SCEPTREplus: Bush fruit

Control of blackcurrant gall mite

• Crop: Blackcurrant
• Target: Gall mite (Cecidophyopsis ribis)
• Period: Feb 2018-March 2019, Feb 2019 - March 2020

Take home message

• The duration of gall mite migration may vary depending on plantation and cultivar
• The industry standard of two early sprays of sulphur provided good control of gall mite on the variety Ben Vane
• These products require further evaluation

Trial summary

Sulphur is still the most effective method of gall mite control currently available. But there are products on the horizon that will reduce the industry’s reliance on this single product. The behaviour of the blackcurrant gall mite has changed and is no longer accurately predicted by the emergence model. Work is required urgently to provide the data to realign the model with what is actually happening in the real world.

• Crop group: Blackcurrant, Ribes, bush fruit
• Target: Broadleaf weeds and grasses, black nightshade, field bindweed,
• Period: Apr-Oct 2018, Apr-Dec 2019

The limited range of contact herbicides currently available to blackcurrant growers has left gaps in the weed control spectrum.

The recent withdrawal of diquat from the market has further reduced options available. Field bindweed is not controlled well by herbicide programmes used in blackcurrants and hand-weeding is the only, expensive, option.

Residual screening trials

AHDB 9975, AHDB 9898 or AHDB 9900 could give growers alternative options for residual weed control and improve control of black nightshade.

Contact herbicides

An approval for AHDB 9866 could offer an alternative to Roundup PowerMax for control of bindweed and general broad leaved weeds.

Contact herbicides - follow up trial

AHDB9866 and AHDB9897 gave the best general weed control in the plots during the trial, with AHDB9866 performing best against field bind weed. These products should be considered for EAMU applications based on the efficacy and crop safety during the trial.

Preventing spotted wing drosophila laying eggs

• Crops: Blueberry and blackberry, but relevant to soft fruit, stone fruit and grapes
• Target: Spotted wing drosophila (Drosophila suzukii)
• Period: January - March 2018

Take home message

AHDB9931 and Urtica showed greatest potential to reduce the emergence of spotted wing drosophila (SWD).

Further testing is required on different crops to validate the results

Trial summary

The aim of the project was to test whether products can act as egg laying deterrents for SWD or reduce their emergence.

Seven different chemical treatments were tested in a laboratory.

A further study on the most promising treatments proved inconclusive.

• Crops: A range of crops (Strawberry, cherry, raspberry, blackberry, apple, pear, blackcurrant, cucumber, celery, potato, tomato)
• Target: Capsid bugs
• Period: Sept 2018 – Jan 2019

Management of these pests currently relies on application of broad-spectrum insecticides. These can be effective at killing capsids, but also reduces numbers of the naturally-occurring and released natural enemies to control other pests.

This review aims to identify capsid control options that may form basis of further research including efficacy trials.

Conclusions

• Insecticides with more selective activity against sap-feeding pests, and lower impact on beneficial natural enemies (e.g. sulfoxaflor and flonicamid) have become preferred interventions for capsids in Australia and the USA
• Novel insecticides with alternative modes of action are available for testing against capsid pests
• Improved formulation of insecticides may be possible. This may be achieved by mixing with salt or enclosing them in attractant-coated microcapsules
• The entomopathogenic fungi Beauveria bassiana and Metarhizium brunneum are available as commercial formulations and should also be considered as candidates for inclusion in efficacy testing.
• Particular weeds (e.g. nettles) are assumed to be linked with capsids and control of these is recommended
• More information is needed on the role played by natural enemies
• Semiochemical-based approaches (including push-pull strategies and pheromone based monitoring traps) have been developed for capsids as part of previous AHDB-funded work and have potential for further refinement