The diurnal cycling of sugars in grasses impact strip-graze management plans

Soluble sugar concentrations increase in forage plants during the day and decrease at night. The objective of this study was to quantify the sugar concentrations in the upper and lower parts of the grass canopy at the end of a light and subsequent dark period and relate these changes in animal grazing behavior and production responses. Tall fescue (Festuca arundinacea) grown in controlled-environment chambers was cut after a 15-h light and a subsequent 9-h dark period, and tillers were separated into leaves and stems. Leaves, but not stems, demonstrated diurnal fluctuation in sugars. Leaf sugars concentrations, after 15-h of light, were 1.6 times greater than those in leaves following the 9-h dark period. It is suggested that animal production may benefit from afternoon vs. morning turnout onto fresh pastures because of the extra sugars accumulating in the leaves during the day

Daily carbohydrate accumulation in eight tall fescue cultivars

Eight cultivars of tall fescue (Loliumarundinaceum Schreb., S.J. Darbyshire = Festuca arundinacea Schreb.), Barcel, Kenhy, Kentucky-31, Missouri-96, Mozark, Stargrazer, C-1 (an experimental selection), and HiMag, were sampled at 2-h intervals during daylight on four cutting dates. Cultivars varied in concentrations of carbohydrate fractions but accumulation rates were not different. Daily mean total non-structural carbohydrate (TNC) concentrations for cutting dates in May, July, August and September declined from 239 to 231, 143 and 120 g TNC kg?1 adjusted dry weight (ADW) respectively. Concentrations of fructans were highest in July but sucrose, glucose and starch concentrations were highest in May. Sucrose was the largest contributor proportionately to TNC daily means across accessions in May (0·33), August (0·30) and September (0·38). Glucose composed an equivalent proportion of TNC in the August harvest. Starch concentration was highest in May at 53 g kg?1 ADW and lowest in August at 23 g kg?1 ADW. The TNC concentration increased by 22·4 (May), 16·8 (July), 21·0 (August) and 30·8 g kg?1 ADW (September) from dawn to dusk. Forage samples taken to estimate preference by ruminants or for TNC analyses should be cut and preserved within 1 h to control the diurnal variation of TNC proportionately within 0·05. Tall fescue should generally be cut between noon and sunset for TNC concentrations to be greater than the daily mean

A chemically unlocked binary molecular switch

A highly luminescent and sensitive terbium complex of a ligand comprising of a phthalimide group appended to a DO3A moiety is an active pH sensor that is conditional on its previous pH

The diurnal cycling of sugars in grasses impact strip-graze management plans

Soluble sugar concentrations increase in forage plants during the day and decrease at night. The objective of this study was to quantify the sugar concentrations in the upper and lower parts of the grass canopy at the end of a light and subsequent dark period and relate these changes in animal grazing behavior and production responses. Tall fescue (Festuca arundinacea) grown in controlled-environment chambers was cut after a 15-h light and a subsequent 9-h dark period, and tillers were separated into leaves and stems. Leaves, but not stems, demonstrated diurnal fluctuation in sugars. Leaf sugars concentrations, after 15-h of light, were 1.6 times greater than those in leaves following the 9-h dark period. It is suggested that animal production may benefit from afternoon vs. morning turnout onto fresh pastures because of the extra sugars accumulating in the leaves during the day

Daily carbohydrate accumulation in eight tall fescue cultivars

Eight cultivars of tall fescue (Loliumarundinaceum Schreb., S.J. Darbyshire = Festuca arundinacea Schreb.), Barcel, Kenhy, Kentucky-31, Missouri-96, Mozark, Stargrazer, C-1 (an experimental selection), and HiMag, were sampled at 2-h intervals during daylight on four cutting dates. Cultivars varied in concentrations of carbohydrate fractions but accumulation rates were not different. Daily mean total non-structural carbohydrate (TNC) concentrations for cutting dates in May, July, August and September declined from 239 to 231, 143 and 120 g TNC kg?1 adjusted dry weight (ADW) respectively. Concentrations of fructans were highest in July but sucrose, glucose and starch concentrations were highest in May. Sucrose was the largest contributor proportionately to TNC daily means across accessions in May (0·33), August (0·30) and September (0·38). Glucose composed an equivalent proportion of TNC in the August harvest. Starch concentration was highest in May at 53 g kg?1 ADW and lowest in August at 23 g kg?1 ADW. The TNC concentration increased by 22·4 (May), 16·8 (July), 21·0 (August) and 30·8 g kg?1 ADW (September) from dawn to dusk. Forage samples taken to estimate preference by ruminants or for TNC analyses should be cut and preserved within 1 h to control the diurnal variation of TNC proportionately within 0·05. Tall fescue should generally be cut between noon and sunset for TNC concentrations to be greater than the daily mean

Structure of fructans in roots and leaf tissues of Lolium perenne

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