I have observed these type of symptoms in my experimental field also around 30-40 days ago, which did nor recover much. The growth is stunted even after copious rainfall after the symptoms were observed. We have sprayed, Zn and Fe separately and in combination, but the response was not observed. I will update my field photos soon. I am suspecting it to be a pathogen in soil that is causing the damage. Mainly because normal plants are interspersed in between the affected ones.