Disease Forecasting Model Calculator

Predict plant disease infection risk from weather conditions, host susceptibility, and inoculum pressure using DSV-based forecasting.

Average temperature (°F)

Leaf wetness duration (hours)

Relative humidity (%)

Host susceptibility (1-10)

Inoculum pressure (1-10)

Consecutive favorable days

Tab to move between fields

Daily infection risk (0-100)

74.3

Risk rating (1-5)

Temperature favorability (0-1)0.9

Moisture favorability (0-1)0.75

Disease Severity Value (DSV/day)3

Cumulative DSV9

Days to spray threshold6

How to Use This Calculator

Enter Average temperature (°F), Leaf wetness duration (hours), and Relative humidity (%).
Set Host susceptibility (1-10), Inoculum pressure (1-10), and Consecutive favorable days.
Review Daily infection risk (0-100) and Risk rating (1-5).
Use Temperature favorability (0-1) and Moisture favorability (0-1) to inform your decision.

How the result changes with Average temperature (°F)

Average temperature (°F): Average daily temperature. Most foliar pathogens favor 60-80°F.
Leaf wetness duration (hours): Hours per day leaves remain wet from dew, rain, or irrigation. Key infection driver.
Relative humidity (%): Average relative humidity. >80% enhances spore germination.
Host susceptibility (1-10): Cultivar susceptibility rating. 1 = highly resistant, 10 = highly susceptible.
Inoculum pressure (1-10): Pathogen inoculum level based on disease history, neighboring fields, residue. 1 = very low, 10 = extreme.
Consecutive favorable days: Number of consecutive days with similar weather conditions (for cumulative DSV).

Daily infection risk (0-100): Composite daily disease infection risk index.
Risk rating (1-5): 1 = Very Low, 2 = Low, 3 = Moderate, 4 = High, 5 = Very High.
Temperature favorability (0-1): How favorable the temperature is for pathogen development.
Moisture favorability (0-1): Combined leaf wetness and humidity favorability for infection.
Disease Severity Value (DSV/day): Daily DSV accumulation (0-4 scale, similar to Tom-Cast system).
Cumulative DSV: Total accumulated DSV over consecutive favorable days.
Days to spray threshold: Estimated days until cumulative DSV reaches the spray threshold (18 DSV) at current rate.

Identify Input Parameters
4 parameters
Average temperature (°F) = 68, Leaf wetness duration (hours) = 12, Relative humidity (%) = 85, Host susceptibility (1-10) = 6 = 6 input(s) provided
Calculate Daily infection risk
Daily infection risk = min(100, max(0, dailyRisk))
74.3 = 74.3
Calculate Risk rating
4 = 4
Calculate Temperature favorability
Temperature favorability
0.902 = 0.902
Calculate Moisture favorability
0.75 = 0.75