Thesis (MSc. Agriculture (Horticulture)) -- University of Limpopo, 2018 / The production of tomato (Solanum lycopersicum L.) plants had been crucial in various
parts of the world since tomato fruit contribute widely to human health. However, most
tomato cultivars had been shown to be highly susceptible to plant-parasitic nematodes,
especially the root-knot (Meloidogyne species) nematodes. Two cucurbitacin-containing
phytonematicides, namely, Nemarioc-AL and Nemafric-BL phytonematicides,
manufactured from fruits of Cucumis species, are being researched and developed in
South Africa as an alternative for management of Meloidogyne species. Most trials on
tomato plants and cucurbitacin-containing phytonematicides had been under
greenhouse conditions, with limited information on their interactive effects under
microplot and field conditions. The objectives of this study were: (1) to determine the
interactive effects of Nemarioc-AL and Nemafric-BL phytonematicides on growth and
accumulation of nutrient elements in leaf tissues of tomato plants under microplot
conditions and (2) to investigate the interactive effects of Nemarioc-AL and Nemafric-BL
phytonematicides on growth and accumulation of nutrient elements in leaf tissues of
tomato plants under field conditions. In the microplot study, uniform four-week-old
tomato cv. 'HTX 14' seedlings were transplanted in 4 L plastic bags containing loam soil
and Hygromix-T at the 3:1 ratio (v/v). Plastic bags were inserted into holes at 0.50 m
inter-row spacing and 0.60 m intra-row spacing. The 2 x 2 factorial trial, with the first
and second factors being Nemarioc-AL and Nemafric-BL phytonematicides,
respectively, each at two levels. The four treatments, namely, AL0BL0, AL0AL1, BL0BL1
and AL1BL1, were arranged in a randomised complete block design. Treatments were
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applied seven days after transplanting and repeated weekly until harvest. Under field
conditions, uniform four-week-old tomato cv. 'HTX 14' seedlings were transplanted into
the field at 0.50 m inter-row spacing and 0.60 m intra-row spacing. Treatments,
experimental designs and application interval were as those under microplot conditions.
At 60 days after the treatments, seedlings AL × BL interaction was not significant on all
plant variables in Experiment 1 under microplot conditions, whereas in Experiment 2 the
interaction was highly significant (P ≤ 0.01) on dry shoot mass, contributing 72% in total
treatment variation (TTV) of the variable. Relative to untreated control, the two-way
matrix showed that the interaction reduced dry shoot mass by 8%. Nemarioc-AL
phytonematicide had a significant (P ≤ 0.05) effect on stem diameter in Experiment 1
under field conditions, whereas Nemafric-BL phytonematicide had significant effects on
plant height in Experiment 2, contributing 39 and 56% in TTV of the respective
variables. Relative to untreated control, Nemarioc-AL phytonematicide increased stem
diameter by 4%, whereas Nemafric-BL phytonematicide increased plant height by 2%.
The interaction was also significant (P ≤ 0.05) on Na and S and highly significant (P ≤
0.01) on Zn, contributing 76, 26 and 6%, respectively, in TTV of the respective variables
in Experiment 1 under field conditions. Using a two-way matrix, the interaction
increased Na and S by 12 and 41%, respectively, but reduced Zn by 52%. In
Experiment 2, the interaction was highly significant (P ≤ 0.01) on P alone, contributing
16% in TTV of the variable, with the interaction reducing P by 76%. Nemarioc-AL
phytonematicide had significant effects (P ≤ 0.05) on Ca and highly significant effects (P
≤ 0.01) on S, contributing 31 and 58% in TTV of the respective variables in Experiment
1. Relative to untreated control, Nemarioc-AL phytonematicide increased P by 39%. In
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Experiment 2, Nemarioc-AL phytonematicide had significant effects on Ca and highly
significant effects (P ≤ 0.01) on S, contributing 66 and 49% in TTV of the respective
variables. Relative to untreated control, Nemarioc-AL phytonematicide reduced Ca by
19% and S by 36%, respectively. Nemafric-BL phytonematicide had a significant effect
(P ≤ 0.05) on P, contributing 33% in TTV of the variable in Experiment 1. Relative to
untreated control, Nemafric-BL phytonematicide increased P by 41%. In Experiment 2,
Nemafric-BL phytonematicide had significant effects (P ≤ 0.05) on S, contributing 40%
in TTV of the variable. Relative to untreated control, Nemafric-BL phytonematicide
reduced S by 33%. At 74 days after initiating the treatments under field conditions, the
interaction of Nemarioc-AL and Nemafric-BL phytonematicides were not significant for
plant height, stem diameter, fresh fruit and dry shoot mass in both experiments.
Nemarioc-AL phytonematicide was also not significant in all plant variables in both
experiments. Effects of Nemafric-BL phytonematicide were highly significant on dry
shoot mass in Experiment 1 and stem diameter in Experiment 2, contributing 60 and
67% in TTV of the respective variables. Relative to untreated control, Nemafric-BL
phytonematicide reduced dry shoot mass by 28% and increased stem diameter by 11%
in Experiment 1 and Experiment 2, respectively. The AL × BL interaction had significant
effects (P ≤ 0.05) on P, contributing 57% in TTV of the variable in Experiment 1.
Relative to untreated control, the interaction increased P by 12%. In Experiment 2, the
interaction had significant effects (P ≤ 0.05) on K, Mg, S and Mn, contributing 78, 65, 74
and 68% in TTV of the respective variables. Using a two-way matrix, relative to
untreated control, the interaction increased K by 8%, but reduced Mg, Mn and S by 14,
82 and 1%, respectively. Nemarioc-AL phytonematicide was not significant in both the
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experiments, whereas Nemafric-BL phytonematicide had significant effects on Mg in
Experiment 1, contributing 68% in TTV of the variable. Relative to untreated control,
Nemafric-BL phytonematicide increased Mg by 15%. In conclusion, the interaction of
Nemarioc-AL and Nemafric-BL phytonematicides were not compatible with each other
as they had undesirable effects on growth of tomato plants and accumulation of most
essential nutrient elements in leaf tissues of this plant. / National Research Foundation (NRF)
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:ul/oai:ulspace.ul.ac.za:10386/2211 |
| Date | January 2018 |
| Creators | Maake, Mafutha Violet |
| Contributors | Shadung, K. G., Mashela, P. W. |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | xxvi, 99 leaves |
| Relation | Adobe Acrobat Reader |
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