Which phrase best defines 'plant-regulating materials' as used for a golf course?

• A. Fertilizers, pesticides, or defoliants applied or intended for application to a golf course.
• B. The tools used to apply pesticides.
• C. The irrigation scheduling.
• D. The grasses used on the greens.

Answer: (A)

Plant-regulating materials are substances used to influence how turf grows or stays healthy on a golf course. This includes nutrients and chemicals that are applied to the grass, such as fertilizers (which feed the grass), pesticides (which protect the grass from pests), and defoliants (which remove leaves or alter growth). The phrase “applied or intended for application to a golf course” covers both products already being used and those planned for use, which is why fertilizers, pesticides, or defoliants fit this definition best. Tools, scheduling, or plant species themselves aren’t materials that regulate growth, so they don’t match the term.