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Working Group Meetings
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Reading 2003 |
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Minutes from EWRS Working Group Workshop
Germination & Early Growth
19th 20th September 2003
University of Reading
Present: Alistair Murdoch, Lars Andersson, John Cardina,
Bo Melander, Adam Davies, Ed Luschei, Jack Dekker, Karl Hartmann, Nicholas
Peters, John Teasdale, Camilla Moonen, Musa AlAllgi, Harald Albrecht,
Diane Lyse Benoit, Frank Forcella, Ahmet Uludag, Peter Lutman, Ilse A
Rasmussen, Kirsten Semb Třrresen, Andrew Mead, Maurizio Sattin and Andrea
Grundy.
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The working group participated in a fascinating tours of
firstly the seed science facilities at the University of Reading ( http://www.apd.rdg.ac.uk/Agriculture/
) and secondly Herbiseed, currently the largest suppliers world wide of
weed seeds ( http://www.herbiseed.com/ ).The group are grateful to
Alistair Murdoch and Richard Ellis at Reading University and Martin Parham
and staff at Herbiseed for arranging these visits which were enjoyed by
all.
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Andrea Grundy gave a brief summary of working group
activities up to the present time including:
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Bo Melander gave a brief summary of the physical and
cultural weed control working group activities up to the present time
including:
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First formed 1994 and holds biennial workshops
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206 members have expressed interest in this very active
group and proceedings of previous workshop in Pisa 2002 can be viewed/downloded
at http://www.ewrs.org/pwc/index.html
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The next workshop will be held on 6-10 March Lillehammer,
Norway, 2004. Details can be seen at
http://www.ewrs.org/pwc/2004_meeting.htm
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Interaction between this working group and “Germination
and early growth” are important because timing of weed emergence and early
growth stages are vital to the efficacy of many physical and cultural
methods of weed management
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Peter Lutman gave an overview of the EWRS working group
crop-weed interactions.
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This group started in the early 1990s as a result of
increased interests in the effect of weeds on crop growth and predictions
of yield loss.
http://www.ewrs.org/ewrs-cwi.htm
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The group have also collaborated on joint experiments
and have frequent workshops. The last meeting was held in Viterbo in April
2003.
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The group is now concerned with issues relating to weed
management and its long-term consequences including population dynamics,
competition, responses of weeds to crops and decision support systems.
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Knowledge of the variation/distribution of early weed
seedling growth and plant size would provide important input based on the
very early stages of a weed infestation that may then contribute to
decision making.
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All members of the group gave a brief summary/presntaion
of ideas for new experiments. These were grouped into four themes:
- Germination through to 2-3 leaves (ie end of the “seed dependant growth
phase”)
| Pre-emergence growth (1) |
| Phenology/growth rate for seedling coming up on different days (11) |
| Time to first emergence – duration of cotyledon phase (17) |
| Early seedling growth (18) |
| Pre- and early post-emergence in relation to seed age and environment (26) |
| How does the distribution of seeds in the soil profile affect seedling
emergence? (19) |
- Amending the seedbed (in particular the uppermost
layers by cultivation, soil type, cover crops etc..)
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Spread of emergence in relation to cultivation (3)
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Effects of cultivation (5)
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Ways of manipulating emergence (6)
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Amendments which affect emergence (14)
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Seedbed effects on emergence (21)
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Soil type effects on emergence (24)
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Resolve substrate problems on current expt…..(12)
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Seed variability (population, maternal environment, GxE
etc…)
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Persistence (2)
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Maternal environment (4)
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Ways of manipulating emergence (maternal environment
????) (6)
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Seed to seed variation in populations (9)
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Growth rates of “after-ripened” seeds (13)
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Effects of the environment on seed characteristics (16)
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Early seedling growth (seed age) (18)
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Why do seeds from different places vary ?(20)
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Pre and early post emergence (age, environment etc…)
(26)
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Germination process/physiology
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Oxy-hydro-thermal time (8)
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Dormancy through to emergence (10?)
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Seedbank size..how does % emergence vary (23)
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(22) What can we do with our existing data?
(25) Can we control uniformity of emergence?
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The working group members split into groups according to their interest in the
four themes and then reported back to the rest of the group on preliminary ideas
for simple collaborative study. Following these presentations collective
decision was made to prepare protocols for two ideas primarily looking at:
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Germination through to the 2-3 leaf stage
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Amending the seedbank through cultivation
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Timescale - Maurizio Sattin and Ilse Rasmussen/Alistair
Murdoch agreed to prepare a simple summary describing the experimental protocol
discussed in each of their respective discussion groups. These will be
circulated to all working group members for comment end of October 2003. WG
members are strongly encouraged to make suggestions in order to develop the
final agreed protocols over the coming weeks. The experiments will ideally
commence autumn 2004, however preliminary investigations into methodologies can
start as and when appropriate. WG members who would like to participants in the
two experiments (not compulsory!) will need to express their commitment to take
part in either one or both by the end of 2003 so that planning can start and
quantities of seed calculated.
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Collective populations Alistair Murdoch agreed to make seed
characterisations of the study populations (autumn 2004). Diane Benoit/Camilla
Moonen agreed to investigate and write up some ideas on possibilities for
measuring seed size/weigh/shape of study populations (using image analysis
software etc..). Possibly also contact Renée Bekker regarding useful traits that
could be easily measured. As with the previous collective study, ripe seed would
need to be collected from established, agricultural populations from a range of
individuals. Protocol from previous experiment for harvesting and storage will
be circulated.
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Website – update suggestions include providing link to Weed
Research paper and updated members details. E-mail addresses as “jpeg” files.
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EWRS Training & Education website. Weed portal (online
textbook) is now underway which will provide lecture and presentation material
on all aspects of weed science. Working groups will be asked whether they are
willing to nominate an “associate editor” for the collation of material relevant
to subject area of their working group. More information and a template on this
activity will be provided later. In the meantime, further details can be found
at: http://www.ewrs.org/et/index.html
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EWRS symposium, Bari 2005. As with the 2002 symposium in
Papendal, working groups will feature strongly in the structure and organisation
of sessions. The first circular will be out shortly.
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Andrea agreed to collate all the remaining data from the
existing collaborative experiment and update those who participated by early
November 2003. Andrea has constructed a water release cure for the common
substrate and will supply this to Frank Forcella as soon as possible.
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Next EWRS working group meeting. There will be no fixed
working group meeting in 2004 as there are already a number of weed meetings
planned. The suggestion is that Andrea will organise informal meetings for
working group members to get together that are planning to be present at either:
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EWRS physical & cultural weed control workshop in
Lillehammer, Norway (6-10 March),
http://www.ewrs.org/pwc/2004_meeting.htm
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4th IWSC, Durban 20-24 June
http://www.iwsc2004.org.za/
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XIIth International Conference on Weed Biology 31 August – 2
September 2004, Dijon.
http://www.inra.fr/Internet/Centres/Dijon/malherbo/colloque/colloque1.htm
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Back to Meetings page
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