Green pepper (Capsicum annuum L.) is gaining popularity and the production and
consumption thereof is increasing worldwide. Semi-arid regions are characterized by variable
and unreliable rainfall which necessitates the use of irrigation for sustainable green pepper
production. In this study two field trials were conducted. Objectives of the first trial were to
quantify the effect of irrigation and plant population on the growth and yield of green pepper
and to optimize its plant population for different water regimes. Four water treatments, full
irrigation (781 mm), 70% of full irrigation (627 mm), 40% of full irrigation (497 mm) and
dryland (303 mm) and five plant populations (17 689, 23 674, 29 526, 34 979 and 41 496
plants ha-1) were used in this trial. A line source sprinkler irrigation system was used for water
application. The trial layout was a split plot design with water applications as main treatments
and plant populations as sub-treatments. All treatment combinations were replicated four
times. The full irrigation and 40% of full irrigation treatment increased marketable yield with
274% and 162%, respectively. The 70% of full irrigation treatment increased marketable yield
with 253%. The marketable yield of all irrigation treatments was significantly higher than that
of the dryland treatment. The full irrigationâs marketable yield was however also significantly
higher than that of 40% of full irrigation treatment. The optimum plant population for all
water treatments, excluding 40% of full irrigation was not reached in this trial because the
yield of plant populations (17 689 to 41 496 plants ha-1) used did not reach a turning point,
but still increased linearly beyond 41 496 plants ha-1.
The objective of the second trial was to quantify the effect irrigation and mulching on yield,
water use and water use efficiency. Four water treatments, full irrigation (547 mm), 66% of
full irrigation (481 mm), 33% of full irrigation (417 mm) and dryland (303 mm) and two
mulching (bare and 9 t ha-1 maize straw) treatments were used. A line source sprinkler
irrigation system was also used for this experiment. The trial layout was a split plot design
with water treatments as main treatments and mulching rates as sub-treatments. All treatment combinations were replicated four times. Results indicated that green pepper responded well
to irrigation. Full irrigation, 66% and 33% of full irrigation treatment produced marketable
yield of 37.54, 29.74 and 20.52 t ha-1, respectively. The marketable yield of irrigation
treatments was significantly different from each other and they were all significantly higher
than that of the dryland treatment which produced a marketable yield of 11.92 t ha-1. As
irrigation proceeded over time, the relationship between water use and leaf area index
strengthened. The fully irrigated treatment produced the highest water use efficiency.
Mulching conserves water by reducing evaporation and mitigates negative effects of water
stress on plant growth and yield under semi-arid conditions. At the end of the season,
cumulative water use efficiency from the mulched treatment was 6 g m-2 mm-1, significantly
higher than that of the bare treatment of 5.3 g m-2 mm-1.
Green pepper is very susceptible to water stress and produces poorly under dryland conditions
and any irrigation is beneficial to its production. However results also indicated that green
pepper has the ability to adapt quite well to high plant populations and has demonstrated its
ability to compete for production resources at such populations. The crop also conforms well
to the favourable plant growth conditions provided by the mulch.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:ufs/oai:etd.uovs.ac.za:etd-10182011-131746 |
| Date | 18 October 2011 |
| Creators | Hatutale, Gervasius |
| Contributors | Prof LD van Rensburg, Dr GM Engelbrecht |
| Publisher | University of the Free State |
| Source Sets | South African National ETD Portal |
| Language | en-uk |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.uovs.ac.za//theses/available/etd-10182011-131746/restricted/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University Free State or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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