Loading...
Hydroponic cultivation of Tetragonia decumbens in seawater dilutions for commercial agriculture
Author(s)
Ntoyaphi, Lufefe
Date Issued
2024
Type
Thesis
Publisher
Cape Peninsula University of Technology
Abstract
The production of agricultural products is severely impacted by climate change, rising soil
salinity, and developing freshwater shortages in many different nations, most notably South
Africa. Soil salinization is a serious environmental threat to agricultural productivity and food
security around the world. It impairs the structure of the soil, the availability of nutrients, and
the growth of plants, resulting in lower agricultural yields. Freshwater shortages also represent
a few of the agricultural factors impacting the production of agriculture and the availability of
food in South Africa. It has been noted that water needs have been rising since the 1950s, yet
the availability of freshwater has been steadily declining. In water-constrained regions, the
development of agricultural irrigation competes with rising household and industrial
requirements, which could result in excess water being transferred to high-priority sectors at
the expense of agriculture. As food production and a lack of water develop, these complex
changing factors put strain on agriculture in many areas where traditional water sources are
used for irrigation. Therefore, investigation on dune spinach propagation, salinity stress,
cultivation, and nutritional values is required.
The aim of this research is to examine the impact of diluted seawater and different pruning
intervals on the nutritional profile, antioxidant capacity, and vegetative development of T.
decumbens shoots grown hydroponically. Tetragonia decumbens cuttings were collected from
a specific clone plant that was flourishing alongside the coastline at Granger Bay, Western
Cape. A stem cutting propagation technique was used to root new plant material. Four
identically designed Nutrient Film Technique (NFT) structures configured in a full block design
were set up, with different diluted seawater concentrations (100% tap water/50L, 20%
seawater/50L, and 40% seawater/50L) in each sump. Nutrifeed was essential for proper
nutrition across all systems. Dune spinach plants grown within these circumstances had four
different pruning intervals (unpruned, 15 cm, 30 cm, and 45 cm cuts). The plant growth was
measured with a tape measure, and the pruned fresh and dry plant components were weighed
on a laboratory scale. The data obtained from shoot samples subjected to diluted seawater
and different pruning intervals was statistically computed using a two-way examination of
variance (ANOVA). The Fisher’s least significant difference will be used to compare the
significant differences between treatment means at p≤0.05 using MINI-TAB statistical
software. The amount of chlorophyll in dune spinach plants was determined using a Konic Minolta meter (SPAD-502). Dune spinach shoots were dried and tested for total flavonols,
total polyphenols, ABTS, ferric reducing antioxidant power (FRAP), and DPPH to determine
phytochemicals and antioxidants. The dried T. decumbens shoots were evaluated by using
tests for crude proteins, crude fat content, ash content, moisture content, Neutral Detergent
Fibre (NDF) and Acid Detergent Fibre (ADF), macro-elements (sodium, phosphorus, magnesium, potassium, calcium, K/Ca+Mg, nitrogen), and micro nutrients (magnesium, zinc,
copper and iron) to determine its nutritional values.
Plants cultivated in 20%SW with pruning intervals of 30 and 45 cm produced large quantities
of both dry and fresh weights of dune spinach shoots at weeks 4 and 12, but at week 8 they
started to decline. Increased polyphenol, flavonol, and FRAP capacity were observed in
diluted seawater (20%SW) at pruning intervals of 15 and 30 cm. In contrast, the control shown
enhances both DPPH and ABTS capacity. Macronutrients (magnesium, salt, and nitrogen),
micronutrients (copper and zinc), and proximate components (ash, moisture, and crude
protein) produced significant yields in plants cultivated in 20%SW with three different pruning
intervals (15 cm, 30 cm, and 45 cm).
salinity, and developing freshwater shortages in many different nations, most notably South
Africa. Soil salinization is a serious environmental threat to agricultural productivity and food
security around the world. It impairs the structure of the soil, the availability of nutrients, and
the growth of plants, resulting in lower agricultural yields. Freshwater shortages also represent
a few of the agricultural factors impacting the production of agriculture and the availability of
food in South Africa. It has been noted that water needs have been rising since the 1950s, yet
the availability of freshwater has been steadily declining. In water-constrained regions, the
development of agricultural irrigation competes with rising household and industrial
requirements, which could result in excess water being transferred to high-priority sectors at
the expense of agriculture. As food production and a lack of water develop, these complex
changing factors put strain on agriculture in many areas where traditional water sources are
used for irrigation. Therefore, investigation on dune spinach propagation, salinity stress,
cultivation, and nutritional values is required.
The aim of this research is to examine the impact of diluted seawater and different pruning
intervals on the nutritional profile, antioxidant capacity, and vegetative development of T.
decumbens shoots grown hydroponically. Tetragonia decumbens cuttings were collected from
a specific clone plant that was flourishing alongside the coastline at Granger Bay, Western
Cape. A stem cutting propagation technique was used to root new plant material. Four
identically designed Nutrient Film Technique (NFT) structures configured in a full block design
were set up, with different diluted seawater concentrations (100% tap water/50L, 20%
seawater/50L, and 40% seawater/50L) in each sump. Nutrifeed was essential for proper
nutrition across all systems. Dune spinach plants grown within these circumstances had four
different pruning intervals (unpruned, 15 cm, 30 cm, and 45 cm cuts). The plant growth was
measured with a tape measure, and the pruned fresh and dry plant components were weighed
on a laboratory scale. The data obtained from shoot samples subjected to diluted seawater
and different pruning intervals was statistically computed using a two-way examination of
variance (ANOVA). The Fisher’s least significant difference will be used to compare the
significant differences between treatment means at p≤0.05 using MINI-TAB statistical
software. The amount of chlorophyll in dune spinach plants was determined using a Konic Minolta meter (SPAD-502). Dune spinach shoots were dried and tested for total flavonols,
total polyphenols, ABTS, ferric reducing antioxidant power (FRAP), and DPPH to determine
phytochemicals and antioxidants. The dried T. decumbens shoots were evaluated by using
tests for crude proteins, crude fat content, ash content, moisture content, Neutral Detergent
Fibre (NDF) and Acid Detergent Fibre (ADF), macro-elements (sodium, phosphorus, magnesium, potassium, calcium, K/Ca+Mg, nitrogen), and micro nutrients (magnesium, zinc,
copper and iron) to determine its nutritional values.
Plants cultivated in 20%SW with pruning intervals of 30 and 45 cm produced large quantities
of both dry and fresh weights of dune spinach shoots at weeks 4 and 12, but at week 8 they
started to decline. Increased polyphenol, flavonol, and FRAP capacity were observed in
diluted seawater (20%SW) at pruning intervals of 15 and 30 cm. In contrast, the control shown
enhances both DPPH and ABTS capacity. Macronutrients (magnesium, salt, and nitrogen),
micronutrients (copper and zinc), and proximate components (ash, moisture, and crude
protein) produced significant yields in plants cultivated in 20%SW with three different pruning
intervals (15 cm, 30 cm, and 45 cm).
Additional information
Thesis (Master of Horticultural Science)--Cape Peninsula University of Technology, 2024
File(s)![Thumbnail Image]()
Loading...
Name
Ntoyaphi_Lufefe_217128424.pdf
Size
2.56 MB
Format
Adobe PDF
Checksum
(MD5):c4ac9b056b12a02ba1e5439742e66dd5