Weed control Control weed growth on cleared container beds with a tank mix of Harvest and Ronstar Liquid. This product combination will burn off any weeds present and prevent re-emergence in the spring.
Disease watch Changeable weather means an increased risk of Botrytis, downy mildew and root rot infections. Monitor water applications and crops with a lot of foliage in tunnels and glasshouses. Between 10-20 degsC and a humidity of 100 per cent, Botrytis growth is irreversible after three hours. With automatic watering, alter the sequence by watering susceptible species early in the morning rather than at night. The foliage will dry out in the morning rather than staying wet all night. Aim to have the leaf surface dry at least once every 24 hours.
Western flower thrip Remember to keep applying Amblyseius cucumeris through the winter months on crops in frost-free structures. These predators are not very active but you should find a lower overwintering thrip population that will reduce early-season infestations.
Aphids and whitefly These pests are still active in tunnels and glasshouses. Clean up with sprays of contact-action products such as Aphox, Majestik or SB Plant Invigorator. If biological control applications have finished, also consider Decis or Hallmark WZT (EoA 2008-2944).
Chemical stores Check through your chemical store, update stock lists and make sure that you have all the older products at the front of the shelf. Check MAPP numbers at www.pesticides.gov.uk. Buy only what you need for a few months and re-order as required to avoid having large quantities of pesticides that can go out of date quickly. See Health & Safety Executive leaflet AIS16 (or SR24 for smaller stores) for good store practice.
Plums Avoiding stem damage at lifting, which can occur if machinery struggles in the wet, will help to reduce the risk of stem canker infections.
John Adlam, Managing director, Dove Associates