Researchers from the Islamic Azad University (Mahabad, Iran) studied the effects of different Potassium:Calcium ratios (K:Ca; 1.6, 1.4, 1.2, 1, 0.85 and 0.6) in nutrient solutions on the quality of remontant Selva strawberries grown using soil-less techniques.
The highest and lowest leaf number and leaf areas were observed for K:Ca ratios 1.4 and 1 respectively. The highest values of fruit pH, conductivity, total soluble solid/titratable acidity ratio, vitamin C content, ellagic acid and colour were observed for K:Ca ratio 1.4. K:Ca ratio 1.6 produced strawberries with a higher protein content, while K:Ca ratio 0.85 was more effective on fruit firmness.
Source: Haghshenas Masoud, Arshad Mousa, Nazarideljou Mohammad Javad, 'Different K:Ca ratios affected fruit color and quality of strawberry 'Selva' in soilless system', 2018, Journal of Plant Nutrition, Vol. 41 (2), pag. 243-252.