October 8, 2008
From the Nursery
By Adlam, John
Whitefly With predators, add Majestik, Nemolt, SB Plant Invigorator and Mycotal into your integrated pest management programme. Mycotal is a useful control product especially in humidity levels above 80 per cent under protection. If predators are not used, apply Gazelle, Oberon, Toppel 10, Decis or Gyro. Spraying three times at five-day intervals to ensure all subsequent generations are controlled gives the best adult control programmes. Exempter or lmidasect 5GR granules in the growing media give longer term control. Aphids I have come across aphids on a wide range of outdoor and protected crops. Make a close check of crops such as Euonymus, Senecio, Lonicera, roses, honeysuckle, Hebe and a range of autumn bedding and herbaceous plants. I am seeing plenty of parasitised aphids too. so continue using products such as Chess WG, Plenum WG, Stalwart, Majestik, SB Plant Invigorator or Aphox to encourage natural predators.
Feeding Increase potash levels in container and field-grown stock. Potash hardens the cell wall and gives better low temperature protection. If liquid feeding, change to a 1:0:2 product or a 1:0:2 topdressing.
Drains Make sure that all container bed drains are in working order and cleaned out. Check the drainage of sand beds and stir up the sand if percolation is low because of moss, compost and weed growth. Strim ditches to remove large clogging weed growth, so allowing unimpeded water flow during the wet winter periods. Autumns are now often wetter, so this work needs doing soon.
Powdery mildew This disease is still showing on Acer, Quercus and Crataegus. Use Nimrod or potassium bicarbonate if patches of white growth are still around. Follow up with Systhane 2OEW.
Irrigation How efficient has your watering process been this year? Go through the HDC factsheets on water efficiency and carry out a test with the cups. The water calculator supplied on CD can help you use water more efficiently.
Downy mildew Keep checking susceptible species in cool, humid weather such as pansy. Hebe and grapevines. Spray ornamentals with Aliette 8OWG. Fubol Gold WG. Proplant or Filex. Stop spraying grapevines from now and don't restart until after harvesting.
Scale Control adult scale insects now. Use Chess WG at the SOLA rate, Toppel 10OEC or products containing nicotine.
John Adlam is managing director of Dove Associates
Copyright Haymarket Business Publications Ltd. Sep 4, 2008
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