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Film antitranspirant application to enhance spring drought tolerance of oilseed rape (Brassica napus L.)

Faralli, M. (2017) Film antitranspirant application to enhance spring drought tolerance of oilseed rape (Brassica napus L.). Doctoral thesis, Harper Adams University.

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Abstract

Oilseed rape (OSR) is an important crop worldwide and drought occurring during reproduction is the main limitation on yield. Following the recent problems in breeding new drought tolerant OSR varieties, there is potential for agronomic exploitation of film antitranspirant (AT) application to avoid yield losses. The main objectives of this study were i) to evaluate whether AT application during OSR r eproductive stages may sustain yield under drought; ii) to elucidate the physiological mechanisms behind the potential AT- induced yield mitigation; iii) to explore the apparent physiological inconsistency between the old and the new work on AT. In four glasshouse experiments and two field experiments drought conditions were applied at different phenological stages and OSR plants were sprayed with different AT chemicals. Three experiments were carried out on OSR seedlings in growth chambers under different atmospheric CO 2 concentration, drought conditions and sprayed or not with AT. The data showed physiological amelioration and yield loss mitigation from application of 1% v/v (glasshouse) and 1 L ha -1 (field) of a commercially -available AT (Vapor Gard) jus t prior to flowering (GS 6.0) on droughted OSR . The AT application under drought triggered complex physiological mechanisms, collectively leading to a sustained photosynthetic rate, reductions in ABA concentration, improved leaf water status and therefore sustaining pod and, to a greater extent, seed production. In addition, the data show that increasing the atmospheric CO 2 concentration does not have an ameliorative effect on OSR seedling’s drought tolerance. On the contrary, the experiments showed that in recent years the increased atmospheric CO 2 concentration may have counteracted the source- limiting effect of AT following increasing substrate available at the site of carboxylation, therefore leading to higher potential efficiency of AT chemicals under w ater -limited conditions. To conclude, AT may deserve further investigation as a potential and flexible management tool to counteract drought damage to OSR yield.

Item Type: Thesis (Doctoral)
Divisions: Crop and Environment Sciences
Depositing User: Ms Kath Osborn
Date Deposited: 23 Aug 2018 14:08
Last Modified: 23 Aug 2018 14:13
URI: http://hau.collections.crest.ac.uk/id/eprint/17324

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