Papaya ringspot diseases spread through sucking pest i.e aphid ( Aphis gossypii)
If Virus comes in season its very difficult to control.
Now you can do it.
Rogue out affected plants immediately on noticing symptoms.
Spray Imidiclopride 17.8% SL @10 ml/10 liters of water.
From next time of planting please follow the following practices.
1)Raise sorghum/maize as a barrier crop before planting papaya.
2) Do not raise cucurbits around the field.
3) Use healthy and diseases free plant material for planting purposes.