Massachusetts Pesticide License Practice Exam

What is one of the outcomes of using defoliants?

1. Reduction of pest population

2. Improved pest resistance

3. Premature drop of leaves for easier harvesting

4. Increased growth rates of crops

The correct answer is: Premature drop of leaves for easier harvesting

Using defoliants leads to the premature drop of leaves, which facilitates easier harvesting of crops. Defoliants are chemical agents that cause the leaves to fall off the plant by disrupting normal physiological processes. This can be particularly beneficial in agricultural practices where timely harvesting is crucial. For example, in cotton production, a defoliant may be applied to promote synchronized leaf drop, allowing harvesters to collect bolls more efficiently and improve the overall quality of the cotton. The other options pertain to effects that are not typically associated with defoliants. Reducing pest populations is usually achieved through insecticides or biological control methods rather than defoliants. Improved pest resistance often results from breeding practices or the use of resistant varieties rather than chemical applications. Increased growth rates of crops are generally influenced by factors such as nutrients, water, and sunlight but not directly by the application of defoliants, which primarily serve to manage the timing of leaf drop for easier harvesting rather than promote growth.