16th IFOAM Organic World Congress, Modena, Italy, June 16-20, 2008
Archived at http://orgprints.org/11889
Searching for an alternative oil crop for organic farming
systems in temperate climates
Weber, E.A.1, Elfadl, E.2, Reinbrecht, C.3, Graeff, S. 4 & Claupein, W.5
Key words: safflower, accessions, selection, seed yield, oil content
Abstract
Safflower is an oil crop widely grown in semiarid and arid regions whose oil is valuable
because of its high concentration of polyunsaturated fatty acids. The aim of this
contribution is to give an overview of the methods for identifying potential genotypes
suitable for cultivation in temperate climates. From 2002 to 2005 a great many
safflower accessions from a worldwide safflower collection were screened at several
locations in Germany and Switzerland. More than 75 % of the accessions tested failed
under the humid conditions of the first year because they did not set seed. During
2004 and 2005, seed yield per row and oil content from 486 tested accessions varied
between 0 and 428 g and between 0 and 21 %, respectively. Twenty selected
accessions showed seed yields between 1.4 and 2.1 t ha-1 and oil contents ranging
between 21 and 23 %. Although yield potential of given accessions was strongly
dependent upon climatic factors, well adapted safflower accessions for more humid
conditions were identified. For future research there are several agronomic challenges
to be solved for cultivating safflower in organic farming systems, such as increasing oil
content and optimizing weed and disease control.
Introduction
Safflower (Carthamus tinctorius L.), a member of the family of the Asteraceae, is one
of the oldest cultivated crops. It often is grown on a small scale for personal use and
thus remains a minor crop, with world seed production around 800 000 t per year
(Gyulai, 1996). Commercial oil production from safflower seeds has been conducted
for about 50 years, first for the paint industry and now mainly for its edible oil (Li and
Mündel, 1996). Safflower is grown in more than 60 countries, but mainly in India, USA,
Mexico, Ethiopia, Argentina and Australia (Li and Mündel, 1996). Safflower has very
valuable oil for human nutrition, because of high contents of polyunsaturated fatty
acids, especially linoleic acid (Honermeier, 2006). Apart from the use as an edible oil,
safflower is a crop for multiple purposes. Dyes extracted from florets can be used as
natural food colours or to tint natural cosmetics. Florets as well as seeds are used for
cosmetic products and medicinal purposes in traditional Chinese medicine. Seeds are
also used as birdseed (Li and Mündel 1996). Although, safflower can be grown across
a wide range of latitudes (from 60°N to 45°S) and its product has many uses,
cultivation in Germany currently is negligible (Honermeier, 2006). Because of its
1
University of Hohenheim, Institute of Crop Production and Grassland Research, D-70599
Stuttgart, Germany
2
As Above
3
Pflanzenzucht SaKa GbR, Dorfstraße 39, D-17495 Ranzin, Germany
4
As 1
5
As 1
16th IFOAM Organic World Congress, Modena, Italy, June 16-20, 2008
Archived at http://orgprints.org/11889
applicability in the human health sector as well as its usability for natural cosmetics
and natural medical products, safflower seems to be a very favourable crop for
organic plant production in Central Europe. However, there currently is a lack of
knowledge on potential genotypes suitable to be grown under temperate climatic
conditions, as well as on agronomic factors to optimize seed yield and oil content and
to control weeds and pests. The aim of this study was to search for genotypes
adapted to temperate climatic conditions within a great number of accessions from all
over the world. A methodical approach is given on the ideotyping already done and
the prototyping intended for prospective research.
Materials and methods
In 2002, 741 safflower accessions, obtained from different gene banks, breeders and
official institutions from all over the world, were evaluated at the two locations Ihinger
Hof (SW Germany) and Göttingen (Central Germany). The field trials were set up in a
randomized block design with two replicates. Because of the limited number of seeds,
safflower accessions were sown in microplots of one row of 1.2 m length. Row
distance between different accessions was 40 cm. From the tested pool, 65
accessions were selected according to an index summarizing disease resistance,
seed set, seed yield, etc. These selected accessions were cultivated in 2003 at three
locations, Kleinhohenheim, Göttingen and Klettgau (SW Germany), on plots 1.8x3.0
m. In 2004 and 2005, 20 selected accessions were evaluated at four sites in SW
Germany and Switzerland in a lattice design with four replicates. Fifty seeds per m-²
were drilled in rows with a row spacing of 20-40 cm. Crop management in all trials was
done according to organic standards. Weeding was done mechanically at the rosette
stage, and if necessary, manually. No fertilizer was applied. Twenty agromorphological traits were evaluated. Oil content in per cent was estimated using near
infrared reflectance spectroscopy (NIRS). In parallel, 468 accessions from 49
countries across 15 geographical regions were evaluated at the location
Kleinhohenheim across two seasons. In a simple lattice design with two replicates, 25
seeds from each accession were drilled in a 1.2-m-long row with 75 cm inter-row
distance. Statistical analyses were performed with PLABSTAT (Utz, 2002). An
overview of the selection process is given in Fig. 1.
Fig. 1: Methodology of searching for safflower genotypes adapted to temperate
climates (Ideotyping according to Reinbrecht et al. 2005, Elfadl et al. 2008a,b).
16th IFOAM Organic World Congress, Modena, Italy, June 16-20, 2008
Archived at http://orgprints.org/11889
Results and discussion
Although highly significant genotypic effects for all evaluated parameters could be
observed in 2002, about 75 % of the tested accessions failed because of high disease
attack and thus no seed set (not shown). Most accessions showing satisfying values
originated from Europe, especially Central Europe. Figure 2 depicts in a simplified way
the broad ranges for seed yield, oil content and sensitivity to head rot infestation of the
468 accessions tested in 2004 and 2005. About 5 % of the evaluated accessions had
a mean oil content ranging between 20-25 %, and about 8 % showed a low sensitivity
to head rot infestation between 10 and 20 %.
Fig. 2: Ranges in seed yield, oil content and head rot infestation of 468 safflower
accessions grown in 2004 and 2005 at Kleinhohenheim (means across years
and locations). Each dot represents one accession. Simplified illustration
according to data of Elfadl et al. (2008a).
Figure 3 shows the average ranges in seed yield, oil content and head rot infestation
of the 20 selected accessions evaluated across two growing seasons (2004 and 2005)
and four locations. Thirteen of the 20 selected accessions showed average seed
yields ranging from 1.7 to 2.0 t ha-1, with five between 2.0 and 2.2 t ha-1. Oil content
showed a lower variability, ranging between 21 and 23 %. Head rot infestation ranged
between 13 and 28 %. Although the evaluated parameters depended on climatic
factors, well-adapted safflower accessions could be identified for more humid
conditions that showed satisfactory yield and oil content and low susceptibility to head
rot disease. Since cultivation of the two main oil crops in Central Europe, oilseed rape
and sunflower, entails several problems under organic farming conditions, such as
strong attack by insects, the high demand for nitrogen, and the high susceptibility to
fungal diseases, safflower is considered to be a valuable alternative oil crop for
organic farming systems under temperate climate conditions.
16th IFOAM Organic World Congress, Modena, Italy, June 16-20, 2008
Archived at http://orgprints.org/11889
Fig. 3: Ranges in seed yield, oil content and head rot infestation of 20 selected
safflower accessions tested in 2004 and 2005 at four locations (means across
years and locations). Each dot represents one accession. Simplified illustration
according to data of Elfadl et al. (2008b).
Conclusions
The studies showed that although weather during the particular growing year had an
evident impact on seed yield and oil content, safflower genotypes suitable for organic
farming systems in temperate climates could be identified. However, there are still
agronomic challenges to be solved, such as weed and disease control, to ensure a
successful implementation in organic cropping systems. Additionally, breeding should
be encouraged to increase the oil content of safflower to make it competitive with
other oilseed crops.
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