Olive stop + Embark + surfactant combined with good timing will do a pretty good job.

There is another much more potent material but I don't recall the name off hand that will give excellent results but disfigures the leaves and all other plants in the yard have to be covered which is pain.

 

Maintain is the other stuff.

 

when do I apply it?

 

The maintain you can apply now until the flowers set I believe. The fruit eliminator you have to apply when the flowers are open which is about 80 degrees give or take. The tricky part is a droplet of the product has to hit the pistol or stamen I forget which one but it is nearly impossible to get 100% coverage, you really need at least two treatments about 10-14 days apart. The maintain is much more forgiving but don't quote me it has been many years since I sprayed or read a label. look it up for yourself. Read the labels, you know the drill.

 

AZ, I did one olive spraying season in Phoenix and it was amazing how consistent the olive flowering was. If I remember right I think trees at the south end of the valley hit their peak bloom first and then over a week ar two like a wave it moved up the valley.

In N.CA olive fruit control was totally unpredictable. I basically quit selling it because the mountainous terrain created so many different microclimates that about 50% control was about all I could expect (w/o maintain). Although I suspect a landscape maintenance guy could do better being on the property regularly.

 

the olive trees are located in the lawn of this property will this hurt the grass (tall fescue)? And if I understood this correctly I need to try to spray 100% of the leaves on the tree.

 

Oh and what type of applicator in your opinions. I have a back pack sprayer at the moment.