Horse chestnut leaf miner: Many horse chestnuts are infested with leaf miner at the moment. If you have specimen trees to protect there is a specific off-label approval (SOLA 0298/2008) that details the use of Admire as a systemic control applied as a drench.
Windbreaks: If living windbreaks are trimmed during October make sure that the trimmings are removed and burned as they can be a source of both pest and disease to the crops beside them.
Botrytis: Make sure the ventilation fans are all running now in tunnels and glasshouses; this is one of the most important times for them to be fully operational. Open the doors of polythene tunnels on all the days when the wind and temperature allow. This will reduce the incidence of Botrytis and ensure adequate air changes within a closed tunnel. Applications of Frupica SC, Rovral WP or Amistar need to have adequate wetting agent added to get good penetration. Note that Rovral WP loses approval in December 2008.
Leatherjackets: Craneflies' eggs are now hatching. The resultant leatherjackets often cause damage to outdoor conifer and shrub liners. Drench with chlorpyrifos, Admire or Intercept 70 WG.
Mites: Now is the time to apply Apollo 50 SC to outdoor crops of trees and shrubs with known red spider mite problems. This will reduce the over-wintering egg population. Include Aster and Picea glauca var. albertiana 'Conica' in the programme. On warm days it is possible to see rust mites on ash and Malus buds as they scurry about. Spray with Gyro/Talstar, chlorpyrifos or Sequel to reduce the over-wintering population.
Phoma: This common fungus is still quite active on a range of nursery stock subjects. It is most commonly identified as a blackening of the stems part way down a shoot and the wilting of that shoot to the tip. It is controlled effectively by Amistar, Twist, Scotts Octave and Bravo 500. With growth now slowing down it is important, on susceptible species such as Ceanothus and Viburnum, to apply before winter dormancy.
Weed control: This is the best time to be applying Roundup to perennial weeds. As the plant dies down for the winter the glyphosate is taken into the plant; it continues to remain at a low level of activity all winter and suppresses re-growth next season, giving you a head start on the weeds. With patches of mare's tail, Challenge seems to be consistently the best control product for rapid knockdown.