Illinois Field Crop Applicators Practice Test

True or false: Herbicide combinations can be used to minimize carryover and crop injury?

1. True

2. False

3. Only in pre-emergence

4. Only for broadleaf weeds

The correct answer is: True

Using herbicide combinations can indeed minimize carryover and reduce the risk of crop injury. This approach is based on the principle of integrated pest management, which aims to use multiple strategies to enhance efficacy while minimizing negative impacts on the environment and neighboring crops. When different herbicides are combined, they can have varying modes of action and persistence in the soil. This diversity helps to break the cycle of resistance that weeds can develop against a single type of herbicide. Additionally, using combinations can label the combined application as having a lower overall dosage per individual product, significantly reducing the risk of phytotoxicity to crops. Furthermore, by applying combinations, the risk of herbicide carryover is also minimized, because the varied components can degrade at different rates. This ensures that no single herbicide remains in the soil long enough to potentially harm subsequent plantings. In the context of the other options, the statements that imply limitations (like only in pre-emergence or only for broadleaf weeds) do not hold true, as herbicide combinations can be effective across various timing and target weeds, not just restricted to a specific scenario.