Effect of Potassium Source and Dose on Yield and Quality of Strawberry Fruit

Abstract

The purpose of this research is to investigate the effect of potassium fertilization source and dose on productivity and quality parameters of strawberry. The trial was conducted in 2016-2017 at the experimental greenhouse of Hassan II Institute of Agronomy and Veterinary Sciences in Rabat. Strawberry plants of the cultivar “San Andreas” were planted on November 6th in 12 liter pots equipped with a gravity fertigation system. The experimental design was a split-plot with eight treatment combinations of two potassium fertilizer sources: 1) Potassium Sulphate for the whole growing cycle (PS/PS); 2) Potassium Nitrate during the vegetative period and Potassium Sulfate during the fruit production period (PN/PS) and four potassium fertilizer doses: 100, 200, 300 and 400 kg/ha of K2O replicated thrice. Potassium sulfate source was superior to potassium nitrate on the improvement of productivity and quality parameters of strawberry fruit. Potassium sulphate improved the number of flowers by 16%, fruit production by 21%, sugar content by 3%, and titrable acidity content by 0.5 g/L. The highest yield was recorded in plants receiving 300 kg/ha K2O as potassium sulphate. The 300 kg K2O/ha dose gave also superior results regarding quality parameters of strawberry fruit. This optimum potassium dose enhanced number of flowers by 35%, fruits produced by 44%, sugar content by 25% and titrable acidity content by 0.9 g/L.