How to influence strawberry quality

Strawberry fruit consists of approximately 90% water and 10% total soluble solids. They are a good source of folate and potassium, as well as dietary fiber, manganese and antioxidants.The fruit is high in vitamin C and consumption of 10 fruit per day virtually meets all of the recommended dietary requirements for this vitamin. The main soluble sugar components are glucose and fructose. The primary acid is citric acid. Strawberry flavor is a key characteristic and is a complex mix of the sweetness, acidity and aroma of the fruit. The most intensely flavored fruit have a high TSS and also acidity.

Balanced crop nutrition will improve quality

Good crop nutrition will ensure the production of fruit that handles well and has a longer shelf life with the right balance of sugars and acidity plus a good aroma and taste.

All nutrients are needed by plants but potassium, nitrogen, calcium and boron have particularly important roles in achieving high quality.

• Potassium plays a key role in increasing fruit sugars, acidity and improving its taste
• Nitrogen – particularly nitrate forms – used at adequate rates during flowering and fruiting – will maintain taste and acidity without encouraging rots
• Calcium – is essential to maintain fruit integrity, health and a longer shelf-life, with reduced damage when handling
• Boron – also helps to maintain good fruit strength

Boron deficiency causes malformed fruit

Boron plays a key role in fruit quality with poor supply leading to smaller, malformed fruit.

Potassium improves key quality characteristics

Potassium is particularly important in terms of berry quality providing a high sugar and acid content, and a good taste to the fruit.

Nitrogen excess leads to softer fruit

Excess nitrogen during fruit growth and development has an adverse effect on fruit quality. It increases disease susceptibility and the softening of fruit. This leads to a shorter shelf life and fruit that is quicker to rot. Maturity can also be delayed and fruit malformed, resulting in reduced yields.

Excess nitrogen also encourages diseases such as anthracnose crown rot. Fertigation can help ensure that applied nitrogen is better utilized by the plant and not available to encourage rots. Although, even under more controlled fertigation systems, high nitrogen rates may still result in greater disease severity.

Other factors influencing strawberry quality

• Variety selection is particularly important and producers should select resistant cultivars with the quality characteristics that most suit their intended market.
• Use of appropriate mulches or growing systems to minimize soil contamination is important to physical quality.
• Good hygiene, sanitation and appropriate in season fungicides and pesticides will help to provide fruit that is less at risk of pest and disease damage.
• Maximizing growth through appropriate irrigation will help ensure good water and nutrient flow to the developing fruit.
• Refrigerated storage and transport, utilizing controlled carbon dioxide environments will help to maximize the shelf life of the fruit that is picked.