Sugar beet growers face a higher risk of virus yellows this season following a slow start to drilling across key regions.
Many crops have only recently gone in the ground – much later than last year when growers had prepared land by early March. Much heavier land remains untouched, with the delay increasing risk.
Rothamsted Research scientists suggest aphid migration could begin around 22 April – with up to 62% of eastern region beet crops infected without control measures from a 30 March drill date, increasing to 77% infection for crops drilled from 15 April.
The risk mirrors recent high-pressure seasons, sauy UPL head of technical services Stuart Jackson. “Virus yellows risk is comparable to 2022 and 2023 in the eastern region, with one important difference.”
“In those years, the risk was mitigated by over 50% of the crop being treated with neonicotinoid seed dressings, something that is not an option this season.”
Establishment first
Mr Jackson urges growers not to force drilling in poor conditions, despite the elevated risk. Drilling into poor seedbeds risks an uneven crop, reduced plant populations and higher harvesting losses.
“Those types of gappy, uneven beet crops ultimately end up with much higher levels of harvester losses,” says. Mr Jackson. “Don’t rush drilling. Wait for better conditions. Drilling later in favourable conditions is better than going too early.”
Growers can use higher soil moisture this spring to improve pre-emergence herbicide performance. Most fields will benefit. Black soils remain the main exception because residual activity performs poorly there.
Growers should use field history to guide decisions. Fields with fat hen will benefit from metamitron. Heavier infestations may require ethofumesate in mixes to improve control and maintain flexibility later in the programme.
Weed size
In Conviso Smart systems, growers can apply early herbicides to control weed size before applying Conviso One.
This approach also helps manage resistance in species such as poppy, chickweed and mayweed, explains Mr Jackson, who says grassweed control remains a concern.
Trials by UPL show that poor timing and application often cause performance issues with clethodim. Formulation differences can also affect efficacy, he adds.
Small differences in control can create large problems. “Just a few percent difference in control of a weed like blackgrass can result in much higher weed seed return.”
What growers should do now:
Sugar beet growers face a narrow window this spring. Decisions in the next few weeks will shape crop performance and margins.
• Prioritise seedbed quality
Avoid drilling into poor conditions. Compaction, smearing and capping reduce establishment and increase variability across fields. Even crops improve management and harvesting.
Aphids will likely begin migrating from late April. Later-drilled crops will face greater exposure when plants remain small and vulnerable. Growers should monitor crops closely and act when thresholds are reached.
With moist soils, pre-emergence herbicides should perform well this season. Tailor programmes to field history. Residual activity reduces early weed competition and eases pressure on post-emergence applications.
• Manage resistance
In Conviso systems, early intervention can help control weed size and limit resistance risks. In conventional crops, growers should focus on timing and product choice, especially for grassweeds.
Finally, focus on margins. With high prices for fuel, it’s important to remember that very pass must deliver value – and drive better returns.