Emphysiology of the endophyte (Acremonium coenophialum Mor· gao-Jones and Gams)-tall fescue (Festuca arundinllcea Schreb.) as· soci~1tion needs to be understood in order to promote environmental fitness traits of the association while reducing its deleterious effects on ruminants. Our objective was to determine the influence of en· dophyte on drought stress tolerance, persistence, and yield components of field-grown tall fescue on a Typic Hapludalfs soil. A water supply gradient was established during 1988 and 1989 with line-source irrigation on established populations ofO and 80o/o endophyte-infected tall fescue. Whole plots consisted of endophyte infection status, across whi<:h a gradient of water was applied in a strip-split fashion with eight replicates. Tiller population density and herbage yield were determined every 28 d and yield components were measured on selected dates. Relative to populations receiving high irrigation (375...{;50 mm applied), tiller density in nonirrigated stands (0-50 mm applied) from July to October 1988 was reduced an average of 42% in infected tall fescue and 55% in noninfected tall fescue. Tiller density of nonirri· gated, infected populations recovered fully to that of high irrigation treatments by 17 November, whereas that ofnonirrigated, endophyte· free populations recovered to only 62% of irrigated treatments. The advantage in population density due to endophyte infection continued throughout 1989, a relatively wet year. A benefit in total forage yield due to endophyte infection was not consistently evident because of greater yield per tiller in endophyte-free stands in 1989. Enhanced tiller density and survival were associated with endophyte infection during severe water deficit, and this advantage continued throughout the subsequent year. Endophyte infection confers population stability in tall fescue during drought stress through improved tiller and whole plant survival.

Pure stands of 'Grasslands Puna' chicory (Cichorium intybus L.) are productive and responsive to N fertilization in the eastern USA.We conducted a field experiment for 3 yr to investigate productivity and nutritive value of swards including chicory, orchard grass (Dactylis g/omerata L.), and birdsfoot trefoil (Lotus comicu/atus L.) as a func· tion of clipping frequency (3-and 6-wk intervals). Each treatment was replicated three times on an upland site of Dekalb series soil (loamy-skeletal, mixed, subactive, mesic Typic Dystrochrept). Modest rates of N, P, and K were applied annually. Herbage mass, botanical composition, in vitro organic matter disappearance (IVOMD), and crude protein (CP) were determined. Cumulative herbage yield was not influenced by initial sward composition with chicory, chicoryorchardgrass, and chicory-orchardgrass-trefoil averaging 6.8 Mg ha-• during a growing season. Clipping frequency influenced yield with canopies clipped at 6-wk intervals producing 26% more herbage than those clipped at 3-wk intervals. Growth rates of canopies clipped at 6-wk intervals averaged 51 kg ha-• d-1 early in the growing season, suggesting that swards including chicory would be responsive to nutrient inputs and where rapid herbage regrowth and nutrient use by the growing crop are needed. Chicory declined in swards with time, regardless of initial sward composition or clipping frequency. Fluctuations in IVOMD and CP were related to changes in sward composition arising from the interaction of time and clipping frequency. Including orchardgrass and trefoil retarded invasion of less desirable species and so provided a means to control overall sward productivity and herbage composition.

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value of chicory herbage and to identify nutrient inputs that sustain production, especially when high rates of Chicory (Cichorium intybus L.), a highly productive forage under N are applied. Crush and Evans (1990) and Reid et al. midsummer conditions in the eastern USA, often has higher concentrations of minerals relative to grasses and legumes. Low concentra- (1993) reported that the mineral composition of forage tions of minerals in herbage could reduce production efficiency or chicory was comparable to or exceeded that of white create metabolic disorders in livestock. Information on the mineral and red clover (Trifolium repens and T. pratense, respeccomposition of chicory is limited, but it is needed to improve our tively) and perennial ryegrass (Lolium perenne L.). Minunderstanding of nutritive value and inputs required to sustain chicory eral concentrations in chicory met or exceeded recomproduction, especially where high rates of N are applied. We conmended dietary mineral requirements of lactating dairy ducted field experiments for 3 yr on a Ramsey soil (Loamy, siliceous, cows (Jung et al., 1996), and because chicory had a subactive, mesic Lithic Dystrudept) in southern West Virginia to derelatively high B concentration, fertilization with B termine (i) response to increasing fertilizer N and (ii) production of might be warranted. Herbage may contain mineral conchicory as a component of swards, including grass and legume as a centrations that theoretically meet livestock requirefunction of clipping frequency. Mineral concentrations and uptake in available herbage generally increased as N rate increased and were

Chicory (Cichorium intybus L.) is highly productive and responsive to N fertilization under midsummer conditions in the eastern USA. We conducted a field experiment for 3 yr on a Ramsey soil (loamy, siliceous, subactive, mesic Lithic Dystrudept) in southern West Virginia to determine if fertilizer N influenced forage chicory nutritive value and NO3–N concentration. Each N rate (0, 80, 160, 240, or 480 kg N ha−1) was replicated three times in a randomized block design. Swards were clipped at 6‐wk intervals during the growing season. Swards were virtually pure chicory in the first year (1994) regardless of N rate. By the third year (1996), chicory ranged from about 40% (0 N) to less than 5% (480 kg N ha−1) of swards. Botanical composition changes in the sward influenced dry matter (DM) response to N rate and herbage nutritive value. Dry matter production increased with N rate in 1994, but was not affected by N in 1996 when chicory was not a major sward component. More than 70% of total annual DM production in 1994 occurred after the first harvest, but by 1996 was less than 50%, reflecting productivity patterns typical of cool‐season swards. Nitrate concentrations in herbage were greatest (3.5 g kg−1) in 1995, a relatively dry year, and least (2.3 g kg−1) in 1996, when there was less chicory in the sward. Crude protein (CP) and in vitro organic matter disappearance (IVOMD) values indicated high forage quality throughout the course of the experiment.