Certified Crop Advisor Practice Exam

Which of the following is least useful for predicting a disease outbreak in crops?

1. Weather conditions

2. Soil tests

3. Field history

4. Pest populations

The correct answer is: Field history

To understand why field history is considered the least useful for predicting a disease outbreak in crops, we can look at the role that each of the options plays in disease management. Weather conditions provide critical information about the environment conducive to disease development. Many plant diseases require specific weather conditions such as moisture, humidity, and temperature for pathogens to thrive and spread. Therefore, analyzing weather patterns can give insight into potential disease outbreaks. Soil tests are essential for assessing soil health and fertility, but they also can indicate factors related to plant health that may predispose crops to disease, such as nutrient deficiencies or toxicities. While soil health can influence the incidence of certain diseases, it does not provide direct insight into the likelihood of disease spread as effectively as weather factors. Pest populations are directly related to the spread of certain diseases, especially those that are vectored by insects or other organisms. Monitoring pest populations can help predict which diseases might emerge based on the presence or absence of those vectors, making it a valuable tool in disease forecasting. Field history, while providing context on previous disease occurrences, does not necessarily predict future outbreaks. The occurrence of disease in past crops may not indicate that similar conditions or pathogens will be present again. Additionally, changes in agricultural practices, crop varieties