Modern production of chrysanthemum entails the use of supplemental light, which is energy costly. Growers typically produce a large range of chrysanthemum genotypes in the same greenhouse. Also, chrysanthemum goes through three developmental stages during production: the vegetative (7-10 days), flower induction (2 days), and flower development stage (approx. 7-8 weeks). Flower induction and flower development require short-day photoperiods (11 hours), whereas photoperiods in the vegetative stage can extend to approx. 16-20 hours. In the interest of energy use efficiency, breeders and producers of chrysanthemum are in the process of switching lighting from HPS to LED lamps. This switch to LED lamps makes the spectrum controllable, leading to several questions: i) which combination of light colours leads to optimum (most energy use efficient) growth under LED lamps? ii) could different light spectrum optima exist for different genotypes? iii) adding to the previous question, could different light spectrum optima exist for the different developmental stages? Starting at questions i) and ii), you will grow a range of Chrysanthemum cuttings from different cultivars under several well-defined LED light settings, and measure their shoot growth at the end of the vegetative phase (e.g. biomass, leaf area, leaf thickness). Optionally, you will additionally determine a number of factors that may affect growth rate, such as photosynthesis rate and plant architecture.
- Performing climate chamber and/or greenhouse experiments
- Growth analysis
- Data analysis
- Optionally: photosynthetic gas exchange, analysis of plant architecture (e.g. leaf angle distribution, petiole length)
Interested in doing a BSc or MSc thesis at HPP? Please contact the HPP student coordinator Katharina Hanika.