Browsing by Author "Cyster, Lilburne"

Now showing 1 - 4 of 4
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    Essential metal and metalloid elements in the Philippi Horticultural area, and their uptake into selected vegetable crops
    (Taylor & Francis, 2018) Malan, Marÿke; Muller, Francuois; Raitt, Lincoln; Cyster, Lilburne; Brendonck, Luc
    This study evaluated Co, Cr, Mn, Ni, Se, Sn and V status in the soils of the PHA, as well as the vegetables produced on these soils. We also determined the agronomic sources of these elements to the soils in the PHA. Farmyard manures applied as fertilizer amendments to the soils in the PHA were found to be the major agronomic sources of the metal and metalloid elements. These elements were however, retained in significantly higher concentrations in the soils compared to the concentrations found in the edible portions of the vegetable crops collected. This, in turn, resulted in these vegetables being poor sources of several of the essential mineral nutrients. It is therefore suggested that: (1) a wider variety of crops are assessed for their mineral nutrient status, (2) to find ways to increase the availability of these mineral nutrients and (3), that the possibilities of micronutrient and trace element deficiencies be assessed in the communities surrounding the PHA.
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    Morphological and physiological responses of Calobota sericea plants subjected to water limitation and subsequent rewatering
    (Taylor and Francis Group, 2021) Müller, Francuois; Raitt, Lincoln; Cyster, Lilburne
    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.
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    Nitrogen fertilization increases the growth and nutritional quality of the forage legume, Calobota sericea – A preliminary investigation
    (Elsevier, 2023) Britz, Ethan; Cyster, Lilburne; Samuels, Igshaan
    Calobota sericea is being evaluated as a forage for drought stressed areas. The nutritional quality of C. sericea from native populations are poor, and this is believed to be due to poor soil fertility. Therefore, a greenhouse trial was established to determine the impact of N-fertilization level (0, 25, 50, 75 and 100 kg/ha) on the growth and nutritional quality of C. sericea plants. Three-monthold plants were harvested and the root and shoot length, as well as branching intensity on each plant determined. Thereafter, the shoots were separated into leaves and stems and all plant parts were oven dried for dry mass determination. After weighing, the leaves and stems for each plant were combined and the dried shoots used for nutrient determination. Results indicated that increased N application levels is positively correlated with improved C. sericea growth. Similarly, mineral nutrient uptake increased significantly under all the N-fertilization treatments and crude protein content increased from 9.6% to 18.6%. Plant growth was only statistically significantly (p < 0.05) improved when N was applied at rates of 50 kg/ha and more, but crude protein content increased from the lowest N application rates (25 kg/ha). The improved growth and nutrient uptake could primarily be explained by improved resource allocation under N-fertilization. Therefore, appropriately fertilized C. sericea can result in improved forage production and improved quality forages and when N is applied at high enough rates.
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    Nitrogen fertilization increases the growth and nutritional quality of the forage legume, calobota sericea – A preliminary investigation
    (Heliyon, 2023) Britz, Ethan; Cyster, Lilburne; Samuels, Igshaan; Clement, Cupido
    Calobota sericea is being evaluated as a forage for drought stressed areas. The nutritional quality of C. sericea from native populations are poor, and this is believed to be due to poor soil fertility. Therefore, a greenhouse trial was established to determine the impact of N-fertilization level (0, 25, 50, 75 and 100 kg/ha) on the growth and nutritional quality of C. sericea plants. Three-month-old plants were harvested and the root and shoot length, as well as branching intensity on each plant determined. Thereafter, the shoots were separated into leaves and stems and all plant parts were oven dried for dry mass determination. After weighing, the leaves and stems for each plant were combined and the dried shoots used for nutrient determination.