The challenge: Basal rot in onions, caused by Fusarium oxysporum f.sp. cepae (FOC), is a major constraint to onion production in the UK, with losses estimated at £11M per annum. FOC produces long-lived spores, and hence control is difficult and currently relies on soil sterilisation, fungicide drenches or seed treatments. However, the availability and use of some of the chemical methods are becoming increasingly restricted.
The study: FungiAlert worked with a leading onion bulb breeder, and with one of the UK’s largest agronomy companies, to help understand the use case of FungiAlert’s SporSenZ in detecting FOC in both onion seed production tunnels and in onion fields. Where positive identification of FOC was detected by the sensors, the nearby onions were inspected for disease.
✔ The SporSenZ screen detected high populations of FOC in onion seed tunnels (severe disease issues reported). Visual inspection of nearby onions confirmed FOC symptoms.
✔ In another seed tunnel (minor disease issues reported), FOC was detected alongside a natural occurring microorganism. Research highlighted that this microorganism is being used as a bio-control product against other plant pathogens, indicating the potential of this microorganism to reduce the disease pressure of Fusarium basal rot.
✔ At the time of testing, FOC was not detected in the field environment (disease issues not reported), indicating a healthy field.
✔ FungiAlert’s SporSenZ screen results correlated well with disease symptoms observed in the onion crop.
✔ FungiAlert’s SporSenZ screen is therefore a very useful tool for the detection of FOC in onion fields.
✔ Importantly, this study uncovered a potential bio-control product that could be used against FOC.
Future opportunities: FungiAlert are currently working with growers to help them identify high or low risk for FOC before planting, and to monitor the emergence of FOC through the growing season.