Cordyline, Phormium and Yucca Apply Octave or Switch to prevent leaf spotting. As these plants grow from the base, damage will move up the leaf and become more visible.
Vine weevil September is a key time for egg-laying. Start applications of nematodes to vulnerable plants, particularly crops without active compost controls. Insecticide drenches can be made with Intercept 70WG or Equity or consider Nemasys L, which works in compost temperatures above 5 degsC. Larvae start developing about six weeks after egg-laying.
Downy mildew Check impatiens, pansy, hebe, grapevines and roses. Spray ornamentals with products including Amistar (SOLA 2009-0443), Aliette 80WG, Filex/Proplant, Fubol Gold WG (SOLA 2010-2567), Previcur Energy (SOLAs required), Paraat (SOLA 2011-2067), Revus (SOLA 2008-2867), Stroby WG, Subdue or Valbon (SOLAs required). Do not spray grapevines until after fruit has been harvested.
Plant quality Consider applying products such as Wiltpruf S600 or Orosorb onto foliage exposed to the elements. This will help to extend plant sales potential into autumn.
Scale insects Control adults and their new generation of eggs by using Chess WG (SOLA 2008-2834) or Toppel 100EC (non-IPM).
Bud blindness Low temperatures and low light levels affect concentrations of plant growth regulators in crops, leading to fewer buds being produced, especially with long periods of dull, cloudy weather. Move vulnerable plants outside to a sheltered but sunny position.
Gleditsia Pea leaf gall is still active. Spray with chlorpyrifos or Hallmark WZT (SOLA 2008-2944) where leaves have formed into a pea-sized ball.
Revocations Repulse (MAPP 07641) has an end use date of 30 September 2011.
Slugs Wet weather encourages this pest so apply Ferramol pellets to vulnerable plants. Parasitic nematodes are also effective in prolonged wet conditions. The formulation for Decoy Wetex makes it effective for longer in field situations.
John Adlam, Managing director, Dove Associates