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Vigour of fungicide-treated and untreated maize seed following storage

Thesis (PhD)--University of Pretoria, 2011.

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Other Authors: Kritzinger, Quenton
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Published: University of Pretoria 2013
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access_status_str Open Access
author2 Kritzinger, Quenton
author_browse Kritzinger, Quenton
author_facet Kritzinger, Quenton
collection Thesis
dc_rights_str_mv © 2008, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria.
description Thesis (PhD)--University of Pretoria, 2011.
format Thesis
id oai:repository.up.ac.za:2263/29542
institution University of Pretoria (South Africa)
last_indexed 2026-06-10T12:39:24.464Z
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provenance_str_mv Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository
publishDate 2013
publishDateRange 2013
publishDateSort 2013
publisher University of Pretoria
publisherStr University of Pretoria
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source_str UPSpace — University of Pretoria Institutional Repository
spelling oai:repository.up.ac.za:2263/29542 Vigour of fungicide-treated and untreated maize seed following storage Kritzinger, Quenton Aveling, Terry A.S. upetd@up.ac.za Govender, Veloshinie Zea mays Ultrastructure Maize Storage Fusarium graminearum Fungicides Germination Emergence Vigour UCTD Thesis (PhD)--University of Pretoria, 2011. An assessment of the effect that conventional storage structures, used by smallscale farmers in northern Kwa-Zulu Natal and southern Mozambique, had on germination and vigour of maize seeds was conducted. The survey confirmed that the methods of storing the seed decreased the quality of the maize seeds. Storing maize in the field was good as a short-term solution as initial germination was 100%. Following storage at suboptimum conditions, germination dropped to 25.3%. Commercially treated maize seeds were compared to the test samples collected. After storage, the commercially treated seeds maintained a germination percentage above 75. Untreated maize seeds were treated with fungicides at the recommended dosages. Thereafter the seeds were subjected to germination and vigour tests according to methods outlined by the International Seed Testing Association. All treatments maintained percentage germination above 75. Apron® XL had the highest percentage germination of 83. This trend was also found following the cold test and greenhouse emergence. None of the treatments differed significantly from the control. In this study none of the treatments caused major imbibition damage as indicated by the percentage weight increase and the low leachate conductivity (1012-1271 ìScm-1g-1). The effect of accelerated ageing (AA, 2 and 4 days) and long-term storage (3 and 6 months) on germination and vigour of treated maize seeds was investigated. In the untreated control and treatments there was a gradual decrease in germination following ageing and storage of the seeds. Apron® XL failed to germinate after 3 months. The decrease in germination was mirrored by the leachate conductivity readings. Thiram was the only treatment to maintain germination after 6 months storage. The seeds were planted in two greenhouse trials to assess the performance of the treatments in vivo. The first trial evaluated the emergence and second the emergence and control of Fusarium graminearum. Results from the first trial showed that following 2 d AA, seeds treated with Thiram had the highest percentage emergence (70.7) followed by Celest® XL (68) and the untreated control (62.7). Following inoculation, a similar trend was seen for the treatments and the untreated control. In relation to the percentage seedlings emerged, the control had the highest percentage diseased seedlings. Celest® XL had the lowest percentage diseased seedlings (10, 2 and 1) but failed to germinate after 6 months storage. Thiram was the only treatment to emerge after 6 months storage. The ultrastructural changes in embryonic roots of the untreated control, Celest® XL and Apron® XL were investigated using transmission electron microscopy. These seeds were subjected to 48 hr rapid imbibition and 2 d AA. The most obvious difference between the untreated control, Apron® XL and Celest® XL was the number and position of the vacuoles. In contrast the lipid layer was still attached to the cell wall in the Apron® XL and Celest® XL treatments but in the untreated control they appeared more concentrated in the cytoplasm. This study proved that Thiram was the best treatment among the fungicides tested. However, these results need to be confirmed using a larger range of maize seed lots. Microbiology and Plant Pathology unrestricted 2013-09-07T15:53:16Z 2008-12-17 2013-09-07T15:53:16Z 2008-09-03 2011-03-16 2008-11-18 Thesis Govender, V 2008, Vigour of fungicide-treated and untreated maize seed following storage, PhD thesis, University of Pretoria, Pretoria, viewed yymmdd < http://hdl.handle.net/2263/29542 > D558/gm http://hdl.handle.net/2263/29542 http://upetd.up.ac.za/thesis/available/etd-11182008-091756/ © 2008, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. application/pdf application/pdf application/pdf application/pdf application/pdf University of Pretoria
spellingShingle Zea mays
Ultrastructure
Maize
Storage
Fusarium graminearum
Fungicides
Germination
Emergence
Vigour
UCTD
Vigour of fungicide-treated and untreated maize seed following storage
title Vigour of fungicide-treated and untreated maize seed following storage
title_full Vigour of fungicide-treated and untreated maize seed following storage
title_fullStr Vigour of fungicide-treated and untreated maize seed following storage
title_full_unstemmed Vigour of fungicide-treated and untreated maize seed following storage
title_short Vigour of fungicide-treated and untreated maize seed following storage
title_sort vigour of fungicide treated and untreated maize seed following storage
topic Zea mays
Ultrastructure
Maize
Storage
Fusarium graminearum
Fungicides
Germination
Emergence
Vigour
UCTD
url http://hdl.handle.net/2263/29542
http://upetd.up.ac.za/thesis/available/etd-11182008-091756/