Plant morphology and forage nutritive value of three bahiagrasses as affected by harvest frequency

Differences in morphological development have been reported among bahiagrass (Paspalum notatum Flügge) cultivars. Relationships of harvest management to these developmental differences and subsequent forage production and nutritive value have not been characterized. A 2-yr study was initiated by harvesting 'Argentine', 'Pensacola', and 'Tifton 9′ bahiagrass every 20, 30, or 40 d from mid-May until mid-September. Objectives were to determine if differences exist among these cultivars for leafiness, morphological development, forage mass, and forage nutritive value, and to determine if differences were affected by harvest frequency and season of growth. Leaf percentage by weight, inflorescence development, forage nutritive value, and forage mass were evaluated for monocultures of the three cultivars. Argentine had a greater (P = 0.01) percent leaf (87.2%) than did Pensacola (80.4%) or Tifton 9 (81.0%). In addition, Argentine and Tifton 9 produced fewer (P = 0.01) inflorescences at 20- and 30-d harvest frequencies than did Pensacola. Leaf percentage was greater (P = 0.01) at 20- (88.7%) than at 30- (78.6%) and 40-d (81.4%) harvest frequencies. There were cultivar x plant part interactions (P < 0,05) for neutral detergent fiber (NDF) and lignin, but differences were detected only in the stem component. No differences (P ≤ 0.05) were detected among cultivars for other nutritive value variables. Total forage mass was similar (P ≤ 0.05) among cultivars. Differences in forage mass were detected (P = 0.01) only at the first harvest, where Argentine produced less forage (1.9 Mg ha^-1) than Pensacola (3.1 Mg ha^-1) or Tifton 9 (2.9 Mg ha^-1). The combination of greater leaf percentage and fewer inflorescences indicate that Argentine could have potential advantages as a forage over other bahiagrass cultivars.