An investigation of vascular discolouration in potato tubers (Solanum tuberosum L.) treated with imazethapyr

Spackman, V.M.T., 1998. An investigation of vascular discolouration in potato tubers (Solanum tuberosum L.) treated with imazethapyr. PhD, Nottingham Trent University.

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Abstract

This thesis describes work undertaken to determine the effect of imazethapyr on the morphology and physiology of stored potato tubers. Imazethapyr is an effective sprout suppressant, providing control at least equivalent to industry standards, and the molecule has a very favourable toxicological profile. However, some treated and stored tubers have displayed increased incidence of vascular discolouration. This work identifies links between imazethapyr treatment and vascular discolouration and the conditions under which it may occur.

Imazethapyr treatment was found to cause an increase in tuber respiration, increases in polyphenol oxidase activity, inhibition of mitotic division, disruption of amyloplast integrity and electrolyte leakage. These effects were also examined when imazethapyr was applied to tubers in adverse conditions. In many cases synergistic relationships were detected when imazethapyr was applied at low temperature, acidic pH, with an ethylene-releaser and with immersion in water. In some cases the formulation of imazethapyr could be contributing to vascular discolouration more than the active ingredient itself.

A novel method was developed to trace 14C-imazethapyr through the treated tuber. This study has illustrated the rapid movement of imazethapyr in the tuber periderm and has demonstrated that only a small percentage of applied imazethapyr enters the tuber cortex. The activity detected in the tuber cortex increased when imazethapyr was applied in acidic conditions, suggesting that the increases in vascular discolouration could be due to increased penetration of imazethapyr into the cortex under stress conditions. It is concluded that imazethapyr, in the present formulation, can cause increased incidence of vascular discolouration, particularly when applied under adverse conditions.

Item Type:	Thesis
Creators:	Spackman, V.M.T.
Date:	1998
ISBN:	9781369323450
Identifiers:	Number Type PQ10290096 Other
Rights:	This copy of the thesis has been supplied on condition that anyone who consults it is understood to recognise that its copyright rests with its author and that no quotation from the thesis and no information derived from it may be published without the author’s prior written consent.
Divisions:	Schools > School of Science and Technology
Record created by:	Linda Sullivan
Date Added:	02 Oct 2020 08:36
Last Modified:	28 Sep 2023 10:04
URI:	https://irep.ntu.ac.uk/id/eprint/41094

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