Phosphorus deficiency-Cocoa

Symptoms
Symptoms appear first on older leaves. They turn pale green, mainly between the veins. Later on, the leaf tips and margins become necrotic. New growth is restricted: Leaves remain small and slim, and the tree has a smaller leaf canopy. Internodes of newly grown twigs remain short. With severe deficiency, leaves often fall off while the stipuleis remaining at the branch.

Reasons
Phosphorus deficiency. Early in the plant’s development Phosphorus is particularly important for root and shoot growth, later for the formation of flowers and cherelles in cocoa. At low phosphorus availability, the P adsorbing roots are reduced, and P cannot be taken up from the soil