Disposal of spotted wing drosophila fruit waste

There are a number of methods of disposing of Spotted wing drosophila (SWD) fruit waste, although not all are economically viable for every grower. Discover the range of options available to you.

This information was last updated in 2016.

Disposing of treated fruit waste

Following treatment in sealed pallet bins, although the number of emerging SWD will be eliminated or reduced to a very low level, the waste remains attractive to egg-laying SWD adult females and retains the potential to rear a complete SWD life cycle.

The treated waste must therefore be disposed of so that it is no longer attractive to breeding SWD.

Treated fruit waste should be spread onto bare soil and then incorporated to a depth of 20cm with a tractor-mounted rotavator.

Treated areas

The waste then rapidly degrades in the soil and, to date, no SWD have been observed in the treated areas of fields.

The maximum amount of organic waste that can be applied to land is restricted by the EU Nitrates Directive in Nitrate Vulnerable Zones (NVZs) to an equivalent of 250kg N/ha.

Fruit wastes contain about 0.2% N fresh weight, allowing up to 125 tonnes of fruit waste to be applied per hectare each season.

This must not be done during the ‘closed season’ for land-spreading (October to March) and a record must be kept of the amount of waste applied.

Other methods

• Other disposal methods for treated fruit waste include mixing with organic wastes in a concreted bay.
• The quantity of fruit waste in the mix should not exceed 10% w/w.
• Treated fruit waste can also be covered with a 20cm layer of soil or spent grow bag substrate and composted until it is no longer attractive to SWD (this duration has not been established).
• Before land spreading and incorporation, the quantity of stored waste should not exceed 50 tonnes/ha.
• Any run-off should be collected and not allowed to contaminate water courses.
• If there are large-scale composting or anaerobic digestion facilities in the vicinity of fruit production, they may accept fruit waste.
• The economics of these disposal routes will depend on the value or gate-fee for the fruit, and on the distance to the processing facility.
• However, before dispatch, secure storage of the waste must be considered so that it is not attractive to SWD and does not create an SWD risk.

Authors

Ralph Noble and Andreja Dobrovin-Pennington