Which factors influence how quickly endothall works after application?

• A. pH, salinity, and sunlight
• B. density and size of plants; water movement; water temperature
• C. color of water and odor
• D. time of day of application and wind direction

Answer: (B)

Endothall’s speed of action depends on how well the chemical can contact and be taken up by the plant tissue in the water, which is largely determined by plant density and size, how the water moves, and the water temperature. If plants are dense or large, there’s more tissue to saturate, so the visible effects may take longer to appear because more material has to be contacted and absorbed. Water movement matters because currents and mixing influence how long the chemical stays near surfaces and how evenly it distributes; too much movement can dilute or remove the compound before it fully contacts all target tissues, while enough mixing helps the treatment reach more surfaces. Water temperature affects chemical activity and plant uptake: warmer water generally speeds up uptake and metabolic processes, leading to quicker visible results, whereas cooler water slows things down. Other factors like pH, salinity, sunlight, color or odor, or the time of day and wind direction can influence other aspects of application or chemical stability, but they don’t determine the rapidity of endothall’s action as directly as the three main factors above.