Crambe abyssinica

Crambe abyssinica has its origins in eastern Africa and was domesticated in the Mediterranean region. It grows up to a height between , Usually, its straight stalk is moderately branched and its leaves are of an oval shape. The plant's flowers are small and white, arranged in racemes and have four free sepals, four free alternating petals, two shorter and four longer free stamens, what is typical for Brassicaceae. Mostly, these flowers are self-pollinated, but some cases of cross-pollination have been observed. The pericarp of the seed usually adheres to the seed even at harvest. == History of agricultural use and cultivation ==

Crambe has not been in cultivation for a long time. It was probably cultivated for the first time in the 1930s in the former USSR. Later the crop was tested in other regions of the USSR, in Sweden and in Poland, where crambe was grown on 25,000 ha (~62,000 acres) after the second world war. In the 1990s a breeding program was started in the Netherlands. == Cultivation ==

With a germination temperature of which is also equivalent to the basal growing temperature, C. abyssinica is a winter crop in southern Europe and subtropical areas whereas it is cultivated as spring crop in northern Europe and more continental areas. Because of its ability to get along with only of precipitation, C. abyssinica is considered to be relatively drought tolerant. Cultivation is possible up to an annual precipitation of . Crambe has modest demands regarding soil properties, it tolerates soil pH from 5.0 to 7.8. Low soil depth and a high stone and gravel content decrease drought tolerance. Yield levels vary widely at in Russia, in the U.S. and in Germany. Crambe abyssinica can be easily inserted in crop rotations with a requirement of 1600 growing degree-days. Its rotation contingent should not exceed 25%. Because of similar soil requirements and increased soil borne pathogen pressure, cultivation directly after other Brassicaceae species should be avoided. Also to be avoided is cultivation after artificial grassland and fallows because these will enrich the soil seed bank with weeds and there are few pre-emergence weed management methods available. == Use ==

Crambe abyssinica is cultivated for a wide range of industrial purposes. The interest lies mainly in the high erucic acid content (55-60%) of its seed oil, and makes the crop a competitive option to other oil plants as industrial rapeseed. The composition of crambe oil gives this product several special traits, such as high smoke point, good wettability of different materials and high viscosity. In addition, its oil has a higher biodegradability than mineral oils. Unfortunately, the crambe seed shred also contains toxic compounds such as glucosinolates, tannins and inositol phosphate. The use as forage is therefore very limited. The incorporation rate of crambe by-products into animal feed should not be higher than 5% for growing-finishing pigs, 15% for dairy cows, and 19% for sheep. It is not recommended to feed poultry. A possible new use for crambe could be biofuels since the oil composition is suitable for processing. == Current and future breeding efforts ==

Genetically, C. abyssinica has a set of 2n=90 chromosomes and is hexaploid. Thus, improvement of cultivars through selection is difficult to achieve. A new source of variation could be found in the related taxon Crambe hispanica. Recent efforts are found in the field of gene technology. To overcome the limited genetic variation, gene technology has been used in recent years to improve different important agronomic traits of crambe. Site-directed mutagenesis could be another tool for further improvement of the crop. However, the genetic control of many agronomic traits are unknown, thus the potential for genetic improvement is limited at the moment. Additionally further research aims to assess the potential of using the seed cake in protein-based plastic production and to find further uses for the whole plant. ==See also==