Primary Supervisor: Professor Peter Kettlewell, Department of Agriculture and Environment
Secondary supervisor: Dr Laura Vickers
PhD project title: Physiology of fruit growth and ripening in strawberry
University of Registration: Harper Adams University
One of the biggest challenges for strawberry growers is managing the peaks (referred to as crop flushes) in the number and size of berries ready for picking. The production pattern of strawberries starts with a few berries ready for picking in the first week, then the number rapidly peaks for a week or two with a flush of berries ready for picking and declines sharply in the final week of fruiting. During a crop flush, berries have to be sold onto a flooded market leading to economic loss from low prices and to post-harvest waste of berries with consequent unnecessary greenhouse gas emissions released in their production. Through better understanding of berry growth and ripening, it may be possible to develop methods to reduce the problem of crop flushes.
Current understanding is that berry growth and sugar accumulation of well-watered plants is dependent on assimilate from photosynthesis, whereas berry ripening is hormonally-determined with ABA having a central role in accelerating ripening in this non-climacteric fruit, rather than ethylene (Jia et al., 2011; Gu et al., 2019).
The aim of this project is to understand the physiology of berry growth and ripening sufficiently to develop new management techniques for reducing crop flushes.
- To review the literature to help define candidate management techniques for potential to reduce crop flushes.
- To understand how the candidate management techniques interact with the physiology of berry growth and ripening.
- To use the understanding from Objective 2 to explore the use of the most promising candidate management techniques to reduce crop flushes.
Year 1 – A literature review will be conducted on non-climacteric fruit growth and ripening and on potential management techniques used in other crops for growth and ripening manipulation e.g. plant growth regulators (Rademacher, 2015) and antitranspirants (Mphande et al., 2020). The review will be used to define candidate management techniques for potential to reduce crop flushes.
Initial experiments will be conducted with strawberries grown in a glasshouse to understand how the most promising candidate management techniques interact with assimilate supply and endogenous hormones to influence berry growth and ripening.
Years 2 and 3 – Based on the literature review and the initial experiments, further experiments will be conducted to test detailed mechanism hypotheses for the action of the most-promising candidate management techniques.
Gu et al. (2019) Transcriptome and hormone analyses provide insights into hormonal regulation in strawberry ripening. Planta 250, 145-162.
Jia et al. (2011) Abscisic acid plays an important role in the regulation of strawberry fruit ripening. Plant Physiology157, 188–199.
Mphande et al. (2020) The role of antitranspirants in drought management of arable crops: A review. Agricultural Water Management 236:106143
Rademacher (2015) Plant Growth Regulators: Background and Uses in Plant Production. Journal of Plant Growth Regulation 34, 845-872.
BBSRC Strategic Research Priority: Sustainable Agriculture and Food:Plant and Crop Science
Techniques that will be undertaken during the project:
- Systematic literature reviewing (with meta-analysis, if appropriate).
- Designing, managing and analysing data from glasshouse experiments.
- Fruit growth and quality measurement
- Plant hormone assays
Contact: Professor Peter Kettlewell, Harper Adams University