Dayboro Pest & Disease Risk Calculator
Real-time pest and disease risk assessment for Dayboro gardens using live temperature, humidity, and rainfall data from our local weather station
Generic pest calendars tell you "watch for aphids in spring." That's not wrong, but it's not very helpful either. Aphid populations explode when temperatures sit between 15–25°C with moderate humidity — conditions that can happen in Dayboro from March through November depending on the year. This calculator checks what's actually happening right now and scores each pest threat accordingly.
Understanding Pest Pressure in the Dayboro Valley
Dayboro's subtropical position in the D'Aguilar Range foothills creates conditions that most garden pests find irresistible. Warm temperatures, reliable rainfall, and the valley's natural humidity trap combine to produce an environment where pest populations can build quickly. The same microclimate that makes Dayboro excellent for growing vegetables also makes it excellent for growing the things that eat them.
What makes pest management particularly tricky in the Dayboro valley is the speed at which conditions change. A dry spell suppresses fungal diseases but sends spider mite populations through the roof. A week of rain knocks back the mites but rolls out the red carpet for downy mildew and root rot. Understanding which pests thrive in which conditions is the difference between a productive garden and a frustrating one.
How Weather Drives Pest and Disease Risk
The calculator scores each pest on a scale of 0 to 100 using four weather factors, each weighted by its importance for that specific pest:
Temperature (0–30 points)
Every pest has an optimal temperature range. Aphids thrive at 15–25°C; spider mites prefer it hotter at 25–35°C. The score is highest when the current temperature sits in the middle of the pest's preferred range, and scales down toward the edges. Outside the range, the temperature contribution drops to zero.
Humidity (0–25 points)
Fungal diseases like powdery mildew and downy mildew are directly driven by humidity. Insect pests have preferences too — spider mites hate humid conditions, while snails and slugs love them. Each pest's humidity range is scored on a sliding scale.
Leaf Wetness (0–15 points)
Our station's leaf wetness sensor measures the percentage of moisture on leaf surfaces. Values above 50% significantly increase the risk of fungal diseases and create favourable conditions for slug and snail activity. Dry leaf surfaces reduce disease transmission.
Recent Rainfall (0–15 points)
Rain in the last 24–48 hours affects different pests differently. Heavy rain (above 10mm) boosts slug, snail, and fungal disease risk but suppresses dry-weather pests like spider mites and thrips. Light or no rain favours the dry-weather pests.
Sustained Conditions Bonus (0–15 points)
When favourable conditions persist for 3 or more days, pest populations have time to build. The calculator checks recent rainfall trends and temperature stability to award a bonus for sustained conditions. This explains why a single warm, humid day is less dangerous than a week of them.
Pest Season Calendar — Dayboro Valley
| Pest / Disease | Peak Season | Key Driver | Primary Targets |
|---|---|---|---|
| Aphids | Mar – Nov | Mild temps (15–25°C) | Tomato, Capsicum, Lettuce |
| Whiteflies | Sep – Apr | Warm temps (20–30°C) | Tomato, Cucumber, Beans |
| Snails & Slugs | Year-round (peaks in wet) | High humidity + rain | Lettuce, Cabbage, Strawberry |
| Spider Mites | Oct – Mar | Hot + dry (25–35°C) | Tomato, Beans, Cucumber |
| Caterpillars | Sep – May | Warm temps (18–30°C) | Brassicas, Lettuce |
| Thrips | Sep – Apr | Warm + dry (20–30°C) | Onion, Garlic, Beans |
| Fruit Fly | Oct – May | Warm + humid (20–32°C) | Tomato, Capsicum, Zucchini |
| Powdery Mildew | Mar – Nov | Moderate humidity (60–80%) | Zucchini, Pumpkin, Cucumber |
| Downy Mildew | Apr – Sep | Cool + wet (10–22°C) | Lettuce, Spinach, Onion |
| Late Blight | May – Aug | Cool + very wet (12–22°C) | Tomato, Potato |
| Root Rot | Year-round (peaks in wet) | Waterlogged soil | Beans, Peas, Capsicum |
| Rust | Mar – Oct | Mild + humid (15–25°C) | Beans, Garlic, Silverbeet |