis glomerata L.) and three varieties of switchgrass in 1969. Two other varieties of switchgrass failed to become established and another two did not survive the first winter. Plots were harvested at approximately monthly intervals from May 15 to Sept. 15, 1969. Orchardgrass and tall rescue began growing much earlier in the spring, continued to grow later in the fall, and produced 3,200 to 5,000 kg/ha more dry forage over the entire season than switchgrass. During midsummer the switchgrass varieties produced as much or more dry matter than the cool‐season grasses; however, a high value must be placed on the production of forage at this time of year to justify considering switchgrass as a forage species in the cool humid northeastern United States. Yield data were limited to one harvest year (1969) because the switchgrass did not survive the following winter.