Harvest Weed Seed Control. Breanne Tidemann University of Alberta

Transcription

1 Harvest Weed Seed Control Breanne Tidemann University of Alberta

2 Acknowledgements Dr. Neil Harker and Dr. Linda Hall Eric Johnson Students and technical staff UofA weeds lab AAFC Lacombe Agronomy and Weeds Crew AAFC Lethbridge Weeds Crew and Dr. Bob Blackshaw

3 Why are we interested in Harvest Weed Seed Control? Abbreviated as HWSC Herbicide resistance Present and increasing in Western Canada and Alberta Evolution of glyphosate resistant kochia Expected evolution of more glyphosate resistance Lack of new herbicide modes of actions New herbicides, act on old targets in the plant 35 Introduction Time of New Herbicide Sites of Action 30 Number of Sites of Action Year Dr Ian Heap WeedScience org 2014

4 What is Harvest Weed Seed Control? New method of weed control developed in Australia Prevention of viable weed seed return to the field at harvest Not intended as a standalone Numerous ways of conducting HWSC High levels of adoption across Australia Effective

5 Types of Harvest Weed Seed Control Narrow Windrow Burning Direct Bale Chaff Cart Others: chaff deck (weed seeds on to tramlines), windrow rotting

6 Harrington Seed Destructor Weed seeds processed through an opposing cage mill Impact of the mill on the seeds renders them unviable Extremely effective on wild radish and annual ryegrass Residue is left on the field (spreader at the back) Cost prohibitive: $205,000 CAD Further developments: Cage mill integrated into back of the combine Walsh et al. 2012

7 Canadian Research Weed biology: Are our weeds compatible with HWSC methods? Are weeds grown/seeded in plots biologically similar to producer fields? Harrington Seed Destructor Efficacy (seed size, seed load, chaff type) Harrington Seed Destructor Field Level Tests

8 Requirements for Weeds to be Compatible with HWSC 1. Weed seeds must be produced at a height from which they are collectible (i.e. above 6 or 15cm in height) 2. Weed seeds must be retained on the plant at the time of harvest. Weed biology study Objective: To determine if these requirements are met by wild oat, cleavers and volunteer canola, and if crop competition effects change retention or height

9 Site Locations 2014 Lacombe, AB St. Albert, AB Scott, SK

10 Materials and Methods Why wild oat, cleavers, and canola? #2,3 and 6 in relative abundance in Alberta Cleavers fastest increasing weed in relative abundance J. Leeson, C. Neeser N. Kimmel and M. Vadnais Weed Survey Series Pub (2012) Increases in herbicide resistance in wild oat and cleavers: expected evolution of glyphosate resistance

11 Materials and Methods Weeds cross-seeded against crops Shatter trays placed between crop rows prior to any seed loss Trays checked and emptied twice/week

12 Materials and Methods Weeds harvested at three times: Wheat Swath timing Wheat Direct Harvest timing Fababean Direct Harvest timing Plants sectioned into four heights 0-15cm,15-30cm, 30-45cm, 45+cm Dried, dry weights measured

13 Materials and Methods Height sections containing seeds threshed and cleaned Retained seeds counted # of seeds lost and percentage of seeds retained calculated

14 Results One year of data: second year in 2015 Not discussing height: Only reviewed in Lacombe Majority of weed seeds produced in collectible range (>15cm) Start with Lacombe In detail Other two sites more quickly Producer fields

15 Lacombe Wild Oat Seed Retention Average Seed Retained (%) Fababean 1x Fababean 2x Wheat 1x Wheat 2x 20 0 Aug 5 Aug 7 Aug 12 Aug 15 Aug 19 Aug 22 Aug 26 Aug 29 Sept 2 Sept 5 Sept 9 Sept 12 Sept 15 Sept 19 Sept 23 Sept 26 Sept 29 Date

16 Lacombe Cleavers Seed Retention Average Seed Retained (%) Aug 5 Fababean 1x Fababean 2x Wheat 1x Wheat 2x Aug 7 Aug 12 Aug 15 Aug 19 Aug 22 Aug 26 Aug 29 Sept 2 Sept 5 Sept 9 Sept 12 Sept 15 Sept 19 Sept 23 Sept 26 Sept 29 Date

17 Lacombe Canola Seed Retention Average Seed Retained (%) Aug 5 Aug 7 Aug 12 Aug 15 Aug 19 Aug 22 Aug 26 Aug 29 Sept 2 Sept 5 Sept 9 Sept 12 Sept 15 Sept 19 Fababean 1x Fababean 2x Wheat 1x Wheat 2x Sept 23 Sept 26 Sept 29 Date

18 Lacombe Three Species Seed Retention Average Seed Retained (%) Aug 5 Wild Oat Cleavers Canola Aug 7 Aug 12 Aug 15 Aug 19 Aug 22 Aug 26 Aug 29 Sept 2 Sept 5 Sept 9 Sept 12 Sept 15 Sept 19 Sept 23 Sept 26 Sept 29 Date

19 Scott Three Species Seed Retention Average Seed Retained (%) Aug 12 Wild Oat Cleavers Canola Aug 15 Aug 19 Aug 22 Aug 26 Aug 29 Sept 2 Sept 5 Sept 9 Sept 12 Sept 16 Sept 18 Sept 23 Sept 26 Oct 1 Date

20 St. Albert Three Species Seed Retention Average Seed Retention (%) Aug 8 Wild Oat Cleavers Canola Aug 12 Aug 15 Aug 19 Aug 22 Aug 26 Aug 29 Sept 2 Sept 5 Sept 9 Sept 12 Sept 16 Sept 19 Sept 23 Sept 25 Date

21 Lacombe Three Species Seed Retention St. Albert Three Species Seed Retention Average Seed Retained (%) Average Seed Retention (%) Aug 5 Wild Oat Cleavers Canola Aug 7 Aug 12 Aug 15 Aug 19 Aug 22 Aug 26 Aug 29 Sept 2 Sept 5 Sept 9 Sept 12 Sept 15 Sept 19 Sept 23 Sept 26 Sept Aug 8 Wild Oat Cleavers Canola Aug 12 Aug 15 Aug 19 Aug 22 Aug 26 Aug 29 Sept 2 Sept 5 Sept 9 Sept 12 Sept 16 Sept 19 Sept 23 Sept 25 Date Scott Three Species Seed Retention Date Average Seed Retained (%) Aug 12 Wild Oat Cleavers Canola Aug 15 Aug 19 Aug 22 Aug 26 Aug 29 Sept 2 Sept 5 Sept 9 Sept 12 Sept 16 Sept 18 Sept 23 Sept 26 Oct 1 Date

22 Producer Fields Placement of shatter trays Seeds collected each week 3 producer fields near Lethbridge: 2- wild oat only 1 wild oat, wild mustard, foxtail barley, sow thistle, barnyard-grass, persian darnel, lamb s quarters Harvested at swath and direct harvest timings % retained determined

23 Producer Field Seed Retention Average Seed Retention (%) Swath Harvest Species

24 Conclusions Variation between sites Environment (heat, precipitation) Competition (volunteer weed population) Same pattern Canola retaining most: Good target for HWSC Cleavers: Swathing may be a valuable tool, variable between sites Wild Oat: Least retention, likely not a good target for HWSC Plots vs Producer Fields Showing same pattern for wild oat, likely not a good target Need other options for wild oat Field scale efficacy of Harrington Seed Destructor Efficacy of Harrington Seed Destructor on seeds of these species

25 Thank You! Questions?