A beginner s guide to harvest weed seed control Today s presenters are Dr Michael Walsh, AHRI Maurie Street, GOA

Transcription

1 Welcome to the third of a series of 3 GRDC weekly webinars on weed related topics A beginner s guide to harvest weed seed control Today s presenters are Dr Michael Walsh, AHRI Maurie Street, GOA This Webinar will start at the following times 3.00 PM (QLD/NSW/VIC/TAS) 2.30 PM (SA) 1 PM (WA)

2 Housekeeping On your screen on the top right you will see a small red arrow pointing to the left. If you click on this, this will open up a chat box to ask questions & audio etc. We are using chat box for questions, audio questions are muted to maximise sound quality. Questions will be relayed by the moderator. Questions (except for clarification) will be left until the end of the presentation and repeated by the moderator Should you drop out, please go to joinwebinar.com and enter the webinar code (should also be on the confirming s you have been sent). If you are having audio difficulties, you will see a place to select telephone on your chat box this will come up with the phone number and log in pin to join the webinar by phone. Phone number is , code and a individual pin number. Moderator: Erica McKay GRDC Project code ICN00016

3 Welcome to the third of a series of 3 GRDC weekly webinars on weed related topics A beginner s guide to harvest weed seed control Today s presenters are Dr Michael Walsh, Australian Herbicide Resistance Initiative Maurie Street, Grain Orana Alliance

4 Today s Agenda Why consider harvest weed seed control? Weed seed retention in northern region What options are available for seed destruction? How to effectively burn narrow windrows

5 Why consider harvest weed seed control? Annual ryegrass (plants/m2) Herbicides + HWSC Herbicides Reduced herbicide reliance Cropping flexibility Increased production!!

6 Harvest weed seed control Its all about seed retention at crop maturity Annual ryegrass Wild radish Wild oats Brome grass

7 Harvest weed seed control Because of weed seed retention at crop maturity Weed species Retained seed* (%) Annual ryegrass 88 Wild radish 99 Brome grass 73 Wild oats 85 * Seed above harvester cutting height (15cm)

8 Targets in Nth NSW & Queensland Weed Proportion of seed above harvest height (%) Wheat Chickpea Sorghum Sowthistle Fleabane Barnyard grass Bladder ketmia Wild oats Turnip weed African turnip Feathertop Rhodes 100

9 Harvest weed seed control Stop reseeding!

10 Getting the seeds into the header? Harvest as low as possible, cm (beer can height) Early harvest in problem paddocks Swathing/windrowing to increase weed seed retention

11 Chaff carts Up to 85% of annual ryegrass and wild radish seed collected Conveyor belt chaff transfer system Shorter burning times Easy attachment 200 new chaff cart systems in WA since 2010

12 Chaff management Line chaff heaps up across paddock Or concentrate in paddock areas

13 Chaff management? Grazing

14 Chaff management? Lot feeding

15 Chaff management? Autumn burning

16 Burning chaff heaps Setup firebreak Light on down wind side

17 Tram tracking Place chaff on wheel tracks Mulching effect dependant on residue and rainfall Concentrates 90 95% of annual ryegrass on to tram lines Need for control?

18 Harrington Seed Destructor Ray Harrington Based on a cagemill used in the coal industry

19 Cagemill results >90% kill of annual ryegrass seed No effect of chaff type 100 Seed survival (%) Cagemill speed (rpm)

20 Harrington seed destructor

21 Harrington seed destructor Annual ryegrass Wild radish Wild oats Brome grass Seed destroyed in chaff (%)

22 Harrington seed destructor Highly effective chaff processing system No need for post harvest operations Retention of all harvest residues

23 Narrow Windrow Burning Establish windrows at harvest Burn residues in autumn 99% weed seed destruction Most WA growers use this technique Chute fitted to harvester Concentrate residues at harvest Burn windrows in autumn

24 A1 Which option is for me? HWSM option Effectiveness Up front cost* On Going cost Effect on ground cover Change in labour HSD High $250,000 R & 5%?? Nil nutrient impact Low Little change Chaff carts High $80,000 Small R& M Moderate nutrient Moderate Burning chaff heaps Tram Track?? Less than others $15,000 Small R & M Low nutrient impact Low Little change Windrow Burning High $200 No R & M $ nutrient impact# Highest Highest *Estimated purchase costs # Most cost in K replacement

25 Slide 24 A1 Tram tracking systems can be as cheap as $200. There is removal of chaff residue from the field as the chaff material is concentrated in the tram lines. This also means that there is nutrient removal from the field as well. Author, 17/06/2014

26 Tips and Tricks for Windrow Burning Plan Ahead at all phases Deciding to harvest for windrow burning 4 days into harvest will not give produce the desired outcomes

27 Header set up Chute design and mounting Simple and easily taken on and off Must be NARROW WINDROWS Dropping just the spinners off is not good enough

28 Source: Walsh & Newman (2007)

29 What paddocks to target? Low weed burden best results Dirty paddocks need more than one year Persistent seed banks Dirty paddocks may well need more done Swathing Silage or hay Brown manure Source Hugo Grassier

30 Which paddocks to target? For windrow burning Start with pulses or canola Lowest risk of fire escapes However 1 year in 4 or 5 will not be enough Lower yielding wheat crops < 3 t/ha, when confident Barley has a leafy stubble and greatest fire escape risk not recommended

31 Talk to the header driver Understand what needs to be achieved Harvest low enough to capture weed seeds Drivers have tendency to sneak higher go faster May need to adjust header set up

32 Tell them Do not pull up to a dead stop in the paddock Trash needs to get out of header Blocks up from the back and moves forward Lost time to un block

33 The Business end Burning the Windrows Getting this wrong results in either poor weed control Fire escapes OR WORSE BOTH

34 Weather conditions Ferocity of a fire is related to Temperature Humidity Wind Fuel curing and load Ideal conditions are getting the mix of these right Grassland fire index helpful in identifying good conditions

35 Relative Humidity Wind Speed Curing of Fuel Temperature

36 Relative Humidity iphone App Wind Speed NSW Pocket Fire Found in the App Store Curing of Fuel Temperature

37 Be prepared When conditions are ideal be prepared to go Firebreaks put in Fire permits secured Fire tankers serviced and ready Method to light them Accufire or similar Take opportunities when available particularly for paddocks in need of a good job

38 General rules Start watching the 28 day weather forecast in March for ideal conditions If you start looking early enough there is less need to panic Light a small area first rake a small break in the row and light one you will know soon enough how it is going to go

39 Wind and Water? Light cross wind is best Head or tail winds can push fire over the top and not burn to the bottom Autumn rain on windrows is not ideal but don t panic days of no rain has windrows dry enough Fire can dry some moisture out 26 th April mm total rain since January 1 st, 120mm last 4 weeks

40 Prioritise depending on crop For canola or pulses crop go early Little chance for fire escape Less biomass in windrow to create heat in adverse conditions Cereal stubbles Light crop/ windrows These can be difficult burn while conditions are still mild enough to get good heat Cereal stubble heavy Generally need to delay to minimise risk of escape Significant fuel will easily generate heat to dry rows out

41 Didn t quite go to plan? Not achieving a good burn is not failure A 60cm strip of un controllable weeds is better than 12mt of them Options to patch manage Next years windrows over the same spot kill em then Don t give up either practice makes perfect

42 Questions & Discussion Further resources GRDC Weed capture videos minimanual/section 6 Managing weeds at harvest AHRI website Targeting weed seeds at harvest brochure Harvest weed seed control booklet seeds_at_harvest_brochure.pdf eed_seed_control_booklet_2013_version.pdf Windrow chute design ute_cad_drawings_oct13.pdf