Palm Tree Forum

I think I had some bad advise from my local agriculture supply;
Here in southern Portugal, we're suffering with heavy red palm weevil attacks this year.
As a preventive measure I was advised to regularly use a powerful pesticide mixture [imidiclopride and cypermethrin] and also to add fertilizer to the mix.
This is then injected or dribbled into the crown of each tree.

My trees are between 5 and 10 years old.

it was fine for the first 6 or 8 months, but then I started to get dying top leaves. Assuming the problem was the weevils [they're all over the place] we doubled the treatment.

As things got worse, I called a tree specialist who told me on the phone that with the dose I'm using, there's no way there can be weevils in the tree.

Belatedly, I realized I'm killing my trees, probably with the fertilizer.

sold here as "aminotec" it seems to be mainly compounds of nitrogen and some amino acids.

There is tip necrosis all over, and brown dead patches appearing at random points along the leaf spines. The affected leaf then collapses. This is even happening with some baby leaves now.

The rainy season is just starting here; should I let nature do the work, should I add water, if so, at the roots or in the crown?

Help!