Articles

The History of Herbicide Use For Weed Management on the Prairies

Author(s): F.A. (Rick) Holm and Eric N. Johnson

Summary: For the past 60 years, herbicides have played a vital role in crop production in western Canada. Their use has allowed for significant diversification in crop types and has triggered a major shift towards more soil- and water-conserving and energy-efficient farming systems. Many new herbicides were discovered and developed in the 1960s and 1970s, but the herbicide “golden era” appears to be over. In recent years, dramatically fewer new herbicide registrations and ever-increasing numbers of herbicide-resistant weeds make the herbicide tools we already have increasingly valuable.

_{Citation: Holm, F.A. and Johnson, E.N. 2009. The history of herbicide use for weed management on the prairies. Prairie Soils and Crops 2:1-10. [http://www.prairiesoilsandcrops.ca]}

Global Herbicide Development – Opportunities and Constraints

Author(s): Hansjoerg Kraehmer and David Drexler

Summary: Herbicides have been essential tools in agricultural production for decades. With the global introduction in Canada of herbicide tolerant (HT) crops in 1996, agriculture has changed drastically. Today three HT systems now account for more than 90% of Canadian canola production. HT systems have not yet achieved acceptance in a few major crops like wheat (Triticum aestivum L.), barley (Hordeum vulgare L.) and pulse crops.

_{Citation: Kraehmer, H. and Drexler, D. 2009. Global Herbicide Development – Opportunities and Constraints. Prairie Soils and Crops 2:11-16. [http://www.prairiesoilsandcrops.ca]}

Herbicide Resistance in Weeds: Influence of Farm Practices

Author(s): Hugh J. Beckie

Summary: Herbicide-resistant weeds, particularly wild oat, green foxtail, kochia, and chickweed, are growing problems across the Prairies. Currently they affect over 10 million acres (4 M ha) and trends suggest they may soon affect a lot more. Cropping system diversity is the foundation of proactive weed resistance management. Weed surveys, conducted over the past decade, have shown that the risk of weed resistance is greatest in fields with only a cereal-based rotation.

_{Citation: Beckie, H.J. 2009. Herbicide Resistance in Weeds: Influence of Farm Practices. Prairie Soils and Crops 2:17-23. [http://www.prairiesoilsandcrops.ca]}

Best Management Practices for Herbicide Application Technology

Author(s): Tom Wolf

Summary: Producers are continually striving to find the best ways to achieve Effective, Economical, and Environmentally Friendly spray applications. Together these are known as the three Es of spray application. In practical terms, the three Es mean that a pesticide has to do a good job controlling the targeted pest and permit fast, inexpensive, low-drift spray operations. It is quite possible to be able achieve one or two of these goals in most spraying operations, but meeting all three together requires compromise.

_{Citation: Wolf, T. 2009. Best Management Practices for Herbicide Application Technology. Prairie Soils and Crops 2:24-30. [http://www.prairiesoilsandcrops.ca]}

Management of Weeds Within Tillage Systems: What Have We Learned From Prairie Weed Surveys?

Author(s): Julia Y. Leeson and A. Gordon Thomas

Summary: Weed surveys conducted in the Prairie Provinces from 2001 to 2003 indicate that most producers are doing a good job managing their weeds no matter what type of tillage system they are using. While there are differences in weed populations in the different tillage systems these variations are as much a function of other management decisions as they are to differences in tillage practices. For example, more use of herbicides in the no-till systems would be expected to contribute to lower weed densities in these systems.

_{Citation: Leeson, Julia Y. and Thomas, A. Gordon. 2009. Management of Weeds within Tillage Systems: What have we learned from Prairie Weed Surveys? Prairie Soils and Crops 2:31-37. [http://www.prairiesoilsandcrops.ca]}

Current Biological Weed Control Agents - Their Adoption & Future Prospects

Author(s): Susan M. Boyetchko, Karen L. Bailey, and Rosemarie A. De Clerck-Floate

Summary: Traditional agricultural practices have generally focused on herbicides, mechanical, and cultural methods as the main tools for weed management. Although these methods have served crop production well, it is important to recognize that there are scientists in Canada, and around the world, testing the potential of using living organisms, like insects, fungi, and bacteria, as biological control agents for weed management.

_{Citation: Boyetchko, Susan M. and Bailey, Karen L. 2009. Current biological weed control agents - their adoption and future prospects. Prairie Soils and Crops 2:38-45. [http://www.prairiesoilsandcrops.ca]}

Weed Seed Banks: Biology and Management

Author(s): Robert H. Gulden and Steven J. Shirtliffe

Summary: Weed seeds don’t germinate the moment they fall off the plant. Over time they have adapted various methods to remain dormant in the seed bank until conditions are favourable for germination. The seed bank, the place where seeds collect or remain until germination, is an important part of the life cycle of weeds In annual, and some perennial weed species, that reproduce by seed only, seed banks are the sole source of future weed populations.

_{Citation: Gulden, Robert H. and Shirtliffe, Steven J. 2009. Weed Seed Banks: Biology and Management Prairie Soils and Crops 2:46-52. [http://www.prairiesoilsandcrops.ca]}

Integrated Cropping Systems for Weed Management

Author(s): K. Neil Harker and Robert E. Blackshaw

Summary: Integrated cropping systems are becoming more popular on the Canadian Prairies. Research that documents weed management, crop production, and the economic benefits of single and combined optimal agronomic practices is on-going and is currently being adopted by forward-thinking and innovative growers. These weed management approaches have proven to be effective. There are however, plenty of opportunities to study and improve current systems at both research and farm levels.

_{Citation: Harker, K. Neil and Blackshaw, Robert E. 2009. Integrated Cropping Systems for Weed Management. Prairie Soils and Crops 2:53-63. [http://www.prairiesoilsandcrops.ca]}