please give us a pic of the whole plant...

is it potted ... if not.. when planted ...

it would be helpful to mention UAE when starting a post ...

is there any pattern???? ... as in shedding older leaves .. etc??? ... even evergreen plants.. shed older needles ... usually in fall or winter ... when the sun is in decline ...

i cant really focus on your pic .... 2 appears like something affected by sucking insects ... or nutrition issues ... and that is where the pic falls short ...

my bigger question... is why are the leaves all not the size of 5??? .. hence suspecting transplanting ... or poor media ...

if there was some extreme shock ... to the point of dwarfing the leaf size ... and 5 is a newer larger leaf ... then it would not bother me a lot.. if the plant was shedding the older leaves grown small... during the stress event ... more history please ...

ken

It could very well be nutrient deficiency and/or a water issue. An abundance of certain salts block the uptake of several nutrients. Excess water can do the same.

You should call your local extension office to get the proper watering requirements for your particular area and have the soil tested to determine nutrient availability and need.

Umm, doubt OP has a local extension service office.

Even so, consulting with a local agricultural source in the United Arab Emirates would be useful.