RT Dissertation/Thesis
T1 "Coloring foods" - development of a suitable cultivation and harvesting system for florets of safflower (Carthamus tinctorius L.)
A1 Steberl,Kathrin
WP 2021/05/05
AB ‘Natural colorants’ usually refer to pigments that are obtained from renewable raw materials such as plants. After the invention of the first synthetic dye in the 19th century, the demand for natural colorants decreased. Studies in recent years, which for example, report on the environmentally harmful and toxic effects of artificial colorants, have led, among other things, to a ban on some synthetic colorants in the EU and to a steady increase in demand for natural colorants again.  
Safflower (Carthamus tinctorius L.) is known as a colorant-providing plant because of the red (carthamin) and yellow colorants (carthamidin) contained in the florets. Carthamidin is an interesting colorant for the food industry due to its water-soluble properties. Due to the increasing demand for ‘Coloring Foods’, the already existing cultivation area of safflower, which is mainly in Turkey, India or China, will not be sufficient in the future. 
There are many open questions regarding the possible cultivation of safflower in Germany or Europe. So far, there are no recommendations for the cultivation and harvesting of safflower to obtain the florets. The manual harvesting practiced in the previous cultivation areas is not an economically viable option in Europe. For the production of safflower florets there are also many uncertainties regarding the potential yield. The given challenges for the cultivation of safflower as a food colorant were dealt with in the present dissertation and resulted in the following objectives:
•	to examine the effect of different cultivars, row spacing, sowing densities and harvest dates on yield parameters for safflower floret production under European conditions,
•	to investigate a mechanical harvest with a combine harvester with regard to quality parameters, threshing and carthamidin yield, 
•	to evaluate and modify the DSSAT CROPGRO safflower model to simulate floret yield under European conditions. 
For this purpose, field trials were conducted in 2017 and 2018. Based on these experiments, three scientific publications have been produced, which form the main part of this dissertation. Publication I investigated different cultivation parameters, such as two different cultivars, row spacing and sowing densities and their effect on the number of branches, capitula, floret yield, carthamidin content and yield at five different harvest dates. In this respect, it was shown that a lower sowing density of 40 plants m-² produced a higher number of branches, capitula and higher yields of florets and carthamidin. The Chinese cultivar achieved the highest carthamidin yields on the third harvest date in 2018 with 34.14 kg ha^-1. Publication II evaluated the differences of two cultivars, three threshing parameter settings at five harvest dates for their threshing yield, dry matter content, carthamidin content and yield. The highest carthamidin yields (19 kg ha^-1) were achieved on the last two harvest dates with the Chinese cultivar and the threshing parameter setting P3. Publication III focused on the modification of the plant growth model CROPGRO for safflower to simulate seed yield and the integration of a new subroutine to simulate the floret yield of two safflower cultivars in two years. It was shown that key variables, such as specific leaf area simulation, could be improved by modifying the model (RMSE: 0.82–24.14 cm^-2 g^-1 and d-index: 0.73–0.78). By analogy with a variable already integrated into the model (pod harvest index) and the introduction of new variables (PETALX, HIPIN, HIPMX), the floret yield could be simulated for the first time (RMSE: 97.24 kg ha^-1 and d-index: 0.79). Both the modification and the new approach have improved the simulation of growth as well as seed and floret yield.
The cultivation of ‘Coloring Foods’ could bring benefits to farmers. In addition to the expansion of crop rotation, the biodiversity and the currently much discussed image of agriculture could be improved. On the one hand, the present dissertation could show that the cultivation of safflower is possible in Germany or Europe. Furthermore, a suitable cultivation and harvesting system could be determined. This could help to reduce the current limitations for the production of florets in Germany and Europe, not only for safflower but also for other ‘Coloring Foods’. As a result, cultivation could be made more attractive and more economical in order to be able to meet the increasing demand in the future on a regional basis.
K1 Saflor
K1 Carthamidin
K1 Färbende Lebensmittel
K1 Blütenfädenernte
PP Hohenheim
PB Kommunikations-, Informations- und Medienzentrum der Universität Hohenheim
UL http://opus.uni-hohenheim.de/volltexte/2021/1873