Apricot

It is one of the fundamental elements of plant nutrition, since it is included in the composition of chlorophyll.

The stone fruit tree continuously absorbs nitrogen from bud break to ripening, and its greatest need is at three time points. Firstly, when active growth restarts after bud break. Secondly, at flowering whereupon it is frequently found that the nitrogen is not readily available at that time. Finally, a third period where nitrogen is very important is when the fruit begins to grow rapidly.
Despite this, an excessive nitrogen supply can have a negative impact on the quality of stone fruits by reducing flesh firmness and sweetness, diminishing red color appearance and increasing susceptibility to disease and damage.

On the other hand, nitrogen deficiency can lead to small fruits with poor flavor. Stone fruit trees that are deficient in nitrogen tend to give a lower yield because of a shorter period of leaf maintenance, which leads to a shorter period for the accumulation of reserves during the post-harvest cycle.

A nitrogen application rate of 60 to 130 kg/ha/year is usually considered adequate for stone fruits.

Phosphorus is a vital component of adenosine triphosphate (ATP), the “energy unit” of plants. ATP forms during photosynthesis, has phosphorus in its structure, and is active from the beginning of seedling growth through to the formation of fruits and maturity.

Phosphorus is important for the general health and vigor of all plants including stone fruits. Some specific growth benefit that have been associated with phosphorus are: a stimulation of root development, increased branch strength, improved flower formation and fruit production, more uniform and earlier ripening, improved crop quality, increased resistance to disease, and more vigorous development throughout the growth cycle.

Phosphorus is an essential nutrient for all parts of the tree as it is required for membranes, energy molecules and nucleic acids. In cases of phosphorus deficiency, the fruit are more highly colored and ripen earlier but exhibit surface defects and poor flavor.

Leaf samples collected in mid-summer should have P values between 0.1 and 0.3%. If values drop below 0.12%, the trees will almost certainly benefit from the addition of a phosphorus fertilizer. Phosphorus deficiency in young leaves of stone fruit trees can be recognized by a dark green, purple, or bronze color with leaves looking stained. Petioles stand upright connecting with the leaf in a green half-moon shape with a purplish-red leaf margin. In severe cases, the edges of older leaves become dark brown and necrosis occurs, leading to early defoliation. Consequently, fruits remain small and do not reach full maturity. The fruits have a bland color, are hard and tend to be rather tasteless.

It also helps to promote the storage of reserves in different parts of the plants. Potassium plays a role in orchard vigor and yield, and it contributes to the neutralization of formed organic acids. It also promotes respiration and activates growth. This is an important health factor for trees because it facilitates the proper distribution of reserves between different parts of the tree. It intervenes in the regulation of the opening and closing of stomata, thereby playing a role in improving drought resistance via better water use efficiency.

Potassium promotes the setting and advances the maturation of the fruits. It also helps protect against frost. In cases of potassium deficiency, stone fruit productivity, quality and storage potential are negatively affected. Poor fruit color (either a lack of color or dirty looking fruit) is observed in stone fruit trees suffering from potassium deficiency. Sugar content of fruits is also reduced. When potassium accumulation is excessive, total acidity decreases and fruit pH becomes unacceptably high, which may impact storage quality.

This nutrient is thus usually taken up readily across a range of orchard soil conditions. In the tree, it is incorporated into certain amino acids (cysteine, methionine) and subsequently becomes part of certain enzymes, vitamins and oils. Once in these complex molecules, sulfur is not easily mobilized within the plant. Deficiency symptoms therefore will occur in the young tissue first.

Senescing leaves efficiently retrieve sulfur. As complex molecules are broken down, sulfur is converted into sulfate (SO₄^2-), which is readily transported out of the leaf and into the rest of the plant.

All proteins (and therefore enzymes) need sulfur to function, as disulfide bonds stabilize their structures. Sulfur also plays a key role in nitrogen metabolism. Sulfur contributes to the aroma of certain fruits through volatile sulfur compounds.

It improves both leaf and fruit quality. Calcium is involved in many plant processes including cell elongation, cell division, germination, pollen growth and senescence. One of its most important functions is the maintenance of membrane permeability and cell integrity. When it is deficient, cells become permeable and lose control over the import and export of nutrients, leading to tissue breakdown.

When calcium supply is inadequate or transport is disturbed, local calcium deficiencies will result. This can lead to membrane breakdown and/or cell wall failure; in fruit this can result in disorders such as blossom end rot. Whether this is actually the cause of such a disorder or whether calcium deficiency is a result of this condition has recently been debated.

Calcium (as the ion Ca²⁺) is also an intracellular secondary messenger involved in many signal transduction pathways in stone fruit trees. Its irreplaceable function in this role and in cell wall polysaccharide interactions is undisputed. It is through these processes that calcium is central to stress responses, cell wall growth and remodeling, and to plant tissue development. Since Ca2+ is such a biologically active ion, its concentration and transport must be tightly controlled within plant tissue down to the level of cellular and extracellular compartments.

Calcium has an impact on the interior quality of stone fruits, and fertilization may have a positive or negative effect on the availability of calcium and its uptake from the soil. Fertilization in calcium deficient soils is a necessity and is also very important in acidic soils.
Calcium can be very helpful to reduce the impact of high heat on flowers. Heat stress during flowering can lead to pollination failure. Severe heat stress will also result in increased bud drop. After successful pollination and fertilization, the ovaries develop into the fruit and the ovules develop into the seeds, two additional processes that each have specific chemical and nutritional requirements that a plant nutrition product specially formulated for application during pollination can provide.

In the fertilization of stone fruit trees, magnesium contributes to the absorption and migration of phosphorus, and it improves the capturing of iron in the fruit trees.

Its deficiency appears as chlorosis on the old leaves at the base of branches, which can fall prematurely and cause the appearance of secondary branches. Symptoms are more pronounced on leaves situated close to fruit clusters. Deficiency occurs by impairment, as well as by antagonism, with calcium and potassium. Magnesium deficiency can occur with light acidic soils that are prone to leaching or in soils that have received high rates of potassium fertilizers.

Each litre of Thio-Sul provides approximately 160 g of nitrogen and 346 g of sulfur, delivering a concentrated and efficient source of both nutrients. Its liquid formulation is easy to handle and integrates readily into modern crop nutrition programmes across a wide range of crops and production systems.

By supplying nitrogen and thiosulfate sulfur together, Thio-Sul helps maintain an appropriate nitrogen-to-sulfur balance, supports protein formation and promotes more efficient use of applied nitrogen. Its sulfur becomes available progressively as thiosulfate is converted in the soil, helping support crop nutrition throughout key growth stages.

Thio-Sul can be applied through irrigation systems, banded, broadcast, injected into the soil or incorporated into compatible liquid fertiliser blends. This application flexibility makes it a practical solution for improving sulfur nutrition and complementing nitrogen fertilisation.

Each litre of KTS supplies approximately 360 g of potash and 252 g of sulfur, providing a highly concentrated source of soluble potassium and sulfur. Its nitrate-free and chloride-free formulation allows potassium to be supplied without adding unnecessary nitrogen or chloride.

Potassium supports water regulation, enzyme activity, carbohydrate transport and the development of crop yield and quality, while sulfur contributes to protein and enzyme formation. KTS is particularly valuable during periods of rapid growth, reproductive development and crop filling, when potassium requirements can increase substantially.

KTS can be used through fertigation, in starter or side-dress programmes, in compatible liquid fertiliser blends and as a foliar treatment on selected crops. Its versatility allows potassium and sulfur to be delivered at critical stages within a wide range of crop nutrition programmes.

Each litre of CaTs supplies approximately 75 g of calcium and 125 g of sulfur, providing both nutrients in a fully soluble liquid form. CaTs combines crop nutrition with soil-management benefits and can be incorporated into a broad range of fertilisation programmes.

Calcium contributes to cell-wall strength, root development and the structural integrity of growing plant tissues, while sulfur supports protein and enzyme formation. A consistent calcium supply is especially important during periods of rapid vegetative growth and fruit development, helping support crop quality, firmness and marketability.

CaTs can be applied through irrigation systems, banded, broadcast or blended with compatible liquid fertilisers. It may also be used as a soil amendment to provide soluble calcium, support soil aggregation and water infiltration, and help manage the effects of excess sodium in saline or sodic soils.

Its fine crystalline formulation dissolves rapidly and completely, producing a clean spray solution with minimal residue. This makes K-Leaf particularly suitable for precision spraying and for situations in which crops require a rapid supplementary supply of potassium and sulfur.

Applied directly to the foliage, K-Leaf helps prevent or correct potassium and sulfur deficiencies during critical growth stages. Potassium supports water regulation, photosynthesis, carbohydrate movement and crop quality, while sulfur contributes to protein synthesis and essential metabolic processes.

K-Leaf can supplement soil fertilisation when nutrient uptake through the roots is restricted or when crop demand temporarily exceeds soil supply. It is suitable for a wide range of broad-acre, fruit and vegetable crops and can be combined with many compatible soluble fertilisers and crop-protection products following a compatibility test.

SoluPotasse provides potassium and sulfur without nitrogen or chloride, allowing both nutrients to be managed independently within the crop nutrition programme. Its fine crystalline form dissolves rapidly and completely, making it suitable for demanding fertigation applications.

Potassium supports water-use regulation, enzyme activation, carbohydrate transport and crop quality, while sulfur contributes to protein formation and nutrient metabolism. SoluPotasse is particularly useful when crops require additional potassium but no further nitrogen, including during fruit, tuber and grain development.

SoluPotasse can be applied through fertigation and other systems designed for fully soluble fertilisers. Its low-chloride, nitrogen-free composition makes it well suited to chloride-sensitive crops, saline growing conditions and fertilisation programmes requiring precise control of nitrogen and potassium inputs.

The chloride-free, nitrogen-free formulation of GranuPotasse provides an efficient source of potassium and sulfur, making it ideal for chloride-sensitive crops and high-value production systems. The uniform, free-flowing granules ensure accurate spreading, easy handling and consistent field performance.

By supplying potassium and sulfur in readily available forms, GranuPotasse supports water regulation, enzyme activation, carbohydrate transport and protein synthesis, helping improve crop yield, quality and marketability. It is particularly beneficial for fruit, vegetable and other high-value crops where crop quality, storage life and export potential are essential.

GranuPotasse® is suitable for pre-plant, basal and in-season applications and can be broadcast, banded or incorporated into the soil. It also blends readily with many granular fertilizers, providing growers with a flexible solution for balanced potassium and sulfur nutrition across a wide range of cropping systems.