Mobility of phosphorus and its impact on radish top development

Phosphorus deficiency often limits the plant productivity because of its low mobility in soil and the root system. Its low mobility may retard the ability of a plant to acquire this nutrient. To explore its mobility in plant and its role in plant top development, a soil pot culture experiment was conducted using zero, 10 and 20 mg/l phosphorus in radish (Raphanus sativus L.). The deficiency symptoms were apparent at the very early stage of growth in zero phosphorus (control) in the form of chlorosis of older leaves at the margins near the tip, which continued till whole leaves were chlorotic and dried. Fresh and dry matter increased with phosphorus application. Leaf area and leaf area ratio were also increased. The phosphorus level in plant tissue was also found to be increased with the increase in phosphorus concentration in soil and time. Soil analysis indicated the residual accumulation of phosphorus. Application of phosphorus in soil not only promoted its mobility into the plant system but also increased the plant growth significantly.