Stone Fruit

The right combination of an optimum fruit load on the tree and a high fruit weight or size is essential to achieve high stone fruit yields.

Potassium is a key driver of fruit size or weight and alongside nitrogen required in large quantities throughout fruit development and ripening.

Whereas the effect of nitrogen on the number of fruits per tree is not clear, particularly phosphorus and magnesium have been found to increase fruit number. Boron, iron and zinc also support higher yields by helping the tree to produce more fruits.

Whereas the effect of nitrogen on the number of fruits per tree is not clear, particularly phosphorus and magnesium have been found to increase fruit number. Boron, iron and zinc also support higher yields by helping the tree to produce more fruits.

There are a number of variables that define stone fruit quality requirements. Quality standards differ depending on the stone fruit type, growth region and the market.

Firmness of fruit flesh is affected by a wide range of parameters. High temperature result in a loose cell structure, reducing the firmness of the fruits.

Splitting or cracking, usually as a result of rainfall prior to harvest, is a serious problem in all stone fruit, especially in cherries and plums, as it renders fruit unmarketable.

Produce buyers constantly prefer redder fruit. Some varieties develop redder colour than others. Although the red colour differs for each variety, it can be maximized in any of them by managing light intensities (shading, pruning) and nutrition.

The main cause for internal breakdown is an inadequate physiological growth leading to a breakdown of internal tissues. Fruit flesh browns from fluid oxidation, becomes leathery or mealy and there is a loss of juiciness and flavour. In severe cases, tissues become spongy.

Pitting is a significant problem in cherries as a result of poor handling and storage conditions. These small indentations in the skin only show during cold storage, but can make the fruit unmarketable.

Storage rots are caused by a range of pathogens including Botrytis cinerea, Geotrichum, Alternaria, Phomopsis, Penicillium sp, Rhizopus, Saccharomyces sp, and Cladosporium sp.

Healthy stone fruit trees are the key to productive, high-yielding and top quality crops. A balanced crop nutrition is essential to promote health and minimize nutrient related disorders in stone fruit.

The TSS content of the fruit is usually obtained from assessing the oBrix of the fruit. The TSS or ‘sugar content’ measures and includes the carbohydrates, organic acids, proteins, fats and minerals of the fruit.

Storage rots are caused by a range of pathogens including Botrytis cinerea, Geotrichum, Alternaria, Phomopsis, Penicillium sp, Rhizopus, Saccharomyces sp, and Cladosporium sp.

Peach and nectarine trees can produce fruit from the second year onwards and around 80-95% of flowers need to be thinned in order to produce marketable fruit.

Around 40 million tonnes of stone fruit are produced annually worldwide across 5 million hectares.

Most nutrients, namely N, P, K, Mg, B and Mn are stored and retained as reserves in the tree buds, trunk and roots.

It is important to incorporate good levels of phosphorus within the root zone before planting the orchard. In established orchards, dry-applied fertilizers can be broadcast across the soil surface or banded underneath the leaf canopy drip-line.

Peach, nectarine, apricot and sweet and sour cherry production are within the genus Prunus.