New leaves emerging from the whorl are usually green, because the plant mobilizes available phosphorus to the youngest leaves. Phosphorus deficiency symptoms often occur as young plants are exposed to good growing conditions following cool and often wet conditions. This results in a lag phase where vegetative growth exceeds the roots' ability to supply phosphorus. Young plants are especially vulnerable because their root systems are small and phosphorus is immobile in the soil solution. Any cultural or environmental factors which limit root growth will aggravate deficiency symptoms.
Acidic soil can also intensify phosphorus deficiency symptoms.
Acidic soil also reduces root growth, which is critical to phosphorus uptake. Leaves normally regain green coloration when further root exploration occurs, especially when favorable growing conditions prevail. However, phosphorus deficiency will reduce yield by delaying maturity, stunting growth, and restricting energy utilization. Treatment options to remedy phosphorus deficiency have modest short-term effectiveness, since phosphorus is immobile in the soil solution. Thus, root exploration into the amended area is required for plant uptake.