Influence of soil and spray applications of phosphorus on potato yield, dry matter content, and chemical composition

Abstract

A 22 factorial experiment compared soil applications of treblesuperphosphate supplying 360 pounds P2O5 per acre with spray applications of monobasic sodium phosphate (NaH2PO4·H2O) supplying about 10 pounds P2O5 per acre each season on potatoes in 1959 and 1960. Treblesuperphosphate applications markedly increased early growth, US No. 1 yield, and dry matter content of tubers in both years. In 1960 treblesuperphosphate decreased the potassium content and tended to increase the phosphorus content and to decrease the nitrogen and magnesium content of the tubers. Monobasic sodium phosphate spray applications produced varying results. In 1960 when no phosphorus was added to the soil, early growth was increased by these phosphorus sprays. Phosphorus spray treatments tended to increase the dry matter and phosphorus content of tubers and tended to decrease the nitrogen content.