Survey | Is Italian cocklebur invading your fields?
You will almost certainly recognise cockleburs: oval fruits tipped with hook-like spines that cling to clothing and animals once ripe. A quick walk through the fields can often leave your trousers covered in them. While the native cocklebur has been established in China for centuries, an invasive relative, the Italian cocklebur, has emerged over recent decades. Despite their close botanical ties to the native plant, they pose a serious threat to agriculture.
Italian burdock, like China’s native *Xanthium* species, belongs to the Asteraceae family and is an annual herb. Native to southern Europe, it has since become widely distributed across many regions of Europe, the Americas, Asia, and Oceania. Since its first discovery in Beijing in September 1991, its range within China has expanded rapidly. It has now spread to areas including Liaoning, Hebei, Beijing, Shandong, Shaanxi, and Xinjiang. Within Beijing itself, it has been recorded at Badachu, Shidu, Guanting, Baihua Mountain, Beishahe, Wali, and Miyun, where it has become a dominant species in certain localities.
Because it tolerates a wide range of growing conditions and can endure saline-alkali soils and frequent waterlogging over extended periods, it often forms extensive, continuous stands in certain areas. Farmers and scientists alike are growing concerned: Italian burdock now poses a serious threat to agricultural production and biodiversity conservation in invaded regions.
Research indicates that once Italian burdock enters fields cultivating maize, cotton, or soybeans, it competes with the crops for space and resources, causing substantial damage—a coverage rate of just 8% can slash crop yields by 60%. It also competes with solanaceous crops for sunlight during their critical flowering period, resulting in further yield losses.
Additionally, aqueous extracts of its stems and leaves significantly inhibit the germination of seeds from maize, rapeseed, oil sunflowers, and licorice. These extracts also suppress the germination of seeds from various wild plants, including shepherd’s purse, Oriental wallflower, dandelion, and purple violets.
For livestock, the fruits of Italian burdock are larger than those of native species, bearing denser, hooked spines that readily cling to wool. They are difficult to remove and can significantly reduce wool yield.
Due to the rapid spread of Italian burdock across northern China, where it readily forms a dominant monoculture and causes severe damage to agriculture and livestock, it was listed by Chinese authorities as a Category 3 quarantine pest in 1997.
Currently, Yue Xiaoxiao, a teacher at the Beijing Xuanwu Youth Science and Technology Museum, is guiding a group of primary and secondary school students with a keen interest in biology and agriculture to conduct research on the invasive impact of Italian burdock. Through questionnaires, interviews, and on-site visits, they hope to map the distribution of Italian burdock across farms and villages in Beijing and its surrounding areas (which may extend to a wider region), gathering data on: growing locations, plant condition, area affected, and impact on agriculture, evaluate the severity of the threat, and propose suitable control measures.
If you work or live on a farm or in a village in or around Beijing, and have already noticed the impact of Italian burdock on agriculture and the local environment, we warmly invite you to take part in this survey. Growers and farmers from other regions are also welcome to complete the questionnaire and contribute as citizen scientists. Yue Xiaoxiao and the pupils are also looking to identify typical farms and villages for on-the-ground research.
If your farm is also struggling with other invasive species, please feel free to share your experiences in the comments section below.
How to Participate
Survey Period
July to September 2023
(Italian burdock is easiest to identify during this window)
Geographic Scope
Farms or villages in and around Beijing
(Respondents from other regions are also welcome to fill in the questionnaire)
How to Take Part
Complete the questionnaire (photos can be uploaded)
http://lxi.me/3aq01
Once we receive your submission
we will get in touch via WeChat or phone
Project Initiated by
Project Supported by
Writing: Yue Xiaoxiao
Editor: Wan Lin