|Collaborators:||East Malling Research, Scottish Crops Research Institute, ADAS, Central Science Laboratory K G Fruits Ltd, Berry World, Summer Fruit, Marks & Spencer, Waitrose, AgriSense, Horticultural Development Council, East Malling Trust, East Malling Ltd, Bayer Crop Sciences, LEAF, Place UK, The Worshipful Company of Fruiterers, Assured Produce, Co op|
|NRI Project Leader:||David Hall|
Raspberries are very susceptible to botrytis, mildew, raspberry beetle, cane midge and aphids. Currently, pesticides are relied on for control and are applied close to harvest. Intensive use of pesticides, including the organo-phosphorus (OP) chlorpyrifos, which is used to control raspberry beetle and cane midge, is undesirable and unsustainable. Raspberry aphids, and the viruses they spread are becoming more important with the increase in aphids able to overcome the natural plant resistance. Botrytis is the major cause of post-harvest fruit rotting and has caused serious yield losses. Poor shelf-life reduces repeat buying. Retail surveillance has shown that >50% of UK produced fruit has fungicide and 22% have chlorpyrifos residues. The future registration of chlorpyrifos on raspberry beyond 2008 is in doubt. Screening trials by East Malling Research have so far failed to identify any alternative insecticide with significant activity for cane midge control, though many different materials of a wide range of types have been tested. Loss of chlorpyrifos would have serious adverse consequences for the UK raspberry industry as there is no alternative control measure for the midge. Raspberries are susceptible to rain and, to meet the requirements of major multiple retailers, the crop has to be grown under protection. Initial observations indicate increased risk of mildew in protected crops. Plant protection methods have not been adapted for this new growing environment, which provides opportunities to reduce reliance on pesticides. There is strong market demand, led by consumer expectations, to reduce, or ideally to eliminate, the occurrence of residues.
Botrytis: The dynamics of infection of leaves and the progression into canes which gives rise to the overwintering sources, the suppression of inoculum production and the effects of tunnel management, de-leafing and spawn control on microclimate, and in turn on botrytis, will be studied. Effects of fungicide timing and other practices on visible and latent botrytis will be determined with the objective of devising programmes that provide effective control and minimal residue risk.
Raspberry beetle and cane midge: The chemical ecology of these pests will be studied to identify new (midge) and optimise identified (beetle) attractants. Pest monitoring, "lure and kill" and "mass trapping" approaches will then be developed and evaluated for protected raspberry.
Mildew: The main source(s) of primary inoculum and the effects of canopy management, environmental management, and novel fungicides and alternative agents, on disease development will be studied, enabling development of sustainable disease management strategies.
Aphids: Field experiments will be conducted to optimise control by early or late season sprays of aphicides. Use of biological agents will be investigated.
Integrated system: In the final two years, an Integrated Pest and Disease Management programme combining these component methods will be developed, evaluated and optimised, focusing on the interactions of components, effects on other pests, disease and beneficials and the incidence of pesticide residues. An economic assessment and a growers' guideline will be produced.
The NRI component of this projects concerned with development of the sex pheromone for monitoring and control of raspberry cane midge. The pheromone was identified in previous work and was made available to growers at the beginning of 2006. Results of two seasons of monitoring are now being analysed. Trials of mass trapping and lure-and-kill approaches were carried out in England and Scotland during 2006 and 2007.