Visual symptom and tissue nutrient contents in dry matter and petiole sap for diagnostic criteria of phosphorus nutrition for ‘Seolhyang’ strawberry cultivation

Abstract

‘Seolhyang’ strawberries (Fragaria ananassa Duch.) were grown in a soilless substrate with fertigation solutions to evaluate the effects of six different P concentrations (0, 0.5, 1, 2, 4, and 6 meq·L−1) on the growth and nutrient contents in dry matter of above-ground tissue and petiole sap. The changes in electrical conductivity (EC) and pH of the root substrate were also investigated. Deficient and excess concentrations of phosphorus, such as 0 and 6 meq·L−1, seriously restricted the plant growth. These two treatments showed the least values in leaf number, plant height, leaf length and width, petiole length, and fresh and dry weights. The solution containing 1 meq·L−1 of phosphorus showed the greatest plant growth compared to the other treatments. The macro-element contents such as P, K, Ca, and Mg showed increased tendencies as P concentrations were elevated but, micro-elements such as Fe and Mn showed decreased tendencies in dry matter of above-ground tissue. When P concentrations were elevated, the pH and EC in the soil solution of root substrate decreased. Considering the crop growth and tissue nutrient contents, the P concentrations should be between 0.5 to 2.0 meq·L−1 and the P contents in the dry matter and petiole sap were 0.23 to 0.62% and 205 to 305 mg·kg−1.