Phosphorus is important for early root and shoot development, providing energy for plant processes such as ion uptake and transport. Roots absorb phosphate ions only when they are dissolved in the soil water. Phosphorus deficiencies can occur even in soils with abundant available P, if drought, low temperatures, or disease interfere with P diffusion to the root, through the soil solution. These deficiencies will result in stunt root development and inadequate function.
At the tuber initiation stage, an adequate supply of phosphorus ensures that optimum number of tubers is formed. Following the tuber initiation, phosphorus is an essential component for starch synthesis, transport and storage.
Recent research suggests that modifications to P fertilizer, such as polymer additives, humic substances, and coatings may be beneficial in improving P uptake and potato production