Berries

This type of fruit is characterised by the presence of a reddish colour, both on the skin and inside. Red fruits are mostly berries, and belong to the Rosaceae. family. Their strong red colours are due to pigments synthesised by the plants themselves, most notably including antioxidants which are highly beneficial to human health. Many of these fruits are wild, and so have not traditionally been cultivated. This group of red fruits or “fruits of the forest” can include: blueberries, raspberries, blackberries, strawberries, strawberry plants, cherries, strawberry trees or gooseberries.

Although some can be found throughout the year, most are seasonal fruits with the warm months being the peak. The main nutritional needs of these crops are:

Macronutrients in berries

Nitrogen

This is a nutrient which stimulates plant growth in general. Red fruits do not require fertilisers with excessive levels of nitrogen, with it being restricted mainly to the plant’s vegetative growth phases.

A lack of nitrogen causes pallor or yellowing of the entire surface of the leaves and all tissues in general.

Phosphorous

Phosphorus is mainly involved in the development of the root system. It can stimulate vigorous growth and development of the plant, and encourages flowering and fructification, thereby increasing the quality and quantity of its fruits.

A lack of phosphorus causes the leaves to take on a slightly purple colouration.

Potassium

Potassium is involved in osmotic regulation and in the transport of sugars to the fruit. It provides mechanical resistance to the fruit and increases post-harvest life.

A lack of potassium causes necrosis in old leaves and internerval chlorosis in young tissues. In addition, the fruits weigh less, with a smaller size and sugar content.

Magnesium

Magnesium is an element that forms part of chlorophyll and is essential for forming other pigments such as carotenes or xanthophylls. It promotes plant resistance to drought and disease. In addition, it can activate the metabolism of carbohydrates and proteins.

A lack of magnesium produces chlorosis on the margins of the leaves, with the centre remaining green.

Calcium

Calcium is involved in the formation of cellular structures. Specifically, it promotes the filling and weight gain of the fruit by encouraging the stretching of its cell walls.

A lack of calcium causes the death of growing apexes, weaker stems and less healthy fruits which will be susceptible to damage or disease.

Micronutrients in berries

Boron

This micronutrient influences the formation of the pollen tube. It is of vital importance in raspberry and blackberry crops, because as these are polydrupes, any lack of it may cause serious deformation. A lack of boron causes chlorosis at the tips of the leaves, which may appear smaller or even deformed. The viability of the setting may also be affected.

Iron

This micronutrient is involved in essential redox reactions and participates in chlorophyll biosynthesis, thus increasing photosynthetic activity. A lack of iron may manifest itself as internal chlorosis, mainly in young leaves which will assume a yellowish colour.