Thinking ‘ABCD’ for integrated aphid management

In order to manage virus yellows in the future and reduce dependence on man-made pesticides, BBRO launched a new strategy (partly funded by Defra) in spring 2022 to investigate how growers can manage aphids in a more natural fashion. The research will be investigating four major techniques.

Each year, BBRO delivers an aphid monitoring survey during the spring to guide growers on local aphid levels and progression of the migration. This acts as a guide for growers to monitor their crops and see if their elds have reached the population threshold for control (e.g. one green wingless aphid per four plants up to the 12-leaf stage) at which they are advised to treat the crop with a foliar aphicide.

As of 2022, two aphicides are registered in sugar beet; onicamid, sold as Teppeki by Belchim Crop Protection or A nto by Syngenta; and acetamaprid, a neonicotinoid, marketed as InSyst by Certis. Both currently o er e ective control of aphids. However, they require broad-acre spraying and these can potentially have indirect impacts on natural predators of aphids also on the crop. Myzus persicae is also known to develop resistance to insecticides and therefore these may not o er complete or long-term aphid management into the future. Considering the limitations of relying on chemical seed treatments or broad-acre sprays, and the drawbacks these pose to the environment, BBRO is keen to investigate commercially adaptable IPM strategies for aphid control in future sugar beet crops. This latest research is proposed as four individual work packages: Attractants, Bene cials, Camou age, and Deterrents, all of which is being overseen by BBRO’s Dr Alistair Wright (pictured).

Attractants

This is the use of alternative hosts species to pull migrating winged aphids away from sugar beet. It is established that the UK’s main aphid threat, Myzus persicae, the peach-potato aphid, has a preference for brassicas or potatoes instead of sugar beet. BBRO will soon be looking at whether growers can integrate strips of these alternative species into sugar beet species to pull aphids away from, and stop them migrating through, sugar beet elds. BBRO has e ectively used strips of oilseed rape and radish within its virus yellows varietal tolerance trials since 2019. However, the organisation needs to see how this can be done commercially and economically. , the peach-potato away from the crop. These trials will start in controlled, glasshouse conditions to screen a wide range of products before grower events, the organisation intends to keep growers up-to-date with the

Bene cials

These investigate how growers can encourage natural populations of bene cial insects into sugar beet crops by o ering suitable habitats, such as wild ower strips, in and around sugar

BBRO hopes to nd out if eld dyes deter aphids from landing on the sugar beet and, if they do, which colours prove most e ective.

beet elds. BBRO is also undertaking evaluations of deploying commercially available bene cial insect products, widely used in horticulture, outdoors and on a broad-acre scale.

Camou age

Reducing the plant-soil contrast is a known method to prevent aphids from colonising plants. Manipulating this contrast can camou age crops in plain sight from the aphids and BBRO is looking at two distinct methods to achieve this: • Cereal camo-cropping – Cereal crops are widely used to prevent wind blow damage to sugar beet when it is immature. In 2020, during the last major VY epidemic, it was widely seen that crops that were protected with a cereal (often barley) showed reduced virus symptoms.

This year BBRO ran a camo-cropping campaign to encourage growers to join in and help the team work out if this can be a viable option for limiting aphid pressure. BBRO will conduct assessments on camo-cropped elds in the autumn to see if this o ers a viable option. • Field dyes – Introducing a competitive species alongside the sugar beet can lead to signi cant competition for resources and yield loss. Therefore, BBRO is also looking at how it can reduce the plant-soil contrast in any other ways. BBRO has been trialling fabric dyes to do this and will continue looking at any other product which can be applied to disguise the sugar beet. These dyes have been applied to trial plots ahead of the expected migration of aphids into crops and any impact on yield and reduction in VY symptoms will be monitored in autumn 2022.

Deterrents and repellents

BBRO’s nal aspect is looking at using plantbased essentials oils to see if these can be applied to sugar beet to repel winged aphids away from the crop. These trials will start in controlled, glasshouse conditions to screen a wide range of products before moving any possible candidates onto broad-acre investigations in future years. Using the BBRO website, podcasts, British Sugar communications and grower events, the organisation intends to keep growers up-to-date with the ndings to ultimately produce a practicable and