Developments in physical weed control Eric R. Gallandt, University of Maine, USA; Daniel Brainard, Michigan State University, USA; and Bryan Brown, University of Maine, USA

Developments in physical weed control Eric R. Gallandt, University of Maine, USA; Daniel Brainard, Michigan State University, USA; and Bryan Brown, University of Maine, USA

1 Introduction

2 Tillage

3 Physical weed control: overview

4 Tools, weeds and soil conditions

5 Weed-crop selectivity

6 Fundamental problems with cultivation

7 Future research priorities

8 Where to look for further information

9 References

Physical weed control (PWC) refers to the use of a tool or implement to kill a weed seedling, an operation that some authors call cultivation or mechanical weed control. PWC is a foundational practice for organic farmers, and for diversified vegetable farmers, who have concerns regarding herbicide drift and carryover. Intractable cases of herbicide resistance, notably multiple resistance in Amaranthus palmeri and Conyza canadensis, and lack of novel herbicide sites of action (Heap 2014) may inspire a return to PWC by grain and cotton farmers as well.