Non-Chemical Weed Management Workshop

The Non-Chemical Weed Management workshop was developed by Dr Charles 'Merf' Merfield in the early 2000s. It has expanded over the years from an hours presentation to a full day workshop giving a complete overview. It is also now run annually alternating between the South Island (at Lincoln University) and the North Island (various locations). The 2024 workshop will most likely be in Pukekohe. If you want to be notified of the next workshop please subscribe to the FFC Events notification list. The information below gives an outline of the workshop.

Presented by Dr Charles 'Merf' Merfield, an international researcher on non-chemical weed management and the leading scientist and consultant in A-NZ. Merf is head of the BHU Future Farming Centre and Merfield Agronomy Ltd. plus co-owner and director of PhysicalWeeding.

Merf has more than 30 years experience in non-chemical weed management. He started his career helping re-establish Sunnyfields organic vegetable farm in the UK after the previous manager had walked off having lost his war with the weeds. In a sink or swim moment, he devised a new weed management strategy which turned around the weed problem in just two years. From the UK he came to Aotearoa New Zealand for a working holiday from which he is unlikely to return. He worked extensively at Harts Creek Farm in Canterbury as they expanded their organic cropping systems across multiple farms.

He has also invented, designed and built a wide range of weeding machinery including an optimised naturally aspirated flame weeder, re-invented the direct-fired steam boiler and repurposed it for ag / horticultural use, the 4 Wheel Hoe, false seedbed cultivators, interrow hoes, basket weeders and even a new toolbar clamp!

He has over 40 publications on non-chemical weed management including peer reviewed papers and book chapters, conference proceedings and extension publications including though leading articles on the future of weed management. For example, 'Redefining weeds for the post-herbicide era' and 'Could the dawn of Level 4 robotic weeders facilitate a revolution in ecological weed management?' See his research page and the FFC website for more examples and additional information.

Who should attend?

The primary audience is horticultural and cropping / arable farmers & growers as it is these production systems that have the largest challenge with weeds. Perennial crop (e.g. vines, apples) producers will also benefit with one section dedicated to perennial crops (see below). There is some benefit for livestock / pasture systems in terms of the overall concepts of non-chemical and integrated weed management plus herbicide resistance. Consultants and advisors working with farmer and grower clients, particularly in cropping, will gain considerable benefit, especially regarding the latest technologies. Scientists, especially those working on the transition away from agrichemicals, will gain valuable insights.

The content assumes a reasonable level of understanding and practical experience of commercial agriculture and horticulture systems including weed management.

This is a really full on and intense workshop - bring your thinking head!

The benefits of attending.

The day gives a systematic overview of non-chemical weed management, providing information on the changing context of weed management, the fundamentals of weed biology and ecology, through to practical know-how of tools and techniques that farmers and growers can use themselves. See below for more detail on the topics covered. Due to the huge size of the topic this is 'only' and overview and cannot get into the detailed of non-chemical weed management in every crop.

Attendees will be given a colour hardcopy booklet containing all the presentation slides (in handout format). Attendees can also download PDF versions of the presentations after the workshop.

Some comments from the previous weed management workshop participants

"Great overview and backed up by robust science"
"Highly useful, time to implement theory into practice"
"At the cutting edge"
"Enthusiastic presenter"
"Great discussions"

Registration

Cost for the 2024 is yet to be confirmed but will be in the ballpark of NZ$350 +GST. It will include the printed versions of the presentations and all catering, including tea and coffee on arrival, morning and afternoon smoko and lunch.
Registration wiil be essential as places are limited.

Topics covered

Below are the topics from the 2023 workshop. Once again there was signficant updating and expansion on previous years.

Part 1: The Big Picture: A Little Context
Context - weed management and the planetary challenges
The new soil health paradigm of plant root exudates
Context - the changing attitudes to weeds
Q&A session
Changing attitudes to weeds
Redefining weeds for the post-herbicide era
Integrated weed management (IWM), how herbicide and non-chem. weed management relate
The ESR concept of system redesign
Agroecological weed management is the future
Discussion / questions and answers

Part 2: Herbicide resistance
Some terminology
Global herbicide resistance
NZ herbicide resistance
Mutation rate and mutations per ha
How herbicide resistant weeds occur
Herbicide resistance risk factors
Where do they come from?
Beating herbicide resistance
How do I know if I have herbicide resistant weeds?
Discussion / questions and answers

Part 3: Think like a weed: key biological and ecological knowledge
Just how good it can get!
Lifecycles and morphology
Seeds, seeding, the seedbank, dispersal, longevity and dormancy
Q&A session
The ‘bud based perspective’
Dedifferentiation - zombie plants
Therophytes
Discussion / questions and answers

Part 4: Doing it in the field - the weed management hierarchy
The non-chemical weed management hierarchy
Weed seed rain - stopping it
Q&A session
Rotations what they can and can’t do for weed management
Q&A session
The relevance, and lack of relevance, of soil conditions inc nutrient status for weed management
Q&A session
The role of crop and pasture choice and grazing management
Discussion / questions and answers

Part 5: Plants vs. weeds
Diversity is the answer
Plant mixtures - intercropping - are the answer
Subsidiary (cover crops)
Discussion / questions and answers

Part 6: Plants vs. weeds in perennial crops
"The death zone has gotta go"
The alleyway / interrow
The crop row / intrarow
It's all about root interactions
Discussion / questions and answers

Part 7: Pre-emergence weeding
Pre-crop-emergence weeding (tillage)
False and stale seedbeds
Thermal weeders - flame, steam and electrothermal
Sowing, planting & related techniques
Nutrient placement and timing
Discussion / questions and answers

Part 8: Post-emergence weeding - Contiguous weeders
How mechanical weeders kill
Row spacing and un-hoed area
Crop weeder hierarchy
Contiguous weeders
Discussion / questions and answers
Smoko - refreshments provided

Part 9: Electrothermal and perennial crop weeders
Electrothermal - our get out of jail card
Q&A session
Physical perennial crop weed management
Discussion / questions and answers

Part 10: Robotic weeders and the future
The 4 Levels of robotic weeders
Ecological weed management by robot
An interesting future
Discussion / questions and answers

Part 11: Post-emergence, incontiguous weeders
Weeding in annual crops - arable and vegetables
The importance of accuracy
Incontiguous weeders
Pedestrian wheel hoes
Ridge weeders
Discussion / questions and answers

Part 12: Post-emergence, incontiguous weeders an harvest weed seed control
Intrarow weeders: non-discriminatory and discriminatory
Selective thermal weeding
Harvest weed seed control (HWSC)
Hand weeding
Final discussion / questions and answers
Depart