Chapter 14: Applied Herbicide Physiology and Movement
14.15 Summary
Herbicides can be a very important tool in a long-term weed management plan. To maximize their success we looked at important concepts that need to be considered, including how foliar and soil-applied herbicides are absorbed by plants, the influence of weather conditions and effects of weed growth stages and densities. This is important to minimize crop damage and maximize weed control. Oftentimes what appears to be a herbicide resistant weed population is actually a less than optimal application scenario.
Key Takeaways
Key takeaways from this chapter include:
- Herbicides must be applied at the correct time, in the correct location, and using the correct amount to be effective.
- Plants absorb herbicides through mass flow, contact, or diffusion.
- Contact herbicides damage only plant tissue directly touched by herbicide. Systemic herbicides applied to plant tissue can be translocated from one part of the weed plant to another.
- Environmental conditions such as hot or cold temperatures and soil moisture can influence herbicide effectiveness.
- Weed plant characteristics such as life cycle, growth stage, genetics and population density can influence herbicide effectiveness.
- Once applied, herbicides can have several fates including degradation due to environmental conditions or microbes, metabolism in a plant, runoff in excess moisture conditions, or volatilization.