1. plural of preemergence; the period or stage before a plant or organism emerges or breaks through the soil surface
Usage: commonly used in agriculture and horticulture; often used as a modifier (e.g., preemergence herbicide)
2. herbicides or treatments applied before seeds germinate and seedlings emerge from the soil
Usage: technical/agricultural term

Examples

• Farmers apply preemergences in spring to prevent weed seeds from sprouting.
• The preemergences were effective at controlling crabgrass before it appeared.
• Gardeners often use preemergences on their lawns to stop dandelions from emerging.
• Different preemergences work best at different soil temperatures.
• The timing of preemergences is critical for maximum effectiveness.