Coconut leaves turn yellow color-reason and remidies?

Good day Every body,
The pictures posted are from my farm.These plants are “Godavari Ganaga”,which were sourced from Ambajipet,Andhra pradesh, Coconut board. Planted date is 11/01/2016.Farm is near by T.P.Gudem,W.G.DT.,Andhra Pradesh.
Recently, we have done “Ground nut” as inter crop.Now crop sprouted nicely, as you see in the pictures.Please also note that earlier inter crop was “Mirchi”
Now it is observed that 3 to 4 plants leaves are turning in to yellowish color as attached in the pictures.
Now my doubt is
1.is it due to tied up the leaves? or
2. due to deficiency of nutrients? or
3. Any diseases?.
Here people are expressing as “PANDU TEGULU”
As per our forum guidelines and similar topics,i am presuming as nutrients difficiency!. Like lack of N,S,MG&ZN.
Am i right?Please advise me on this.
As i was listening, climate was very hot and humid,than normal, now a days.Hence, itold my farm helper to un tie the plants as a first precautionary measures.
Kindly advise me.
Prakruthi