Terrace Gardening - Mango leaves burn decease, please help

Hello All,
I have started terrace gardening one year back. I am growing fruit plants ( Sapota, Mango, Orange, Lemon) and vegetables ( Chillies, Spinach, Brinjal, Okra) with some success.
I have used red soil with vermi compost, Neem cake and bio granules. For fruit plants I have used 2x1 feet cement rings stacked ( 2 or 3 rings). I’m facing issues with mango plants.

  1. Leaves edges are burnt , even new leaves getting burn after some time. 
  2. New twigs are getting similar issues
    I cannot see any insects on the leaves. The pots have good drainage and I water once in 2 days. I don’t issue of over watering … 

Another thing - I have observed galls on the vegetable roots (okra, tomato). This shows presence of root knot nematodes (RKN) in the soil. I have read in some forum that neem cake keep RKN in control so I regularly add neem cake to plants (once in a month) and I also rotate vegetables with RKN immune ones.

Can anyone please suggest how can I cure mango leave burn.
Is it because of RKN in the soil or some other reasons.

I’m attaching photos of dying mangoes and the ones with few fruits.

Thank you.

Sanjay Kumar

Did some more research on this. This seems to be mainly 2 reasons. 1. Too much salt in the soil 2. Anthracnose fungal attack.
I normally use vermicompost , bio granuels and neem cake . Can these organic matters increase salt levels ? Any suggestions ?
Anthracnose seems to be incurable, however I did copper based fungal spray as suggested in few forums. Let’s see if there is any improvement.

This is due to lack of Nutrition to the Tree Plantations. Trees are not suitable for Roof Garden. In the Pots Root zone cannot be developed. Because of that reason Plants could not sufficient Nutrients . Hence that situation may occur. If you Plant those Trees in Open Garden it will Grow Perfectly. As far as my observation is concerned the burning of leaves of the Mango and sapota are due to insufficient Nutritions and not because of any disease.
for Vasudha green farms,

I have one of my friend having mangoes in pots with normal yield. The tree is more than 10 years old and looks fine (pic attached)…
Anyway, thanks for the suggestions.