Publication Date

1985

Location

Kyoto Japan

Description

Several morphological characters have been associated with yield of forage grasses. Our objective was to evaluate field performance of four generations of tall fescue (Festuca arundinacea Schreb.) that had been selected for differences in leaf area expansion rate (LAE). Yield of reproductive growth at two locations was influenced very little by selection for high LAE, despite a reduction in density of both reproductive and vegetative tillers. Conversely, selection for high LAE led to an increased yield of vegetative regrowth due to higher leaf elongation rate (LER) and higher weight/tiller (WIT) for vegetative tillers that more than offset a decreased tiller density (TD). Selection for low LAE gave the opposite responses. The LER was increased by 0.30 mm and decreased by 0.53 mm per generation, respectively, in the high and low directions of selection. Net photosynthesis of single leaves was not altered by selection for LAE. In vegetative regrowths WIT was inversely related to TD (r= -0.56), but yield per unit land area was increased by selection for high LAE because WIT increased more per generation than TD decreased. The change in herbage yield of vegetative regrowths averaged 182 kg/ha per generation at Mt. Vernon and 107 kg/ha at Columbia. The LAE populations are now being evaluated for agronomic and animal perform(lnce characters.

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Field Performance of Tall fescue Selected for Leaf-Area Expansion Rate

Kyoto Japan

Several morphological characters have been associated with yield of forage grasses. Our objective was to evaluate field performance of four generations of tall fescue (Festuca arundinacea Schreb.) that had been selected for differences in leaf area expansion rate (LAE). Yield of reproductive growth at two locations was influenced very little by selection for high LAE, despite a reduction in density of both reproductive and vegetative tillers. Conversely, selection for high LAE led to an increased yield of vegetative regrowth due to higher leaf elongation rate (LER) and higher weight/tiller (WIT) for vegetative tillers that more than offset a decreased tiller density (TD). Selection for low LAE gave the opposite responses. The LER was increased by 0.30 mm and decreased by 0.53 mm per generation, respectively, in the high and low directions of selection. Net photosynthesis of single leaves was not altered by selection for LAE. In vegetative regrowths WIT was inversely related to TD (r= -0.56), but yield per unit land area was increased by selection for high LAE because WIT increased more per generation than TD decreased. The change in herbage yield of vegetative regrowths averaged 182 kg/ha per generation at Mt. Vernon and 107 kg/ha at Columbia. The LAE populations are now being evaluated for agronomic and animal perform(lnce characters.