|Reeves Iii, James|
|Foy, Charles - ARS, NRI, CLIMATE STRESS|
Submitted to: Eastern Native Grass Symposium
Publication Type: Abstract Only
Publication Acceptance Date: May 1, 2000
Publication Date: July 1, 2000
Citation: REEVES III, J.B., KRIZEK, D.T., FOY, C.D., RITCHIE, J.C. COMPARATIVE BIOMASS, COMPOSITION, AND FORAGE QUALITY OF GREENHOUSE-GROWTH GAMAGRASS PLANTS DIFFERING IN AGE, STAGE OF DEVELOPMENT, AND DROUGHT TOLERANCE. EASTERN NATIVE GRASS SYMPOSIUM. 2000. Technical Abstract: The primary objective of this work was to evaluate the biomass, composition, and forage quality of eastern gamagrass differing in age, stage of development, and drought tolerance. Young plants were established in the greenhouse from seed. Also 2-year old plants selected from field plots for drought tolerance (DT) or drought sensitivity (DS) in Nov 1997 were transplanted into the greenhouse. Six samples of 15 young plants each were cut back to 25 cm at 80, 94, 108, 122, 147, 164, and 185 days from seeding. Three DT and three DS plants each were treated as above with regrowth harvested at 94, 108, and 122 days. The Least Significant Difference test was used to evaluate differences in composition, biomass, and drought tolerance over time. While little variation in NDF with age was found in young plants, DS plants had significantly higher NDF than DT plants regardless of age. Greater variations were found for ADF, lignin, and CP with age for young plants and for ADF, but not for lignin or CP, for the DT and DS plants. Also, DT plants generally had lower lignin content than DS plants regardless of age. Finally, biomass for young plants differed significantly with age, increasing to day 218, then decreasing. Biomass of DS plants was generally greater than DT plants of the same age. These results show that gamagrass displays complex variations in composition and thus forage quality during aging and in selected genotypes differing in drought tolerance. Overall, forage quality was excellent with CP ranging from 15-18%. Plants were also high in fiber with NDF, ADF, and lignin ranging from 77-85%, 38-43%, and 2.9 to 4.7%, respectively.