The green, yellow and red bands on your spore concentration graphs are called traffic light thresholds. They give you a fixed visual reference for whether a spore level is low, moderate or high — without them, the graph's scale adjusts automatically to your data, which can make a small spike look just as dramatic as a large one.
Green - low or background levels
Yellow - elevated, worth monitoring more closely
Red - high levels; infection risk is elevated if the weather is also favourable
How We Set The Thresholds
We set thresholds for each disease using the best evidence available, in this order:
Published research - we look for studies linking airborne spore concentrations of that pathogen to disease outbreaks, ideally on the same crop. If that's not available, we use the closest match (the same pathogen on a related crop, or a related pathogen on the same crop)
Our own BioScout data - where we have enough history, we compare spore readings from sites where disease was confirmed against sites where it wasn't, to sense-check the literature against what our units actually detect
Expert judgement - we weigh the two sources above and make a considered call. Where there's no usable data at all, we start from a conservative baseline and refine it from there
Good To Know
Thresholds are a guide, not a clinically validated limit. Field scouting, crop growth stage and weather conditions should always factor into your decision-making alongside them. Every property is different, so if your own field observations consistently disagree with what the graph is showing, let us know - your thresholds can be adjusted in consultation with our science team.
Need help?
If you'd like your thresholds reviewed for your specific crop or site, contact the BioScout support team from the dashboard — go to Contact Support and fill in the form, and we'll get back to you.