9.4 Weed Management Strategies – Control

3. Control

The control strategy for weed management is not to completely eliminate the weed population, but rather reducing it to a level to where crops are not going to lose significant yields.   In other words, with control the goal is to minimize the effects of weed pressure on crops.  This is the most common approach in field crop weed management planning.  We will spend the remainder of this book discussing various approaches to weed control.

Weed control varies across a continuum or a spectrum. On one end there might be a poorly managed field with a lot of weed pressure and then on the other extreme, there could be a field with excellent control and very few weeds present.  The challenge is that sometimes the excellent control is not always the best. The amount of inputs and resources it takes to achieve a perfectly managed field often costs more money than a farmer will see returned in crop yield.  It may also put extensive pressure on the weeds (which leads to the development of resistant weeds) or be harmful to the environment.  Somewhere in the middle of the weed control spectrum is where farmers find a sustainable balance.

There are five aspects to weed control:

• Prevention Strategies
• Cultural Practices
• Biological Control Methods
• Mechanical Control Methods
• Chemical Control Methods

Integrated Weed Management (IWM) utilizes several of these methods over time to keep weed populations under control, minimizing resistance from building up and protecting both the environment and profit margins.