How to balance TSS and acidity in apples

The sugar/acidity ratio of fruit is what gives fruits characteristic taste and flavour. Balanced crop nutrition programmes help growers manage an acceptable TSS/Acidity balance in the fruit.

Total Soluble Solids (TSS) is therefore of extreme importance to measure the quality of apple. Referred to as oBrix, TSS is assessed by refractometry or near-infrared spectroscopy and can be used to check fruit maturity and ripeness, important to determine harvest timing. A balanced crop nutrition can influence TSS content of fruit.

Nitrogen and potassium both have a positive effect on fruit sweetness

Nitrogen has a positive effect on the soluble solids content of apples. Potassium also plays an important role on sweetness, measured by oBrix, as shown in trials in India. °Brix is used to approximate the TSS content because the soluble sugars usually represent more than 75 - 85% of the soluble solids.
Nitrogen and Soluble Solids in apples
Potassium and TSS Content in apples

Magnesium can increase acidity

Magnesium and apple Acidity

Apple acidity is a relevant characteristic for both fresh and processing markets. It is one of the main group compounds determining flavour. The higher the level of acidity, the more tart the flavor and the better the thirst-quenching properties of processed soft drinks. 

Magnesium has a slight effect on fruit acidity.

Recommended fertilisers for apples

Apple fertiliser and crop nutrition advice
Apple fertiliser and crop nutrition advice

Looking for even more information ...

If you would like more information and would like to speak to a fruit specialist or one of our area managers or agronomists please find all their contact details here.

Contact your local Yara area manager or agronomist


Where can I buy Yara fertiliser ...

If you would like to find your nearest Yara supplier or merchant simply use this searchable map with all their contact details here.

Where can I buy Yara fertilisers >