Most raspberry varieties require 3 years from planting to achieve maturity and full production potential. This crop can remain productive for 8-12 years. However, by the end of this time, viral diseases accumulate in the plant and limit its lifespan. It is in the interest of growers to periodically replace plantings to achieve maximum productivity.

Raspberry is relatively tolerant to soil, but grows best in well-drained loamy soils.

Factors limiting the growth and development of raspberry plantations:

1. High groundwater levels.
2. Compacted soil.

Raspberry roots are usually found in the top 60 cm of soil. Therefore, the level of groundwater should not exceed 1 m from the soil surface for more than a few days.

Poor drainage can cause root rot, which can lead to severe winter damage and growth suppression with subsequent plant death. An alternative may be to establish raspberry plantations on raised beds. This agricultural technique reduces the likelihood of root rot, but in the future, raspberry plantations will require more water than those on flat ground. Balanced irrigation is extremely important during the period of active shoot growth from May to August.

Restoration of vegetation in the spring

Stable development of raspberry plantations in the spring determines the fruiting of the current year. Moderate temperatures and the absence of frost are acceptable for the start of raspberry growth in the spring. Young vegetative shoots are vulnerable to frost of -8°C. Raspberry plants are also sensitive to late frosts below -5°C. If there are temperature fluctuations, the biostimulator Speedfol Marine based on seaweed extract may come in handy. The bioactive cocktail (phytohormones, polyamines, polysaccharides, etc.) combined with Phosphorus, Potassium, Boron, and Zinc will help the plant better prepare for possible stress if we work on prevention 5-7 days before the sudden temperature drop. If no temperature drop is observed subsequently, for recovery after stress, attention should be paid to Speedfol Amino Calmag. In the fight against stressful factors (in this case, the aftermath of turning frosts), amino acids are synthesized by plant cells for protein building and, subsequently, rapid recovery. Understanding this mechanism, it is expedient to use non-root products with L-amino acids that store energy and, essentially, rebuild and restore the plant. Speedfol Amino Calmag contains 18 L-amino acids, Calcium, and Magnesium, which are essential for strengthening the cell wall and respiratory processes of the plant cell.

Phosphorus and its importance

Phosphorus is a lever for launching vegetative recovery in the spring. Phosphorus enters the root system and functions in the plant in the form of oxidized compounds, mainly residues of orthophosphoric acid (H2PO4-, HPO42-, PO43-). When phosphoric acid enters the living cells of the roots, it quickly becomes a part of nucleotides, and then, in the process of phosphorylation (anaerobic and aerobic phases of respiration), ATP is formed, which is used to activate sugars, amino acids, synthesize nucleic acids, proteins, and other processes. In the soil, phosphorus is found in a slightly soluble form, so the metabolism of roots plays a significant role in providing plants with phosphorus. Inorganic fertilizers provide an available form of phosphorus for plants, unlike the main mass of phosphorus in the soil. Therefore, fertilization should begin with a complex fertilizer-stimulator Novalon Seed Treatment, which is a source of macro-, meso-, microelements, phytohormones, humic and L-amino acids, in combination with water-soluble crystalline fertilizers Novalon 13-40-13+ME and Hydroponica MKP (monopotassium phosphate).

When choosing organic materials as a source of phosphorus, it is important to remember that the use of manure and compost on heavy soils increases the water-holding properties of the soil, which can negatively affect the oxygen regime, root development, and subsequently, the growth, development, and fruiting of the raspberry plantation.

Nitrogen for raspberry

Nitrogen requirements vary depending on yield, shoot growth, plant age, soil type, irrigation, rainfall, and variety.

Less nitrogen is needed in the year of planting compared to subsequent years. Excess nitrogen has a negative impact on yield, fruit quality, and transportability. In addition, excess nitrogen promotes intense vegetative growth, manifested in the elongation of shoots and an increase in the distance between nodes, thus reducing the yield from a single shoot. Nitrogen fertilization should be based on nitrogen concentration in tissues, yield, and irrigation. The nitrogen concentration in tissues at the end of July or early August should be between 2.3% and 3% of the total weight. For summer varieties of raspberries, the amount of nitrogen fertilizer needed should be divided into two applications: the first during early spring vegetation, and the second one month before the appearance of green-colored berries. This scheme will ensure the quality of the fruit in the current year and a large harvest the following year by promoting vegetative shoots of the current year (suckers).

Regarding raspberry remontant varieties, the Nitrogen norm should be divided into 3 parts: for application in early spring, a month before harvest, and with the onset of the first flowering.

Raspberry plants absorb Nitrogen in the nitrate form faster than in the ammonium form, but there is also a significant downside – nitrate is more easily washed out from the soil. Ammonium Nitrogen is bound to soil particles and is also converted into the nitrate form during the nitrification process. One of the factors that controls the nitrification process is the soil pH. Ammonium Nitrogen quickly transforms into nitrate in a warm, moist environment with a pH above 6.

Different fertilizers nitrify at different rates, especially at lower soil pH levels. All Nitrogen sources nitrify faster at a pH of 6.0 than at 5.5. The optimal pH for the growth and fruiting of raspberry plants is 6.0-6.5. The best way to supply Nitrogen to raspberry plantations according to their growth phase is to use fertigation with Hydroponica Calcium nitrate and Ultrasol K potassium nitrate, combined with complex fertilizers such as Nutriflex S, which contains both nitrate and ammonium forms of Nitrogen, with a predominance of nitrate.

Regarding potassium for raspberries

The amount of potassium to be applied before planting raspberries is determined by soil analysis. 50-75% of the available potassium should be applied during raspberry planting. Granular fertilizers with high content of macro- and microelements are ideal for this purpose. The remaining amount (25-50%) is applied through fertigation, combining complex water-soluble crystal micro-fertilizers such as Novalon 3-7-37+ME or Nutriflex S with simple salts such as Hydroponica MKP (monopotassium phosphate), Ultrasol K (potassium nitrate) and Hydroponica SOP (potassium sulfate).

Boron and its necessity

Insufficient supply of Boron to plants disrupts the formation of conducting tissues (phloem and xylem), resulting in difficulty in the movement of carbohydrates through vessels to growing organs. Additionally, Boron is involved in the formation of plant reproductive organs and is necessary for the normal process of fertilization. Inadequate Boron can lead to disruptions in the formation of reproductive organs and fruit set. Supplying Boron is extremely important during the flowering period and in preparation for the winter season (in the autumn). The effective use of Powerfol Boron, applied either through foliar or fertigation, at a rate of 0.5 L/ha is recommended. This product is certified by Organic Standard for use under organic farming conditions and is also effective for use in intensive farming technology.

Fruiting

Raspberry is unique in that during the period of berry ripening on the shoots that bear fruit in the current year, vegetative shoots from the root system also develop, leading to competition between shoots for carbohydrates and nutrients. There is a practice of removing the first and second vegetative shoots in order to distribute nutrients to the fruit-bearing shoots. In addition, this measure increases the number of fruits by increasing the amount of light to the generative buds. Light is a limiting factor for unlocking the maximum potential of raspberry fruiting. Speedfol Amino Flower & Fruit can help plants unleash their genetically determined yield potential. This product contains predominantly auxins in its hormonal composition, which participate in the process of bud and fruit formation, thereby accelerating the development and ripening of fruits. It also contains a complex of L-amino acids and balanced macro-, meso-, and microelements, tailored to the developmental phase. It is important to remember that during this period, sufficient nutrition with potassium and calcium is necessary for the formation of a high-quality harvest with excellent flavor characteristics. Foliar feeding should not be neglected either. The Novalon Foliar 9-12-40+ME + Powerfol Calcium + Speedfol Amino Calmag complex provides plants with potassium and calcium and helps alleviate stress thanks to the content of L-amino acids.

Preparing for the winter period

During the winter, cellular metabolism stops due to low temperatures. The cold period is necessary for the formation of generative buds. Excessive watering in the autumn period stimulates the growth of shoots in late autumn, and the plant is unable to enter a dormant state properly. To prepare the plant for this period, it is necessary to gradually reduce the amount of irrigation water starting from August, excluding nitrogen nutrition. The main macronutrients for fertilization during this period are phosphorus and potassium, and among micronutrients, boron and zinc. Zinc is part of various enzymes such as dehydrogenases, peptidases, and phosphohydrolases. The main functions of zinc in plants are the metabolism of carbohydrates, phosphates, and proteins, the synthesis of auxins, DNA, and ribosomes. In addition, zinc affects membrane permeability, stabilizes cellular components, increases plant resistance to dry and hot climates, fungal and bacterial diseases, and ensures the formation of healthy generative buds. The chelated form of zinc is contained in Powerfol Zn EDTA. To prepare the raspberry plantation for the winter period, it is sufficient to apply 1 liter per 1 hectare. In the post-harvest period, foliar feeding should also be supplemented with boron and macronutrients, with an emphasis on phosphorus and potassium. Therefore, the mix of Powerfol Zn EDTA + Powerfol Boron or Speedfol B + Novalon Foliar 10-45-15+ME will be the most effective solution.

For fertilization, Novalon 3-7-37+ME is used – a complex water-soluble fertilizer that contains macro, meso, and micronutrients, combined with Hydroponica MKP (monopotassium phosphate).

Potent additional nutrition options for raspberry plants during the vegetation period:

• Early spring vegetation: Speedfol Marine – with an optimal ratio of auxins and cytokinins to activate root formation.
• Vegetation: Novalon Foliar 20-20-20 +ME – already with surface-active substances that allow the fertilizer to be retained on the leaf even during bad weather.
• Powerfol Calcium + Speedfol Amino Calmag – a complex aimed at increasing crop transportability.
• Powerfol Zn EDTA + Powerfol Boron – micronutrients that provide a harvest for the following year.
• The concentration of the working solution (EC) should not undergo significant jumps – otherwise, this will negatively affect the current harvest.