Survey | Has Italian Cocklebur Invaded Your Farm?
You must have seen “cocklebur” before – those little oval fruits with sharp, barbed hooks on the front, like tiny Velcro. Once ripe, they cling to your clothes and your animals; a walk through the fields can leave your trouser legs entirely covered. Although native cocklebur has grown in China for a very long time, a non-native relative – the Italian cocklebur – has appeared in recent decades. Though closely related to the native cocklebur, it may pose a serious threat to agriculture.
Both the Italian cocklebur and the native cocklebur belong to the genus Xanthium in the family Asteraceae and are annual herbaceous plants. The Italian cocklebur originated in Southern Europe and is now widely distributed across many regions of Europe, the Americas, Asia and Oceania. First recorded in Beijing in September 1991, its range within China has expanded rapidly. It has now reached Liaoning, Hebei, Beijing, Shandong, Shaanxi and Xinjiang, and specimens have been found at Badachu, Shidu, Guanting, Baihua Mountain, the North Sha River, Wali and Miyun in Beijing, where it has become a dominant species in certain areas.
With its low demands on growing conditions, the Italian cocklebur can tolerate prolonged exposure to saline-alkaline soils and frequent waterlogging, often forming dense patches across significant areas of land. Both farmers and scientists have begun to worry: The Italian cocklebur already poses a serious threat to agricultural production and biodiversity conservation in the areas it has invaded.
Research has shown that once the Italian cocklebur establishes itself in fields of maize, cotton, soybeans and other crops, it competes with them for growing space, causing considerable losses – a coverage rate of just 8% can reduce crop yields by 60%. The Italian cocklebur also competes with Solanaceae crops for sunlight during their critical flowering stage, further reducing yields.
In addition, aqueous extracts of the Italian cocklebur’s stems and leaves have been found to significantly inhibit seed germination in maize, oilseed rape, oilseed sunflower and liquorice. They also suppress the germination of seeds from wild plants such as shepherd’s purse, Chinese violet cress, dandelion and Viola philippica.
For livestock, the Italian cocklebur’s fruits are larger than those of the native species, with denser, hooked spines that cling readily to sheep’s wool and are difficult to remove, significantly reducing wool yield.
Because the Italian cocklebur spreads rapidly across northern China, easily forming single-species dominance and posing serious risks to agriculture and livestock, it was added to the Category 3 inbound quarantine pest list in 1997.
Currently, Ms Yue Xiaoxiao at the Beijing Xuanwu Youth Science and Technology Museum is leading a group of schoolchildren passionate about biology and agriculture in a study of the Italian cocklebur’s invasive impact. Through questionnaires, interviews and field visits, they hope to map the distribution of the Italian cocklebur on farms and in villages across Beijing and its surrounding areas (and potentially a wider region) – including where it grows, its growth condition, the area it occupies and its impact on agriculture – to assess the extent of the damage and propose appropriate management measures.
If you happen to live and work on a farm or in a village in or around Beijing and have already observed the Italian cocklebur’s impact on agriculture and the local ecology, you are welcome to join this survey. Farmers and growers in other regions are also encouraged to fill in the questionnaire and join us as citizen scientists. Ms Yue Xiaoxiao and her students also hope to identify typical farms and villages for on-site fieldwork.
If your farm is also affected by other invasive species, please leave a comment below.
How to Participate
Survey Period
July to September 2023
(Italian cocklebur is easier to identify during this period)
Geographic Scope
Farms or villages in Beijing and its surrounding areas
(Participants in other regions are also welcome to fill in the questionnaire)
How to Participate
Fill in the questionnaire (photos can be uploaded)
http://lxi.me/3aq01
Once we receive your questionnaire,
we will contact you via WeChat or by phone
Project Initiated by
Project Support
Text: Yue Xiaoxiao
Editor: Wan Lin