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Calobota sericea (Thunb.) Boatwr. & B.-E.van Wyk (Fabaceae) is a native legume from the semi-arid rangelands of South Africa. The species has been prioritised as a forage for water-limited agro-ecological areas. No information regarding the nutritional quality of C. sericea forage harvested at different phenological stages is currently available, limiting our knowledge as to the best time to harvest the forage. The aim of this study was to determine the nutritional quality of C. sericea forage harvested at five phenological stages. Results from the study show that crude protein, fibre, energy and digestibility of the forage decreased with plant maturity, but not all mineral nutrients showed the same trend. In general, C. sericea forage harvested at non-reproductive, early flower bud and full flower stages could provide sufficient energy and protein to maintain livestock condition. At these stages, the neutral detergent fibre and digestibility of the harvested materials are also good, indicating that intake and processing of these forage would not be a problem for the livestock. At these phenological stages most of the mineral nutrients were also sufficiently high to meet the minimum requirements of small stock. Thus, C. sericea forage harvested at the appropriate phenological stages could provide a useful source of forage for resource poor farmers. [ABSTRACT FROM AUTHOR]

This note considers functions of two variables which are continuous on a possibly unbounded closed region in [vertical bar]R[squared], and the functions of one variable obtained by integrating out the other variable over this region. The question of continuity of these functions is investigated, as are connections with joint density and marginal density functions.

Calobota sericea is a native legume of South Africa, confined to the water-limited rangelands, and it has recently been prioritised for additional characterisation regarding its pasture potential. In this study, we examined the growth characteristics of C. sericea under glasshouse conditions where water limitation was implemented at different plant ages, and for different durations. Results indicate that preferential resource allocation to the roots, as well as reduced stomatal conductance and transpiration, were early responses to water limitation, irrespective of the age at which water limitation was imposed, or the duration of water limitation. Under water-limited conditions, increased production of protective pigments, such as carotenoids and anthocyanins, was also observed, which helped in recovery after rewatering. It was concluded that after rewatering, all negative impacts of water limitation on morphology and physiology of C. sericea plants were generally returned to well-watered levels. This suggests that C. sericea plants employ a wide range of phenotypic adjustments in response to water limitation, which makes the plants well adapted to areas with high rainfall variability. [ABSTRACT FROM AUTHOR]

Fabaceae plants contribute greatly to a high quality of pasture in rangelands, because of high levels of protein in their tissues. Despite this established importance, only a few southern African legumes have been evaluated for nutritional value and domestication. The Overberg renosterveld vegetation of the Fynbos biome occupies undulating landscapes that have multiple slope aspects, creating variable microclimatic conditions affecting nutrient dynamics, species richness and plant chemical compositions. We assessed the effect of slope aspect on fiber and mineral composition of forage species present to provide information on the importance of slope for species characterization and nutritional value for domestication. Tissue samples from six replicates of the same species occurring on opposing aspects were collected for nutritional assessment. Results on the data showed that fibre and mineral composition differed in species occurring on different slopes, albeit with few exceptions. The concentrations of P, K and Mg in some species were significantly higher on the cooler and wetter south facing slopes relative to north facing slopes. Nutrient elements in soil samples collected from each site varied with slope aspects and elements. It is recommended that topography should be considered when studying forage nutritional assessments as part of future domestication programs. [ABSTRACT FROM AUTHOR]