We’ve started the spraying operation much earlier this year to stop the fruit fly (Bactrocera oleae, or Dacus oleae) laying her eggs in the olives.
The spray is a suspension of fine clay powder (between .5 to 1.5 microns) which covers the fruit so that when la mouche turns up she finds a film of clay on the olive which sticks to her legs, so she flies away. The treatment is as effective as chemical spray but of course clay is inert, so biologically acceptable. After harvest, it is easily washed off before pressing.
For many years, the treatment has been widely used for the same reasons against the pear and apple fruit flies, and, once the French olive growers association, AFIDOL, finally authorised its use on olives two years ago, they’ve been pushing everyone to use it – because it’s ‘bio’. However, the agricultural co-op where we bought ours say they’re not selling much to anyone else, so it seems olive growers are sticking to chemicals: perhaps on the “stay with what you’re used to” principle.
Behind Edward, there is a view of the olive trees in the ‘Vallon’ almost up to the foot of the cliffs.