Sugar beet growers who made two summer fungicide applications appear likely to be rewarded with healthier plants taking full advantage of late sunshine and moisture.

Rust levels had increased dramatically in the recent wet and warm conditions, according to Syngenta’s technical manager Beth Hall. “Untreated crops are showing 100% infection with a rapid loss of leaf area, when there is still significant scope for further root bulking and increased sugar content during the autumn period.”

But crops treated with a single Spyrale (fenpropidin + difenoconazole) application in July, or, even more dramatically, two applications in July and August, were looking very healthy in independent trials, she said.

“A few rust lesions are beginning to appear in the single spray plots, but the crops treated twice are looking incredibly healthy with little or no infection.

“With this extension of the plant’s photosynthetic capacity there is the potential to hold off lifting and really boost the sugar content and yields from late sunshine.”

If leaves were healthy beet can go on adding yields right through the autumn, British Sugar agronomist Robin Limb said. “Crops can put on an additional 25% of adjusted yield from mid-September, with sugar content increasing by 0.2-0.4% a week through to November.”

That could be important after the dry summer limited growth.

Some growers, however, may need to start lifting to fulfil delivery schedules, get following crops drilled or avoid the risk of late harvest in wet soils, Mr Limb recognised.

But wherever possible he urged them to lift as close to possible to delivery into the factory. “There is a real chance to maximise yield in the field and minimise respiration losses in the clamp, which will both help to increase returns.”