Common thorn apple
The leaves of the common datura are dark green on top, long-stalked, ovate, pointed, lobed and sometimes very large (20 cm in diameter). The species is characterized by a great variability in appearance. Depending on nutrient, water, and competition conditions, growth height at seed maturity can vary from a few centimeters to more than 150 cm.
The trumpet flowers stand upright in the branch forks. From them a characteristic densely spiny, walnut-sized capsule is formed, in which deep brown to black seeds are found. The ripening of the fruit capsules extends into September and October.
The common datura has become an important weed only in the last decades. An increased occurrence was first detected in the 1990s in eastern Lower Austria and northern Burgenland, and currently a further densification of populations can be observed there. For several years, occurrences of the datura have also been known in fields in the southern provinces (Carinthia, southeastern Styria).
Outside agricultural areas, the species mainly colonizes nitrogen-rich ruderal meadows (garbage dumps, compost heaps, urban fallow land, abandoned gardens).
As a warm sprout, the common datura emerges relatively late and can therefore be found in fields, especially in summer annual crops such as corn, soybean, potato, sunflower, millet, but also in field vegetables.
Especially in field crops with a low growth height, the common datura can develop an enormous competitive power and cause high yield and quality losses. Much more problematic is the fact that the entire plant is highly toxic, as it contains organic compounds (tropane alkaloids). Contamination also occurs when seeds come into contact with plant parts and plant juices of the (green) datura during harvesting. Relatively small amounts of these alkaloids, when ingested with food, can cause poisoning (sensory deprivation, nausea, drowsiness, respiratory paralysis) in humans and animals.
Prevention and control
- Crop rotation: ensure alternation of winter tillage and summer tillage.
- Crop stand control after weed control, before stand closure, and possibly before harvesting.
- Removal of individual plants or smaller populations best by pulling out, pricking or cutting off
- Selection and use of effective herbicides in the crops (see list of plant protection products approved in Austria)
Last updated: 22.11.2021