An integrated approach to control (Apple powdery mildew)

AHDB funded research in Project TF 223 (Improving integrated pest and disease management in tree fruit) investigated ways of integrating novel and alternative control products with conventional fungicide products within powdery mildew spray control programmes. The purpose was to find ways of reducing reliance upon conventional fungicides, whilst maintaining an equal level of control.

  • Initial work assessed alternatives to conventional fungicides and three products were identified with ability to improve tree health and increase the tree’s ability to resist disease. These included Cultigrow (a biostimulant based on flavonoids), Trident (a silicon-based nutrient) and Mantrac Pro (manganese nutrient).
  • SB Invigorator (a blend of surfactants) and the adjuvant Wetcit (a natural adjuvant based on alcohol ethoxylate) are used in combination with plant protection products and offererd a physical barrier to powdery mildew infection.
  • When combined with conventional fungicides in the project in weekly spray programmes, by switching between alternative products and fungicides, similar levels of control to a routine seven-day fungicide programme were achieved in both Gala and Braeburn orchards.
  • Three spray programmes offered similar control, two based on Cultigrow applied monthly, with either Mantrac or Trident applied every two weeks, the third based on Trident and Mantrac alternating every two weeks. Conventional fungicides were applied in the weeks between the alternative products. SB Invigorator was applied as a separate spray (should not be mixed with other products) in all programmes and Cultigrow was used with the adjuvant Wetcit. Full details of the programmes used are available in the final report of Project TF 223.
  • The standard seven-day conventional fungicide programme achieved the best early season control for both Gala and Braeburn, but by July, all three alternative programmes were performing as well as the standard.
  • Starting all programmes with the seven-day standard fungicide programme for the first few sprays would probably have resulted in comparable control throughout the season and any growers considering this approach should follow this experience.
  • Employing one of the alternative programmes therefore offers similar levels of mildew control and fruit quality but with half or reduced numbers of conventional fungicides.