Root rots Root and stem rotting can be an issue during the winter months in cool and damp conditions. Some crops are prone to Pythium, Phytophthora and Fusarium so keep them on the drier side this winter. Drench affected plants, within their irrigation regime, with Fenomenal, Previcur Energy (EAMU 2011-1557) or Subdue depending on temperatures. Do not apply if frost is predicted before, during or after applications.
Hot water treatment Treat stock plant material this winter for leaf and stem eelworms, Pythium, Phytophthora and rusts on affected ornamental crops. With Vydate 10G no longer available for use, Movento (EAMU 2011-1987) is now currently the only effective insecticide but should only be used in the growing season because of its systemic activity. AHDB fact sheet 10/13 provides details of tank construction.
Servicing Recalibrate and service spray equipment including pressure gauges, measuring scales, jugs and syringes. Check for worn parts, leaky hoses and blocked nozzles, and replace kit where measurement graduations are no longer legible. Use the National Sprayer Testing Service (see www.nsts.org.uk) to test older equipment under the Sustainable Use Directive.
Winter weeds Products including Flexidor and Butisan S can be applied in the dormant season. For bittercress, willowherb, pearlwort and mouse-ear chickweed, use Chikara, Devrinol (EAMUs required), selected products containing pendimethalin, Shark (EAMUs required), Sumimax (EAMU 2008-2881) or Venzar Flowable. Roundup will control pearlwort, while Chikara and Sumimax work well on groundsel. Check crop tolerance by looking through AHDB projects HNS 111, 132, 139a, 155, 166 and 175.
Water stress Clear, sunny days and frozen pots on evergreen crops can encourage drought conditions when water is unavailable in the compost. Apply anti-transpirant products such as Wiltpruf S600 to reduce transpiration levels during such weather conditions.
Winter jobs Get under cover in poor weather and start tidying up climbing plants. Get them caned and tied in ready for the coming season.
Post-holiday checks Routinely check all glasshouses and polytunnels for any damage and budget accordingly.
Fogging Cold-fog in protected structures to keep water sitting on foliage and bare stems to a minimum. Apply in the morning to allow foliage time to dry off during the day. Do not spray frozen plants. Where necessary, use contact-acting products at this time of year to ensure more effective control.
John Adlam, managing director, Dove Associates