Good crop management will be key to maximising output and profitability from sugar beet and fodder beet crops this season.
Both crops face several challenges – on top of a sugar beet price which is “not too exciting,” says Jim Nutting, technical manager for agronomy specialists ProCam. But agronomic tweaks will help improve margins, he adds.
“Potentially the biggest threat is virus yellows,” says Mr Nutting. “The forecast has put the risk as higher than last year – and with neonicotinoid seed treatment not available, the crop will be more exposed to the aphid-borne virus.”
Growers to be extra vigilant with beet crops planted after late-destroyed cover crops, or near to late-lifted beet crops, because both harbour overwintered aphids.
Size matters
“Another key consideration is crop size,” says Mr Nutting. “Before 12 leaves, beet is more susceptible to virus yellows. So later-drilled crops that are still small when aphids arrive are at greater risk.
“If the technique of drilling beet into sacrificial rows of spring barley is used, this can buy some time as aphids seem to prefer the barley. But the barley must be removed at 2-3 leaves to avoid it outcompeting the beet.
Chemically, Mr Nutting says he tends not to use pyrethroid aphicides because of resistance. But there are good, non-pyrethroid options, allowing varied modes of action, he adds.
“They’re not all approved in both sugar beet and fodder beet – and I save those that are kinder to beneficial organisms to when beneficials are about. So [my advice is to] seek guidance on which to use when.”
Frequency
The number of aphicide sprays in programmes will depend on aphid thresholds being reached, with lower thresholds in younger crops. By 16 leaves, plants should be pretty much immune to the virus, but that stage might not be reached until June.
“Also, aphicides usually need dedicated application timings and higher water volumes than herbicides, which is crucial for spray coverage as young beet plants are a small target,” says Mr Nutting.
Correct nutrition is also important for giving beet the best start and healthy growth. Macronutrient needs are well known, but growers should not neglect micronutrients and biostimulants.
“Beet tends to suffer from manganese deficiency. So I typically apply manganese and magnesium early. If boron wasn’t in the base fertiliser, it’s usually also needed. Then I feed with magnesium through the season.
“I also find beet responds well to a biostimulant. It helps to get the crop growing but also tends to improve it through the season. Zodiac is my benchmark – it contains seaweed extract and amino acids for reducing crop stress.
“Beet can get stressed by cold spells, herbicides or drought. So I often suggest three spring applications, then another with the first fungicide, typically late July, when crops can be coming back under stress.”
Disease
Besides mildew and rust, cercospora is an emerging risk to beet crops. A problem in Europe, there are concerns the UK has developed a strain adapted to our climate, he says, and concerns about fungicide resistance.
“Cercospora thrives in warm, humid conditions, including foggy weather or dews. Growers are advised to sign-up to the British Beet Research Organisation’s Cercospora Watch for text alerts on the disease.
“Fortunately, some fungicides active against powdery mildew and rust are also active on cercospora, but it’s important to choose the correct one and practice resistance management,” says Mr Nutting.