Vine weevil in soft fruit: Cultural control

Overview

Vine weevil populations build up on infested plants that have been kept on the farm for more than one season. There are a range of cultural control measures that can be used both to reduce sources of the pest and to limit its spread if a crop becomes infested. Paying close attention to farm hygiene can help to reduce the sources not only of vine weevil but also of other pests and diseases.

Before planting a new crop

• Aim to control vine weevil in older crops (see Biological control sections) before any younger neighbouring plantations become infested.
• When establishing a new plantation, where possible find a site isolated from vine weevil-infested crops.
• When planting at a site directly following a crop known to be infested with vine weevil, consider sterilising the site prior to re-planting and pay particular attention to the removal of all trash and debris which could harbour the pest.
• If vine weevil larvae are present in the remains of a previous soil-grown crop, do not replant soon after the previous crop.
• Plant the following year if possible and cultivate the soil regularly to reduce the root system remaining as a food source for larvae. Cultivation will also help to bring any old plant material to the surface in good time before planting the new crop, to expose the larvae to predators such as birds.
• Remove any container-grown plants from a previous crop that may harbour vine weevil and all old containers (bags, pots and troughs) and crop debris.
• Dispose of these materials promptly.
• Old plants and substrate can be chopped and spread onto arable land well away from soft fruit crops.
• Old containers should preferably be sent for recycling or alternatively to landfill.
• Check a sample of new plants in pots or trays before planting for the presence of vine weevil larvae by knocking them out and searching through the growing media.
• Also check for any adult vine weevil leaf notching or plants showing symptoms of larval damage to roots such as stunting, wilting or yellow or red leaf discolouration.
• Ascertain what control measures have been used on the new plants for vine weevil management. Ideally pot or tray plants will have been drenched with nematodes by the propagator.

During crop production

• In AHDB Horticulture funded project CP 111 ‘A review of vine weevil knowledge in order to design best-practice IPM protocols suitable for implementation in UK horticulture’, removal of polythene or ground-cover matting mulches on strawberry crops grown on soil beds was reported by growers to considerably reduce severe infestations.
• However, this is often impractical and the mulches are important for maintaining weed and runner control.
• Tabletop strawberries can be less susceptible to vine weevil, although adults can climb up tabletop supports.
• The use of barrier glue on the table supports helps to prevent this.
• Control weeds at the edges of mulches and around field margins, particularly those that can potentially harbour vine weevil, such as dandelion, dock, knotweeds, mallow, orache, plantain and rosebay willowherb.
• Keep punnets and trays off the ground during picking in affected crops and be vigilant for adults falling or crawling into punnets.

Original author/s

Jude Bennison, Janet Allen & John Atwood, ADAS

Tom Pope, Harper Adams University