Hi Jonatan,

You could find detailed info on the following link. However, having looked at the symtoms, it seems to me that it is not a disease but rather a sign of nutritional deficiency (in particular that of micronutrients).

I am sure that a search on google will allow you to get more info in this regard

http://www.cabi.org/isc/datasheet/2207

I have a question. Do you know if the second picture is an Acacia plant previously had turned yellow and then lost the leaflets? or do you think that the symptoms are independents?

Hi Jay,

Thank you for answering. Your opinion could be a big help for me to identify this symptoms. Many thanks for sharing the link. I will try to find more info about this fact.

Thanks again,

Regard.

Hi Luís,

I do not know if in the second picture previously the leaf had turned yellow, but I have other picture that could be interesting for you because I think that the second symptom is diferent than first picture.

Thanks for you interesting,

Regards.

I agree that I seems like nutritional deficiency - maybe tree has problems with roots or abnornal soil or any other stress factor. Does it grow in forest?

Thank you for answering Timur. Yes, it grow in Pinus pinaster forest in NW of Spain.

I sure that this disease is non-fungal and non-bacterial, and non-infectious at general - if roots of trees have no problem. But do you remember about plant-bacterial symbiosis in root nodules of Fabaceae s. l.? Perhaps there is any problem in roots because chlorosis (yellowing of leaves) usually is symptom of low rate of nutrients like nitrogen and so on.

Yes, perhaps there is any problem in roots or related with plant-bacterial symbiosis. On the other hand, we analysed the nutrients and were: 0.4% Nitrogen, 8.2% Carbon, 349(mg/kg) Potasium and 313(mg/kg) Phosphorus in this area. Also we saw some hemiptera in this area which are vector of bacterial diseases than probably could be affecting. For this reason I had doubts. 

Thank you for your interesting.

Regards.