Degree-days are used in horticulture to

• A. Predict crop development and schedule labor or treatments
• B. Measure soil pH
• C. Estimate rainfall
• D. Determine pruning dates

Answer: (A)

Degree-days track accumulated warmth to forecast plant development. By adding up the daily heat above a base temperature, growers estimate when crops will reach key growth stages such as bud break, flowering, or fruit set. Knowing these timings lets you plan labor, irrigation, fertilization, and protective treatments so they align with the crop’s actual development rather than the calendar. This is why degree-days are used to predict crop development and schedule management activities.

They aren’t used to measure soil pH or estimate rainfall, which are soil chemistry and weather variables, respectively. Pruning dates can be guided by growth stage or calendar, but degree-days specifically target anticipating developmental milestones to time interventions.