Illinois Field Crop Applicators Practice Test

True or false: The following steps lead to maximizing the occurrence of herbicide resistant weeds - 1. scouting regularly 2. using mixed herbicides with multiple modes of action 3. cleaning off tillage equipment before leaving a field.

1. True

2. False

3. Only step 1 is effective

4. Only steps 2 and 3 are effective

The correct answer is: True

The statement that the listed steps lead to maximizing the occurrence of herbicide resistant weeds is false. Scouting regularly is indeed a critical practice in weed management. It helps identify weed populations early, assess their density, and determine management needs. However, when done in isolation without other effective strategies, it does not contribute to minimizing the risk of herbicide resistance. Using mixed herbicides with multiple modes of action is a recommended practice for managing herbicide-resistant weeds. This approach reduces the chances of any one weed species developing resistance because the different modes of action target various physiological pathways in the weeds. Therefore, this step is effective in preventing the selection of resistant populations. Cleaning off tillage equipment before moving between fields is also essential for preventing the spread of weed seeds and propagules. This practice minimizes the chance of introducing resistant weeds from one location to another. In summary, while the steps listed are beneficial for a holistic weed management strategy, the phrasing of the question suggests that they increase the occurrence of herbicide-resistant weeds, which is not accurate. Therefore, the correct understanding is that the steps mentioned do not collectively maximize herbicide resistance but rather contribute to its management when implemented correctly.