This is a challenging year following a protracted lifting campaign and late drilling in some areas of the country. The dry spring has also caused uneven establishment and crops that are at vastly different growth stages, even within the same field.
This will mean taking a close look at crops field-by-field, to determine the order of priority for foliar disease control. Rust (Uromyces betae) will still be the main disease to watch for, but the recent high spring temperatures indicate an increased risk of powdery mildew (Erysiphe betae) this year.
In light of this season’s challenges, we have brought together some key advice to help you manage disease in your crop and protect your yield potential.
Aim to maintain a green crop canopy for as long as possible. Maximising green leaf area will help plants to continue growing and accumulating sugars into the autumn, before lifting begins. Crops that are growing well, with the best yield potential, should be the first priority for a robust fungicide programme. But even poorly performing crops will benefit from at least one fungicide spray to maintain their growth.
Regular crop walking is essential to identify early signs of infection. Rust is still the principal disease to watch out for, with the potential to reduce yields by up to 20%, but the risk of powdery mildew infection is higher this year and can cause up to 14% yield loss.
A robust fungicide programme is essential to prevent significant reductions in yield potential. Application timing is important, and should be determined by signs of disease in the crop or reports of it circulating locally, rather than calendar date.
The unusual spring weather this year means the risk of both rust and powdery mildew may come earlier than usual, but variations in plant size also need to be considered for spray timings.
Escolta(cyproconazole + trifloxystrobin) should be applied at the full rate in sufficient water volume to allow the spray to penetrate the whole canopy. In dense crops, higher water volumes should be used.
A follow up application of Escolta four weeks later increases the likelihood of maintaining green cover until autumn, and protecting yield potential.
Using fungicides to protect the canopy from disease also means that plants are better able to withstand the effects of drought. However, it is important not to apply any plant protection products to sugar beet crops that are already showing signs of wilting.
Apply fungicides during cooler periods or the day, either early or late, and as soon as disease is detected, to protect performance.
Use the appropriate water volume for the density of leaf canopy and a medium nozzle quality to ensure that the spray effectively penetrates the crop and provides protection to the whole leaf area.
The evidence demonstrating the benefits of Escolta in protecting yield potential is substantial.
Despite the variation in disease onset each season, the latest results from Bayer’s long-term fungicide trials support the recommendation to apply Escolta at the first signs of disease, and then again about four weeks later.
This provides the greatest yield protection and offers the biggest increase in yield, particularly in later-lifted crops.
Trials in 2019 showed crops that received two sprays of Escolta yielded 18t/ha more than untreated crops when lifted in October, while February-lifted crops yielded 22t/ha more than untreated. And while 2019 might have been an exceptional year, long-term trials still demonstrate a significant yield premium. Results from 10 years of trials show the average yield response from two applications of Escolta has been an extra 9.6t/ha compared with untreated crops.
Sugar beet is one of the crops most responsive to good agronomy. And within its agronomy, crop protection is a major contributor to yield and profit. We at Bayer are focused on providing solutions to all the crop protection issues you face in growing sugar beet, be it weed competition, pest damage or disease threats.
Weed control in sugar beet has always been a compromise between crop safety and being able to control weeds effectively.