With more high temperatures anticipated, sugar beet growers are being advised not to leave the door open for disease threats to take hold.
The timing of fungicide intervention is highly strategic, says Professor Mark Stevens, head of scientific endeavour at BBRO. While initial applications are typically recommended from mid-July onwards, Mark stresses that different diseases peak at different times. Powdery mildew will be a concern this year. However, damp and warm conditions could prompt outbreaks of cercospora as well. “Powdery mildew is perhaps the first candidate but growers must also remain prepared for the possibility of cercospora, and later in the season, rust.”
Where growers are tackling uneven crops, it is the most forward plants that have the most yield potential. “Protecting those plants at the later growth stages helps to keep disease out and prevent further spread,” explains Mark.
Looking ahead, he reminds growers of the importance of timely applications: “Don’t let the door to disease open between applications. From our trials, spray intervals of 21-28 days tend to offer the best disease control, keeping the canopy healthy. I know it is a busy time of year on farm but if disease gets in, it becomes very difficult to stop.”
BASF business development manager, Paul Goddard says that it is very rare for one fungicide application to provide adequate defence, even for the earliest lifted crops.
Fungicides approved for use in sugar beet are limited. Given FRAC guidelines on the use of products containing QoI chemistry and the label restrictions of other solutions, Paul advises topping up a first application with Revystar at the T2 followed by Angle or Priori Gold. This approach is also fully FRAC compliant. “Revystar is a product that is perfectly balanced, offering broad and effective control from both active ingredients. They support one another with strong activity against all the major diseases – powdery mildew, cercospora, rust and ramularia,”
Don’t close the gate on beet crops too early, reminds Mark. “Remember beet can gain up to 40% yield potential from the 1st September onwards, so everything you can do to ensure that it is a healthy, photosynthesising crop is important.”
