What It Tells You
A pest forecast says when the weather has favoured a pest or a disease on a field, before symptoms show. Aphids develop with temperature, so the BYDV count runs on degree-days. Septoria, yellow rust and brown rust need hours of leaf wetness inside each pathogen’s temperature range. The Foliar Disease Risk model gives each wheat field a pressure level per disease during the latent period, when nothing is visible. Fusarium head blight infects at flowering. The Fusarium Head Blight Risk model gives a probability for the week around anthesis. A forecast describes conditions. It says infection was favoured. It does not say the crop has the disease.How It Works
Each forecast runs a degree-day or published risk model. BYDV sums degree-days above 3 °C from emergence. Foliar disease accumulates wet hours at infective temperatures from a leaf-wetness sensor on the field, scaled by the variety’s susceptibility rating. FHB reproduces a published logistic regression on hours of warmth, humidity and rain around anthesis. Each model writes a row per field per day. The field card shows the result, or the reason when the model cannot answer.
Degree-days build up on the field card and each disease gets a pressure level.