Spring is a time of anticipation for bountiful harvests, both for farm owners and small garden plots. During this period, the potential yield for many berry crops, particularly for garden strawberries, is being formed. The vegetation period of strawberries is characterized by numerous questions of general technological and seasonal nature.
Seasonal Peculiarities: Resumption of Vegetation after Winter Period.
After a prolonged wintering, the plant lacks a sufficient amount of carbohydrates for Nitrogen assimilation. Therefore, before applying nitrogen fertilizers in spring, it is crucial to focus on regenerating the root system, using phosphorus fertilizers and biostimulants containing auxin.
Phosphorus fertilizers are applied both when preparing the soil before planting the plants in their permanent location and in the fertigation system at the initial stages of development.
However, it’s important to remember about the temperature limitations of Phosphorus uptake by the root system – from 14°C.
Therefore, in the early spring period, it is advisable to concentrate on foliar feeding. Optimal phosphorus nutrition stimulates all processes associated with flower fertilization, fruit setting, formation, and ripening. Excess phosphorus leads to premature wilting of the leaf apparatus and early ripening of fruits, resulting in plants not having enough time to yield a sufficient harvest. Phosphorus deficiency manifests in delayed growth and development of plants: small leaves form, flowering and fruit ripening are delayed.
And what about biostimulants? Here, of course, preparations with a high concentration of auxins will help us.
Without the hormone auxin, almost nothing happens in the plant organism. From the very first days, the plant embryo cannot do without auxin. Auxin is synthesized at the growth point of the shoot, influences the movement of photosynthesis products through the phloem, stimulating the development of the root system, and subsequently, the fruits. Therefore, it is extremely important to timely provide the plant with a “ready-made cocktail” of biologically active substances, additionally enriched with a complex of macro- and microelements. And here, Novalon Seed Treatment comes to our aid – an effective tool in vegetation recovery. Only 1 kg/ha per drop, and excellent results are achieved thanks to a balanced composition: N-P-K + microelements + amino acids + growth hormone (auxins/cytokinins) + humic and fulvic acids. Foliar application is best carried out with Speedfol Amino Starter – a highly concentrated fertilizer with an emphasis on Phosphorus and auxins. To conclude the fertigation system, it’s better to use simple water-soluble fertilizer Hydroponica MKP – a balanced combination of Phosphorus and Potassium for vegetation recovery in strawberries.
Seasonal Features: Blooming.
Approximately 2-2.5 weeks after the start of vegetation, the growth of flower-bearing shoots is completed, and as the temperature accumulates (above +5°C), flowering begins. Although there is a time reserve for berry ripening of 20-30 days, its quality depends on nutrition during the flowering period. The uniform surface of garden strawberries and its shape depend directly on two interconnected factors: pollination and an adequate amount of Boron. Regarding pollination, during the active flowering period, 5-8 beehives are used per hectare (depending on varietal characteristics) with bumblebee families.
Among all microelements, Boron has the strongest influence on harvest quality. Symptoms of Boron deficiency occur when the leaf contains less than 4 mg of this element per 1 kg of dry weight.
Boron cannot be reutilized since it does not transfer from old plant organs to young ones. In plants experiencing a Boron deficiency, poor differentiation and death of meristematic cells occur, development is disrupted (vessels are distorted and compressed), and the conductive system degrades – water and mineral nutrient transport to growing cells is disrupted.
Due to the strong sorption of Boron in the soil, standard application of boron fertilizers may not yield the desired result. To prevent Boron deficiency, in addition to systematic use of Boron-containing fertilizers, it is necessary to regulate the dose of meliorant during soil liming, as Calcium is the most important antagonist of Boron. Moreover, an effective tool for preventing excessive application of Boron-containing fertilizers in the soil is foliar feeding, implemented by applying Powerfol Speedfol B in combination with the mineral nutrition corrector Speedfol Amino Flower&Fruit – thanks to the high concentration of auxins in combination with Boron, active pollination will be ensured.
It is precisely during the flowering period that the selection of plant samples for determining the deficiency of macro- and microelements using laboratory analysis of plant tissue is relevant, with the aim of further adjusting nutrition.
Seasonal Features: Possible Stresses and How to Combat Their Effects.
Despite the fact that garden strawberries are resistant to low temperatures, late frosts can significantly damage the flowers. How can we reduce the risk of late frosts affecting garden strawberries in open ground? One way to address this issue is to use growth biostimulants with a high potassium content, which enhance the formation of cellulose and pectin substances, increasing the thickness of cell walls, thereby strengthening tissues and minimizing the destructive impact of external factors. Application algorithm: one week before the frosts, use Speedfol Marine or Powerfol Undaria – biostimulants with a high concentration of hormones and bioactive substances, along with potassium and boron. It will also be beneficial to provide comprehensive nutrition with Novalon Foliar 9-12-40, which contains a balanced combination of macro, meso, and microelements, in combination with a biostimulant.
During plant stress, the synthesis of amino acids is inhibited, leading to a slowdown in protective and physiological processes within the cell and resulting in reduced harvest. After late frosts, it is necessary to use anti-stress preparations with a high content of L-amino acids. Proteins are synthesized from these amino acids, which in turn form simple enzymes and enzymatic complexes that determine the plant’s resistance to stressful conditions during vegetation and its ability to overcome their consequences. Additionally, some L-amino acids simultaneously serve as building material for the formation of cell walls in plants. To provide the plant with the necessary set of L-amino acids, anti-stressants like Speedfol Amino Calmag can be used.
Seasonal Features: Balanced Calcium Nutrition.
To obtain a tasty and transportable harvest, it is essential to ensure that garden strawberries receive adequate calcium. The application of calcium-containing fertilizers is primarily aimed at preventing the occurrence of physiological disorders. However, it is important to remember that the structural integrity of stems, which support flowers and fruits, as well as the firmness of the fruits and their storage period, largely depend on the presence of calcium. The majority of calcium is absorbed at the beginning of the vegetative period. Depletion of calcium in the fruit pulp is caused by a decrease in transpiration. When calcium nutrition is disrupted, physiologically induced secondary reactions occur as a result of an imbalance between calcium and other nutrient elements. It is important to consider the antagonism of calcium with magnesium and potassium.
Calcium nitrate, or Hydroponica Calcium Nitrate, is an ideal source of calcium for fertigation systems. Nitrate nitrogen ensures the absorption of cations not only of calcium but also of potassium and magnesium from the soil solution.
An effective and fast tool for improving the firmness and transportability of berries is the application of calcium via foliar feeding from the beginning of fruit set to ripening. A mono-element fertilizer like Powerfol Calcium with a calcium content of 221.4 g/l is an excellent tool for foliar application during the fruit development and ripening phase.
pH Requirements for Soil Solution.
The ideal pH range for growing garden strawberries is from 5.5 to 6, although a slightly broader pH range of 5 to 7 units can also be acceptable.
When the soil pH drops below 5, the availability of essential compounds like Magnesium, Calcium, Phosphorus, and Molybdenum decreases. At a pH above 7, plants face difficulties in absorbing Zinc, Manganese, and Iron. Visual symptoms of limited absorption include various forms of chlorosis.
The pH level can be improved by timely application of lime or chalk if dealing with overly acidic soil. Lime should be applied in the autumn of the preceding year for spring planting, or in early spring if planting is scheduled for the autumn.
To lower the pH in the year of harvest, the use of acidifying fertilizers can be helpful. Specifically, by using complex fertilizers with microelements like those in the Novalon series (with a pH of 4.76-2.79 for a 1% solution), Nutriflex S (pH of a 1% solution is 5.25), or Hydroponica UP (pH of a 1% solution is 2) in the fertigation system.
Requirements for Soil Solution Salt Concentration and Nutrient Solution.
Strawberries are one of the most sensitive crops to salinity. The electrical conductivity of the nutrient solution should be between 0.8-1.6 mS/cm, and for the soil, it should be 0.6-1.0 mS/cm, depending on the soil type, variety, and climatic conditions.
The level of salt concentration in the root zone is directly related to the quality of water, the fertilizer application rate, and the depth of irrigation. General salinity stress occurs when salts accumulate in the soil solution to a level where the plant can no longer access sufficient water from the soil during growth. Osmotic stress caused by salt loading leads to osmotic dehydration, rapidly lowering cell water potential and reducing all vegetative and reproductive parameters, ultimately resulting in yield reduction ranging from 10 to 60%.
Visually, moderate salinity issues can be identified by a reduction in plant size and color changes, either in spots or uniformly across the field: a slight alteration in leaf color, with plants becoming slightly darker and bluish-green. Over time, slowed plant growth becomes evident, and eventually, leaf tips and edges start to burn. Yield losses due to salinity-related issues begin long before symptoms are visually apparent.
In simple terms: when the soil salinity level reaches 3 g/L, it’s necessary to apply gypsum to the soil. In the year of harvest, high salt content is managed by flushing, using 10-20% more irrigation water than usual. The amount and frequency of irrigation should be adjusted to ensure sufficient leaching while minimizing the risk of excessive soil moisture.
Low electrical conductivity negatively affects the strawberry yield. Low solution concentration in the root zone leads to softer skin and shorter storage life, and can cause fruit cracking with excessive watering. To address this issue, it’s important to regulate the EC level of irrigation water according to the stage of development and variety of the strawberry.
That’s why special attention should be given to the selection of crystalline fertilizers for fertigation. Water-soluble fertilizers like those from the Nutriflex and Novalon lines are known for their optimal indicators, suitable for use in fertigation with EC levels of 1.32 and 0.92 respectively.
By reaching out to TerraTarsa experts, you’ll find support at every stage of plant development.
Onward to abundant harvests!