Even if you have the smallest garden, you will be familiar with the problems posed by weeds. It does not take much imagination then to realise the scale of the problem for farmers and that is why ENDURE has been involved in extensive work on one of our most common pests.
Besides the work of the integrated weed management case study, ENDURE has a team of researchers devoted to weed biology and management. The team (Research Activity 4.5) is led by Niels Holst from Aarhus University, Denmark, but has a truly international flavour, with members from the USA, Japan and Australia.
Given its aim of better understanding weed biology and management, the team is creating two tools - one for weed modelling (WeedML) and the Weed Traits Database (WTDB) - in addition to conducting phenology experiments. We interviewed Niels to find out more.
QUESTION: Why such a focus on weeds?
NIELS HOLST: Wherever man sets aside an area for a certain purpose, soon weeds will interfere with that purpose. Weeds are inevitable. In agriculture, herbicides were once an easy solution to this problem but with the advent of herbicide-resistant weeds and public concern about pesticides in general, weed control must be based on a more diverse range of control measures. The integration of different weed control measures must be based on a thorough understanding, both of farmer practice and of weed biology. In RA4.5 we are focused on developing tools that will enable researchers and students obtain a better understanding of weed biology.
QUESTION: What are WeedML and WTDB and what are their purposes?
NIELS HOLST (pictured left): WeedML (Weed Markup Language) is a proposed international standard for the description of weed simulation models. It is based on the XML (Extensible Markup Language) standard and enables modellers to collaborate by facilitating re-use, exchange and combination of models. WTDB (Weed Traits Database) is an online database containing estimates obtained from literature on the vital parameters that define the biological traits of weeds (seed longevity, emergence, development, competivity, fecundity). In RA4.5 we have defined together the requirements for WeedML to be a useful tool for our own research and teaching. A first version of the language will be used for teaching at the ENDURE Summer School in June. Furthermore, the members of the group have put the WTDB on the Internet and entered data for 20 European weed species. Since we found that data on phenology (the sequence of plant development stages following emergence) were in general lacking, we are also this year carrying out phenology experiments on two weed species at several location around Europe.
QUESTION: What has been achieved and what are the next steps?
NIELS HOLST: WTDB was presented at the International Weed Conference in Vancouver last year and WeedML was presented at the Annual Meeting of the American Weed Science Society in Orlando this year. Data on the last species is being entered into WTDB just now, and a report with a statistical analysis of the data is due soon. In the meantime WeedML is being polished and prepared for the Summer School, an extension of WeedML to ecological models in general is also being considered.
QUESTION: It’s a very international team, how is this useful?
NIELS HOLST: There are not that many weed scientists around the world and even fewer that use mathematical modelling and plant traits as research tools. Hence collaboration with researchers from outside Europe has been very useful. ENDURE did not pay for these overseas guests to attend our workshops. They found the workshops so interesting that they found funding themselves and travelled long distances to participate. One of these members is even a teacher at the ENDURE Summer School.
QUESTION: How can people find out more?
Some of the weeds in question
|Any European is probably familiar with this weed. Its official name is Cirsium arvense , but it goes under a host of others, most commonly the creeping thistle. In North America it is often called the Canadian thistle, a bit misleading as it is native to Europe and northern Asia. It has long been considered a weed, in fact in the UK it was officially described as an ‘injurious weed’ with the passing of the Weeds Act in 1959. It is a tall herbaceous perennial, capable of reaching 1m or more and forms large colonies from its underground root system. Some parts are apparently edible, including the roots and, for those armed with strong gloves to harvest them, the spiky leaves. Photograph: Mary Ellen (Mel) Harte, Bugwood.org.|
|Ambrosia artemosiifolia , better known as common ragweed, is a danger not just for farmers but also for the general public thanks to its allergenic pollen. Originating in North America, it is considered an invasive species in several European countries, including France, where INRA estimates its pollen causes allergies in up to 12% of the population in affected areas, Hungary, Slovakia and the Czech Republic. It is also found in Japan, where it is known as butakusa, or pig grass. It is a highly competitive weed and can have significant impacts on crop yields. Populations resistant to herbicides have been reported. Photograph: Theodore Webster, USDA Agricultural Research Services, Bugwood.org.|
|Alopecurus myosuroides , commonly known as blackgrass, has been identified by ENDURE partner Rothamsted Research as one of the most damaging weeds of winter cereals in England. It is not so much the fact that individual plants are particularly competitive, but the densities in which it can occur: Rothamsted says densities of more than 500 plants per square metre frequently occur, causing severe yield losses. To compound the problem, herbicide resistance is common. In fact, the UK Weeds Resistance Action Group says that its random survey conducted in 2002 indicated that resistant blackgrass occurs on virtually every farm in England where herbicides are used regularly for its control. Photograph: Richard Old, XID Services Inc., Bugwood.org.|