Yellow patches appear in leaf margin then these patches join, lead to yellowish leaf.  Dark spots will appear on the affected portion.  Curling of leaf.  Basal portion of leaves only shows the symptoms.  Yellow discoloration of leaves appear from the base and top leaves remain green the bluish green leaves show black to brown tips internodes sharp and pale yellowish symptom appear on the margin and in-between the veins.

Soil application of Murate of potash spraying of 1% potash at flowering stage.