Changeable weather Warm days and cool nights can increase the risk of damage on soft growth. Make sure that fleece or Cosytex is available to cover vulnerable, saleable crops and that someone is accountable for doing it to avoid any unnecessary crop damage. Artificial covers help plants adjust slowly to changing temperatures. Applications of Cropaid or Frost Protect (Compo) may help to prevent damage before frosts set in.
Powdery mildew Persistent infections can be controlled at this time of year using food-grade potassium bicarbonate or Nimrod.
Soil phosphate levels This nutrient is easily locked up in soils and is not very mobile, so it can remain at high levels for many years. Carry out a basic nutrient test in fields where plants are looking pale and lacking vigour to see whether phosphate levels are to blame. High levels will suppress growth and plants’ ability to access trace elements such as iron.
Perennial weeds Apply Roundup now to persistent perennial weeds in established woody field-grown crops. Also, Chikara, Dow Shield 400 (EAMU 2013-0514), Sumimax (EAMU 2008-2881), products containing pendimethalin or Ronstar Liquid will provide good dormant season clean-up to selected plant genera. Some can be tank-mixed for more effective results. Make sure that soils are moist and fine for effective herbicide applications.
Phoma Still evident on ceanothus, viburnum and vinca. Control damage using Octave or Switch.
Autumn bedding Watch out for downy mildew on pansy and viola. Products for use now include Amistar (EAMU 2009-0443), Fenomenal (EAMU 2013-1990), Fubol Gold WG (EAMU 2012-0217), Pergado Uni (EAMU 2012-1605), Paraat (EAMU 2011-2585) or Signum (EAMU 2012-2141).