Next Article in Journal
Adaptive Tracking and Cutting Control System for Tea Canopy: Design and Experimental Evaluation
Previous Article in Journal
Whole Genome Analysis of Proteus mirabilis in a Poultry Breeder Farm Reveals the Dissemination of blaNDM and blaCTX-M Mediated by Diverse Mobile Genetic Elements
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Agriculture
Volume 15
Issue 5
10.3390/agriculture15050556
agriculture-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

The Role of Foliar-Applied Silicon in Improving the Growth and Productivity of Early Potatoes

by
Wanda Wadas
* and
Tomasz Kondraciuk
Institute of Agriculture and Horticulture, Faculty of Agricultural Sciences, University of Siedlce, 14 B. Prusa, 08-110 Siedlce, Poland
*
Author to whom correspondence should be addressed.
Agriculture 2025, 15(5), 556; https://doi.org/10.3390/agriculture15050556
Submission received: 18 January 2025 / Revised: 2 March 2025 / Accepted: 4 March 2025 / Published: 5 March 2025
(This article belongs to the Special Issue The Role of Silicon in Improving Crop Growth Under Abiotic Stress)
Browse Figures
Versions Notes

Abstract

:
Climate change is leading to a decline in global potato production. To ensure food security, it is essential to adapt cultivation practices to the changing climate. The effects of foliar-applied silicon on potato growth and productivity under various hydrothermal conditions were investigated. Potato plants were treated with three Si-based biostimulants: Actisil (6 g of Si and 20 g of Ca per liter; choline-stabilized orthosilicic acid; Chol-sSa + Ca); Krzemix (6 g of Si per liter; choline-stabilized ammonium metasilicate; Chol-sNH4-Sil); and Optysil (93 g of Si and 24 g of Fe per liter; sodium metasilicate and iron chelate Fe-EDTA; Na-Sil + Fe-EDTA). Biostimulants were foliar-applied twice, at the leaf development stage (BBCH 13–15) and two weeks after the first treatment, at 0.5 L/ha in each treatment. The plants treated with biostimulants were taller and produced greater above-ground biomass and a higher tuber weight than the control plants (without a biostimulant). As a result, the total tuber yield was higher, on average, by 10% to 13% and the marketable tuber yield by 11% to 15%. The plant-growth-promoting and yield-increasing effects of the Si-based biostimulants depended on the hydrothermal conditions during potato growth. Chol-sSA + Ca (Actisil) applications were the most effective. Na-Sil + Fe-EDTA (Optysil) produced better results during a warm and very dry year, while Chol-sNH4-Sil (Krzemix) was effective during colder years with a periodic water deficit. Silicon foliar application can be a new method for increasing early crop potato yields under water shortage conditions.

1. Introduction

In recent years, the growth and productivity of crop plants have been greatly influenced by environmental stresses caused by global climate change. Periods of high temperatures and drought are becoming more frequent in central Europe, south-central Asia, south-eastern America, and the south-eastern United States [1]. Drought is one of the most serious factors impacting crop plant productivity. Drought stress disturbs plant–water relations, reduces the photosynthesis rate, and induces oxidative stress in plants. As a result, drought stress adversely affects plant growth and yields [2,3]. To ensure food security and sustainable development, it is necessary to adapt cultivation practices to global climate change and breed stress-tolerant cultivars.
The application of biostimulants is a low-input and environmentally friendly crop management tool [4,5,6]. In recent years, the use of some trace elements (I, Se, Si, Ti, and V) as biostimulants to improve plant tolerance to environmental stress has increased [7,8,9].
Silicon (Si) application has gained more attention. It has a potential role in mitigating environmental stresses in plants when properly employed [10,11,12,13,14,15]. Several studies have reported a multi-faceted role of silicon in mitigating abiotic stress in plants by regulating various physiological, biochemical, and molecular processes. Silicon can serve as a physical barrier and improves plant–water relations by regulating root water uptake and transpiration. It also boosts nutrient uptake, increases the rate of photosynthesis by increasing the content of photosynthetic pigments and the activity of photosynthetic-related enzymes, and regulates the biosynthesis of phytohormones. Moreover, silicon influences the activity of antioxidant enzymes and the expression of genes related to stress tolerance, ultimately helping to reduce oxidative stress in plants [10,11,12,13,16]. Silicon can be applied through foliar spraying, fertigation, or incorporation into the soil. Foliar application of silicon has a greater biostimulant effect than when it is applied to the soil [17]. The forms of silicon used for foliar application include silicates (sodium silicate, potassium silicate, calcium silicate, or ammonium silicate); stabilized orthosilicic acid; and silica nanoparticles. Potassium silicate and sodium silicate are the most commonly used silicon compound [11,18,19]. Stabilized silicates are a new form of silicon for foliar application in annual crops [20].
Silicon has been proven to mitigate drought stress in plants [21,22,23,24,25]. The beneficial effect of foliar-applied silicon on the productivity of crops, ensuring global food security (wheat, rice, and maize), has been reported. Silicon increased wheat yields by 10–27% [18,26,27], rice yields by 10–45% [28,29], and maize yields by 15–42% [20,30]. Monocotyledonous plants are higher silicon accumulators than dicotyledonous plants [19]. Our understanding of the effect of silicon on potato growth is currently limited. Most experiments have been carried out under controlled conditions in a greenhouse [31,32,33,34,35] and as a one-year field experiment under tropical and subtropical [36], moderate maritime [28], and arid and semi-arid [37,38] climate conditions. Potatoes are a staple food in many countries, and climate change has consequences for potato production [39]. Hijmans [40] predicts a decline in global potato production due to climate change by 18 to 32% over the period of 2040–2069, whereas Raymundo et al. [41] predict small global reductions in potato yields by 2055 (2–6%) and further reductions by 2085 (2–26%). The most significant negative effect of climate change on global potato yields is expected to occur toward the end of the century. The predicted impacts vary by region. Large reductions in potato yields are predicted in high latitudes (eastern Europe and northern America) and the African lowlands, with smaller reductions anticipated in the mid-latitudes and tropical highlands.
Potato is a relatively drought-sensitive crop. Even short periods of water deficits can reduce potato yields [42,43,44]. Heat stress can also seriously reduce potato yields. The effect of high temperature on potato growth depends on the plant growth stage, and earlier occurrences have a more negative impact on yields. Early-maturing potato cultivars are usually less affected by heat stress than late cultivars due to their short growing periods and shorter exposure to high summer temperatures [45,46,47]. Although potato is a low accumulator of silicon [48,49], foliar silicon application could improve potato growth and productivity. In tropical climates in Brazil, foliar-applied silicon (potassium silicate; stabilized silicic acid) increased the commercial potato yield by 14–40%. The yield-increasing effect of silicon depended on the potato cultivar, its location, and the form of silicon applied. Silicon also caused a higher increase in yields of a very early potato cultivar than a late cultivar [36,50]. In moderate maritime climates in the Netherlands, foliar-applied silicon (stabilized silicic acid) increased potato yields by 6.5% [28], whereas in arid climates in Iran, silicon (sodium silicate nanoparticles; silica) increased potato yields by 10–56%, depending on the severity of salinity stress [37]. In semi-humid climates in Kenya, silicon (orthosilicic acid) increased potato yields by 56% [51]. Previously, a study of temperate climates in Poland showed that foliar-applied silicon (orthosilicic acid) increased potato yields by 6.4–17.6%, depending on the number of treatments performed [52]. Another study in Poland showed that foliar-applied silicon (sodium silicate) increased the commercial yield of early potatoes by 8.6–50%, depending on the hydrothermal conditions during the potato growth [53].
The current study hypothesized that foliar-applied silicon will improve potato growth under unfavorable hydrothermal conditions, increasing the share of assimilation organs in the whole plant weight, the leaf area ratio and specific leaf area, and the chlorophyll content in leaves and, as a result, will increase the early crop potato yield. To test this hypothesis, the effects of Si-based biostimulants on the growth and yield of early potato cultivars were investigated. The novelty of this work is found in its contribution to the understanding of how the environmental conditions of the use of silicon preparations affect their effectiveness. Notably, stabilized ammonium silicate was utilized as one of the soluble silicon sources for the first time in this research.

2. Materials and Methods

2.1. Experimental Location and Plant Growth Conditions

The study was conducted in an experimental field of the University of Siedlce in Poland in central Europe (52°03′ N, 22°33′ E) in 2020–2022. This region is characterized by a temperate climate. The experiment was located on Haplic Luvisol, with a sandy loam texture [54], a low organic-matter content (1.41–1.69%), an acid–slightly acid reaction (pHKCl 5.3–5.7), a high content of assimilable phosphorus (93–116 mg P/kg of soil), and a medium content of potassium (98–124 mg K/kg of soil) and magnesium (3.6–4.6 mg Mg/kg of soil).
The hydrothermal conditions during the potato growth period varied (Figure 1). The first experimental year of 2020 was moderately warm, with periodic water deficits. The following year (2021) was warm and extremely dry, whereas 2022 was warm and very dry.

2.2. Experimental Design and Treatments

The field experiment was established as a split-plot design with three replications. The potato plants were treated with three Si-based biostimulants: Actisil (6 g of Si and 20 g of Ca per liter; choline-stabilized orthosilicic acid; Chol-sSA + Ca); Krzemix (6 g of Si per liter; choline-stabilized ammonium metasilicate; Chol-sNH4-Sil); and Optysil (93 g of Si and 24 g of Fe per liter; sodium metasilicate and iron chelate; Fe-EDTA; Na-Sil + Fe-EDTA). Three early potato cultivars, Bohun (drought sensitive), Gwiazda (drought tolerant), and Lawenda (short-term drought tolerant) [55], were grown. These are new Polish edible potato cultivars in the multi-purpose cooking type (B). The Si-based biostimulant treatment was randomly allocated in the main plots, and the potato cultivars were randomly placed in subplots. Biostimulants were foliar-applied twice, at the leaf development stage (BBCH 13–15) [56] and two weeks after the first treatment, at 0.5 L/ha in each treatment (the dosages recommended by manufacturers). Potato plants sprayed with water were a control treatment without a biostimulant.

2.3. Data Collection

Potato cultivation was carried out according to common agronomical practices. Six-week pre-sprouted seed potatoes were planted on 7 April 2020, 6 April 2021, and 14 April 2022, with an in-row spacing of 0.25 m and 0.675 m between rows. The plot area was 16.2 m2 (96 plants per plot).
At the tuber formation stage (BBCH 41–43) [56], the height, above-ground plant biomass, assimilation leaf area, and chlorophyll content in leaves (Soil Plant Analysis Development value (SPAD)), were determined. The measurements were made on four successive plants per plot. The leaf area was measured by the weight method [57], and the chlorophyll content in leaves (ChlSPAD) was estimated by the non-destructive method using a portable SPAD-502 chlorophyll meter (Minolta, Osaka, Japan). An indicator analysis of plant growth was performed. The leaf area index (LAI), specific leaf area (SLA), leaf area ratio (LAR), and leaf weight ratio (LWR) were calculated [58].
Potatoes were hand-harvested 75 days after planting (the third decade of June). The tuber number, weight per plant, and total and marketable early potato yields were determined. The tuber number and tuber weight per plant were determined on ten successive plants per plot, and the tuber yield per hectare (t/ha) was calculated based on the tuber yield from each plot. The marketable yield consisted of tubers with a diameter above 30 mm without external defects. Only a few tubers with greening and mechanical damage were observed; therefore, the proportion of such tubers in the yield was not measured. The tuber size in the yield and the relationship between tuber yields and potato-plant growth traits were determined.

2.4. Data Analysis

An analysis of variance (ANOVA) for a split-plot design (Si-based biostimulant × potato cultivar × year) was performed on the data obtained. The Fisher–Snedecor F-test was used to test the significance of sources of variability, and Tukey’s post hoc test (p ≤ 0.05) was used to determine the honest significant difference (HSD). Results are shown as means ± standard deviation (SD). A linear correlation was used to determine the relationship between the tuber yield and potato-plant growth traits.

3. Results

3.1. Plant Height and Above-Ground Biomass

The plants treated with Si-based biostimulants were taller and produced greater above-ground biomass than the control plants (Figure 2a). Biostimulants slightly affected the stem weight but increased the leaf weight. Actisil (Chol-sSA + Ca) and Optysil (Na-Sil + Fe-EDTA) caused a faster rate of plant growth than Krzemix (Chol-sNH4-Sil), especially in the years with lower air temperatures or water shortages at the beginning of the vegetative growth stage. Optysil (Na-Sil + Fe-EDTA) produced the best results during a moderately wet year, with the lowest air temperatures at the start of potato growth (2020). Following the application of Optysil, the stems were longer, on average, by 4.1 cm, with a comparable weight to the control plants, which suggests that the stems were thinner. In contrast, the average weight of the leaves was 42.3 g (16%) higher than that of the control plants. In a warmer and extremely dry year (2021), the Actisil (Chol-sSA + Ca) application was more practical. Following the application of Actisil, the plants were taller (on average by 4.9 cm), the average weight of the stems was higher (by 51.2 g), and the average weight of the leaves was also higher (by 39.2 g) compared with the control plants. As a result, the above-ground plant biomass was 23% higher than the control plants. Si-based biostimulants slightly affected potato growth during a warm and very dry year (2022).
Si-based biostimulants had a greater beneficial effect on the growth of the Bohun and Lawenda cultivars than the Gwiazda cultivar (Figure 2b). The differences were highest in 2020, with the lowest air temperature at the start of potato growth (data not presented).

3.2. Assimilation Area and Chlorophyll Content in Leaves

Si-based biostimulants caused an enlargement of the assimilation leaf area under water deficits (Figure 3a). In the moderately wet year with the lowest air temperature after plant emergence (2020), the Optysil (Na-Sil + Fe-EDTA)-treated plants had a larger leaf area, on average, by 776 cm2 (13%), than the control plants. In the warmer but extremely dry year (2021), the Actisil (Chol-sSA + Ca) application caused an enlargement of the leaf area, on average, by 966 cm2 (23%). Krzemix (Chol-sNH4-Sil) slightly affected the leaf area.
Si-based biostimulants had a significant effect on the assimilation leaf area only for the Bohun and Lawenda cultivars (Figure 3b). Regardless of the hydrothermal conditions, the greatest enlargement of the leaf area of the Bohun cultivar was caused by Actisil (Chol-sSA + Ca) and Lawenda by Optysil (Na-Sil + Fe-EDTA).
The biostimulants used in the present study did not affect the chlorophyll (ChlSPAD) content in leaves (Figure 3a,b). The ChlSPAD depended on the cultivar and hydrothermal conditions during potato growth. The ChlSPAD was higher for Bohun than for Gwiazda and Lawenda. Regardless of the cultivar and treatment, ChlSPAD was lowest in the moderately wet year, with the lowest air temperature in the vegetative plant growth stage (2020) (data not presented).

3.3. Indicator Analysis of Plant Growth

Si-based biostimulants increased the leaf area index (LAI) but did not affect the specific leaf area (SLA), leaf area ratio (LAR), or leaf weight ratio (LWR) (Figure 4a,b). The LAI for the treated plants was higher, on average, by 0.23 to 0.29, than the control plants. Regardless of the treatment, the average LAI value was higher for the Lawenda cultivar leaf type than for the Bohun and Gwiazda stem types (data not presented).
The SLA, LAR, and LWR depended more on the cultivar and its growth habit and hydrothermal conditions during the vegetative growth stage. The SLA was higher for the stem-type Bohun and Gwiazda cultivars, whereas the LAR and LWR were higher for the leaf-type Lawenda (Figure 4b). Regardless of the cultivar and treatment, the average LAI and LWR values were highest in the moderately wet year, with the lowest air temperature during the vegetative plant growth stage (2020). In contrast, the SLA and LAR were highest in a warm and very dry year (2022) (data not presented).

3.4. Tuber Yield and Marketable Yield Components

The Si-based biostimulants did not affect the number of tubers formed per plant but caused an increase in the tuber weight (Figure 5a). As a result, the total tuber yield was higher, on average, by 1.69 t/ha to 2.09 t/ha (10% to 13%), as was the marketable yield, by 1.51 t/ha to 2.18 t/ha (11% to 15%), compared with the cultivation without a biostimulant (Figure 6a). Actisil (Chol-sSA + Ca) and Optysil (Na-Sil + Fe-EDTA) were more effective during a warm and very dry year (2022). In a colder year with a periodic water deficit (2020), the application of Actisil (Chol-sSA + Ca) or Krzemix (Chol-sNH4-Sil) produced better results. Actisil (Chol-sSA + Ca) was the most effective. Chol-sSA + Ca (Actisil) increased the marketable yield, on average, by 2.10 t/ha (18%) in a warm and very dry year (2022) and by 3.49 t/ha (16%) in a colder year, with a periodic water deficit during the tuber bulking stage (2020).
The Si-based biostimulants caused a higher yield increase for the Bohun and Lawenda cultivars, which are more sensitive to a water deficit than the Gwiazda cultivar (Figure 5b and Figure 6b). The differences were highest in 2020, with a periodic water deficit during the tuber bulking stage (data not presented).
Regardless of the cultivar and treatment, the main weight of the potato yield was made up of small tubers (with a diameter of 30–40 mm) (Figure 7a,b). Foliar-applied silicon caused an increase in the share of medium-sized tubers (with a diameter of 41–50 mm), and large tubers (with a diameter above 50 mm).
The tuber yield had a strongly positive correlation with the LAR, LWR, and tuber number and tuber weight per plant. A significant negative correlation was found between the tuber yield and plant height and stem weight under water deficits during potato growth (Table 1). A positive correlation was also found between the tuber yield and leaf weight and a negative correlation between the tuber yield and ChlSPAD in the year with the lowest air temperature after plant emergence and periodic water deficits.
Regardless of treatment, the tuber yield had a significant positive correlation with the leaf weight and leaf area, LAI, ChlSPAD, and tuber number and tuber weight per plant (Table 2). The correlation between the tuber yield and leaf area and LAI for control plants was stronger than for the plants treated with Si-based biostimulants. A stronger correlation was also found between the tuber yield and ChlSPAD for the control plants and the plants treated with Actisil (Chol-sSA + Ca) than for the plants treated with Krzemix (Chol-sNH4-Sil) and Optysil (Na-Sil + Fe-EDTA). A significant positive correlation was found between the tuber yield and LWR, following the application of Actisil and Krzemix.

4. Discussion

Periods of high temperature and drought are becoming more frequent in the temperate zone [1]. A soil water deficit is the limiting factor for potato growth and tuber yields. The time of occurrence and the duration and severity of the water deficit level affect the potato canopy growth. The early water shortage delays the canopy development by reducing the growth of shoots, i.e., the length and thickness of stems, the number and size of leaves, and the shoot weight. A longer water deficit duration slightly affects the final plant height but significantly reduces plant biomass [23,42,44]. Foliar application of silicon can improve potato growth under a water deficit [33,34,59]. Foliar-applied silicon can alleviate the water-deficit stress of potato plants by regulating physiological and biochemical processes. It can improve water relations and photosynthesis, reduce oxidative stress by increasing the activity of antioxidant enzymes (CAT and SOD), increase proline concentrations, and decrease hydrogen peroxide (H2O2) concentrations in plants [33].
The plant-growth-promoting effect of silicon depends on the form in which it is applied [18,27,34,60]. In the present study, Chol-sSA + Ca (Actisil) and Na-Sil + Fe-EDTA (Optysil) caused a faster rate of potato growth than Chol-sNH4-Sil (Krzemix). A previous Polish study showed that Na-Sil + Fe-EDTA (Optysil) improved the growth of the drought-sensitive very early cultivar Catania [59]. A field experiment in Brazil did not show any effect of orthosilicic acid (OSA) on the growth of the drought-tolerant early cultivar Cupido [61], whereas a greenhouse pot experiment in Iran did not show any effect of sodium silicate (Na-Sil) on the growth of the drought-tolerant late cultivar Agria [34]. Laane [18,28]) reported that foliar-applied stabilized silicic acid (sSA) promotes plant growth more effectively than silicates. In the present study, the plant-growth-promoting effect of Chol-sSA + Ca in Actisil was similar to the effect of a fifteen-fold higher dose of silicon in the form of Na-Sil + Fe-EDTA in Optysil. Silicon taken up by the root is translocated to the aerial plant parts through the xylem and is deposited as phytoliths in plant tissues in the apoplast. Soluble forms of silicon are available to plant roots at a concentration of 0.01–2.0 mM, depending on the soil type and pH. At concentrations exceeding 2.0 mM, silicon polymerizes to amorphous silicon, inducing stress in plants [11,19]. Silicon uptake by leaves and its translocation in plant cells is not well understood. Until now, there are no reports on the mechanism of silicon uptake by the leaf surface and silicon transporters in leaves [11,15]. Foliar silicon application has been proven to be effective only at a very low dosage [28,31]. Foliar-applied silicic acid is a better silicon source than silicates, because it is the direct source of plant-available silicon. For most crops, the recommended concentration of foliar-applied silicic acid ranges from 2 to 4 mL per liter of water. At high silicon concentrations, to prevent silicon polymerization in plant tissue, silicic acid is usually stabilized with choline or polyethylene glycol [15,19]. Stabilized silicates are a new form of silicon for foliar application in annual crops [20]. In the present study, the Na-Sil in Optysil was applied in a mixture with Fe-EDTA. Iron is a constituent of antioxidant enzymes (APX, CAT, POD, and Fe-SOD). Foliar-applied iron increases the activity of antioxidant enzymes and enhances the reactive oxygen species (ROS) scavenging system for alleviating abiotic stress in plants [62]. On the other hand, the Chol-sSA in Actisil was applied in a mixture with Ca, which also plays an important role in alleviating abiotic stress in plants [63]. The present study used mineral compounds other than silicon, making it difficult to conclude whether the effects were related to different forms of silicon treatments or to other minerals.
The cultivar differences in potato’s response to silicon observed by Dorneles et al. [31] were confirmed in the present study. The Si-based biostimulants had a greater beneficial effect on the growth of the Bohun and Lawenda cultivars, which are more sensitive to a water deficit than the Gwiazda cultivar. Potato cultivars display different mechanisms of tolerance to a soil water deficit. Potato root tips produce abscisic acid (ABA) in response to decreased soil moisture. ABA is involved in root-to-shoot drought stress signaling and is an important regulator of stomatal conductance [64]. The higher water use efficiency by the Gwiazda cultivar can be related to early stomatal closure due to its sensitivity to abscisic acid (ABA) and reduction in transpiration rates, with unhanged photochemical efficiency of PSII and photosynthesis [65]. Silicon treatment reduces ABA levels and the expression of ABA-related genes, which may contribute to alleviating drought stress in plants [66].
The Si-based biostimulants caused an enlargement of the assimilation leaf area under water deficit conditions but did not affect the chlorophyll content in leaves measured using a SPAD meter (ChlSPAD). Enlarging the leaf area does not always increase the tuber yield. The rate of photosynthesis per unit of leaf area decreases with an increase in the leaf area [58,67]. The SPAD index, also called the leaf greenness index, is a proxy for the chlorophyll content in leaves [68]. A previous study in Poland, in which an analytical method was used to determine the chlorophyll content, showed that Na-Sil + Fe-EDTA (Optysil) caused both an enlargement of the assimilation leaf area and an increase in photosynthetic pigment contents (chlorophyll a, chlorophyll b, and carotenoids) in leaves of the drought-sensitive, very early cultivar Catania [69]. The increase in chlorophyll content in leaves following silicon application under water deficit conditions could be associated with the protective role of silicon on the ultrastructure of chloroplasts or with increased activities of some antioxidant enzymes (CAT and SOD) located in chloroplasts that prevent chlorophyll degradation [33,70]. In the present study, the Na-Sil in Optysil was applied in a mixture with Fe-EDTA. Foliar-applied iron increased the chlorophyll content of potato leaves [71]. On the other hand, several studies reported the toxic effect of silicon at high concentrations on plants, resulting in physiological disorders, such as damaged chlorophyll biosynthesis and chlorosis [19].
In contrast, a greenhouse pot experiment in Brazil showed that polyethylene glycol-stabilized silicic acid (PEG-sSA) caused an enlargement of the assimilation leaf area and increased photosynthetic pigment (chlorophyll a and carotenoids) contents in the leaves of the early potato cultivar Agata, short-term and drought-tolerant, even in the absence of water stress [72]. In the present study, choline-stabilized silicic acid (Chol-sSA + Ca) did not affect the ChlSPAD of the tested, very early potato cultivars under a water deficit in an open field. A field experiment in Iran showed that foliar-applied silica (SiO2) or sodium silicate nanoparticles (Nano-NaSil) did not affect the chlorophyll a and chlorophyll b content in the leaves of medium late cultivar Agria under salinity stress. In contrast, Nano-NaSil increased the chlorophyll a and chlorophyll b content under non-stress conditions but did not affect the chlorophyll a/chlorophyll b ratio [37].
The Soil Plant Analysis Development index (ChlSPAD) relates to potato drought tolerance. An increase in ChlSPAD was observed under water deficit conditions, which indicated the stay-green effect in some potato cultivars. A higher increase in ChlSPAD was found for the more drought-sensitive cultivars [73,74] and was confirmed in the present study. Although the chlorophyll content in leaves may indicate a potato tuber yield under a water shortage, a higher ChlSPAD value does not always guarantee a higher yield. During plant senescence, chlorophyll increments could be associated with the occurrence of oxidative stress and could reduce tuber yields [73].
The LAI describes the growth in lowland fields, and the SLA, LAR, and LWR characterize the growth of individual plants. These indicators are determined by the potato cultivar and plant growth stage but may be modified by weather conditions and agricultural practices [75,76]. In the present study, the Si-based biostimulants increased the LAI but did not affect the SLA, LAR, or LWR. The LAI values for the treated plants were above 3, which is presumed to be optimal due to the highest radiation use efficiency [77]. The SLA, LAR, and LWR depended more on the cultivar and its growth habit and hydrothermal conditions during the vegetative growth stage. The LAI, LAR, and LWR were higher for the leaf-type Lawenda cultivar, whereas the SLA was higher for the stem-type Bohun and Gwiazda cultivars. Indicators of potato growth depend on the canopy structure. Cultivars characterized by a leaf type produced lower shoot biomass than those with a stem type. The detrimental effect of drought on light interception is greater for leaf-type than stem-type cultivars [78]. Previous Polish studies also did not find an effect of Na-Sil + Fe-EDTA (Optysil) on the SLA or LWR for the drought-sensitive, very early cultivar Catania, although a decrease in the LAR was observed [59,69]. Other researchers have demonstrated that silicic acid (OSA), found in the commercial product Silamol, enhances the LWR, which indicates the proportion of assimilating organs in the whole plant. This effect was observed in the very early cultivar Agata (short-term and drought-tolerant) under greenhouse conditions [72]. These results were obtained in a greenhouse pot experiment and cannot be extrapolated to the uncontrolled conditions of an open field. Potatoes are sensitive to changes in hydrothermal conditions during plant growth and may respond by falling or growing new leaves [66]. The early foliar expansion of potatoes is associated with an increase in SLA, whereas LAR and LWR decrease with plant growth, with LWR decreasing faster than LAR [75].
There is insufficient knowledge of the effect of foliar-applied silicon on potato yields. To date, nearly all experiments have been carried out under controlled conditions in a greenhouse or during only one growing season in an open field. A one-year field experiment in Brazil showed that potassium silicate (K-Sil) application could increase the marketable yield of the late cultivar Atlantic (drought sensitive) by up to 22% [50]. In contrast, sSA increased the marketable yield of the very early cultivar Agata (short term and drought tolerant) by 40% and the late cultivar Atlantic by 14% [36], which indicated the dependence of the yield-forming effect of silicon on the form in which it was applied. Laane [28] reported that polyethylene glycol-stabilized silicic acid (PEG-sSA) could increase potato yields by 20%. In the present study, Si-based biostimulants caused an increase in the total tuber yield by 10% to 13% and the marketable yield by 11% to 15%. Chol-sSA + Ca (Actisil) and Na-Sil + Fe-EDTA (Optysil) were more effective in a warm and very dry year. In a colder year with a periodic water deficit, the application of Chol-sSA + Ca (Actisil) or Chol-sNH4-Sil (Krzemix) produced better results. It is interesting that the yield-increasing effect of Chol-sSA + Ca (Actisil) under water stress conditions was similar to the higher dose of silicon in Na-Sil + Fe-EDTA (Optysil). In contrast, in the year with a periodic water deficit during the tuber bulking stage, the yield-increasing effect of Chol-sSA + Ca (Actisil) was similar to Chol-sNH4-Sil (Krzemix) with the same dose of silicon. As mentioned earlier, this study used mineral compounds other than silicon, making it difficult to conclude whether the yield-increasing effects were related to the silicon treatment itself and the form in which it was applied or to other minerals. The yield-increasing effect of the Si-based biostimulants depended on the potato cultivar. The yield increase of the more drought-sensitive cultivars (Bohun and Lawenda) was higher than that of the drought-tolerant cultivar (Gwiazda). These results confirm a genotypic difference in the potato response to silicon [31]. In a previous Polish study, OSA, in the commercial product Krzemian, caused an increase in the total tuber yield of the medium early cultivar Oberon (drought tolerant) by 6–18% [52]. Another study in Poland showed that Na-Sil + Fe-EDTA (Optysil) increased the marketable yield of the very early cultivar Catania (drought sensitive) by 50% under periodic water deficits during the tuber bulking stage and by 9% under drought conditions [53].
In early potato production, an even lower yield of larger-sized tubers produces a higher marketable value than the higher yield of smaller tubers. The Si-based biostimulants caused an increase in the early crop potato yield and improved its marketable value by increasing the share of medium-sized tubers (diameter of 41–50 mm) and large-sized tubers (diameter above 50 mm). Previously, an increase in the share of large tubers in the yield of the late cultivar Oberon and a decrease in the tendency to deform tubers following the application of OSA (Krzemian) were also found [52].
Potato yields have been proven to be positively correlated with the plant height, number of stems, and leaf area [79]. Enlarging the leaf area could enhance the export of assimilates and cause an increase in the tuber weight [44]. According to other authors, enlarging the leaf area does not always increase the tuber yield [58,67]. The tuber growth rate is only slightly correlated with LAI and still less so with SLA [80]. In the present study, regardless of hydrothermal conditions, the early crop potato yield was positively correlated with the LAR, LWR, and tuber number and tuber weight per plant. Under water deficit conditions, the tuber yield was negatively correlated with the plant height and stem weight. In the year with the lowest air temperature after plant emergence and periodic water deficits, a negative correlation was also found between the tuber yield and ChlSPAD, which could be associated with oxidative stress [73]. The tuber yield was positively correlated with the leaf weight and area, LAI, ChlSPAD, and tuber number and tuber weight per plant, both in the cultivations with and without Si-based biostimulants. A stronger correlation between the tuber yield and the leaf area and LAI was found for the control plants. The tuber yield had a stronger correlation with ChlSPAD following the application of stabilized forms of silicon Chol-sSA + Ca (Actisil) and Chol-sNH4-Sil (Krzemix) than Na-Sil + Fe-EDTA (Optysil). A positive correlation between the tuber yield and the LWR was found only for the plants treated with Chol-sSA + Ca and Chol-sNH4-Sil. A significant correlation between the tuber yield and SLA and LAR was not found, both in the cultivations with and without Si-based biostimulants. As mentioned, the tuber growth rate is slightly correlated with SLA [80], which was confirmed in the present study.

5. Conclusions

The current study showed that silicon application could provide a new perspective for improving plant growth and increasing early crop potato yields under water shortage conditions. Si-based biostimulants caused an increase in the early crop potato yield and contributed to improving the marketable yield value by increasing the productivity of medium-sized tubers (diameter of 40–50 mm). The Chol-sSA + Ca (Actisil) applications were the most effective. Na-Sil + Fe-EDTA (Optysil) produced better results during a warm and very dry year, while Chol-sNH4-Sil (Krzemix) was effective during colder years with a periodic water deficit. This study used mineral compounds other than silicon, making it difficult to conclude whether the observed effects were due to the silicon treatment itself or other minerals. Thus, future studies are necessary to quantify the amounts of other minerals in silicon sources and apply these values to other treatments to evaluate the plant-growth-promoting and yield-increasing effects of silicon itself and to develop recommendations for farmers.

Author Contributions

Conceptualization, W.W.; methodology, W.W.; formal analysis, W.W.; investigation, W.W.; writing—original draft preparation, W.W. and T.K.; writing—review and editing, W.W. and T.K.; visualization, T.K.; supervision, W.W. All authors have read and agreed to the published version of the manuscript.

Funding

This research received no external funding.

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

The original contributions presented in this study are included in the article. Further inquiries can be directed to the corresponding author.

Conflicts of Interest

The authors declare no conflicts of interest.

References

  1. Carrão, H.; Nauman, G.; Barbosa, P. Mapping global patterns of drought risk: An empirical framework based on sub-national estimates of hazard, exposure and vulnerability. Glob. Environ. Change 2016, 39, 108–124. [Google Scholar] [CrossRef]
  2. Farooq, M.; Wahid, A.; Kobayashi, N.; Fujita, D.; Basra, S.M.A. Plant drought stress: Effects, mechanisms and management. Agron. Sustain. Dev. 2009, 29, 185–212. [Google Scholar] [CrossRef]
  3. Wach, D.; Skowron, P. An overview of plant responses to the drought stress at morphological, physiological and biochemical levels. Pol. J. Agron. 2022, 50, 25–34. [Google Scholar]
  4. Bhupenchandra, I.; Devi, S.; Basumatary, A.; Dutta, S.; Singh, L.K.; Kalita, P.; Bora, S.S.; Devi, R.; Saikia, A.; Sharma, P.; et al. Biostimulants: Potential and prospects in agriculture. Int. Res. J. Pure Appl. Chem. 2020, 21, 20–35. [Google Scholar] [CrossRef]
  5. Shahrajabian, M.H.; Chaski, C.; Polyzos, N.; Petropoulos, S.A. Biostimulants application: A low input cropping management tool for sustainable farming of vegetables. Biomolecules 2021, 11, 698. [Google Scholar] [CrossRef]
  6. Zulfiqar, F.; Moosa, A.; Ali, H.A.; Bermejo, N.F.; Munné-Bosch, S. Biostimulants: A sufficiently effective tool for sustainable agriculture in the era of climate change? Plant Physiol. Biochem. 2024, 211, 108699. [Google Scholar] [CrossRef]
  7. Nunes da Silva, M.; Machado, J.; Osorio, J.; Duarte, R.; Santos, C.S. Non-essential elements and their role in sustainable agriculture. Agronomy 2022, 12, 888. [Google Scholar] [CrossRef]
  8. Mittal, U.; Kumar, V.; Kukreja, S.; Singh, B.; Pandey, N.K.; Goutam, U. Role of beneficial elements in developing resilience to abiotic and biotic stresses in plants: Present status and future prospects. J. Plant Growth Regul. 2023, 42, 3789–3813. [Google Scholar] [CrossRef]
  9. Singhal, R.K.; Fahad, S.; Kumar, E.; Choyal, P.; Javed, T.; Jinger, D.; Singh, P.; Saha, D.; MD, P.; Bose, B.; et al. Beneficial elements: New players in improving nutrient use efficiency and abiotic stress tolerance. Plant Growth Regul. 2023, 100, 237–265. [Google Scholar] [CrossRef]
  10. Zargar, S.M.; Mahajan, R.; Bhat, J.A.; Nazir, M.; Deshmukh, R. Role of silicon in plant stress tolerance: Opportunities to achieve a sustainable cropping system. 3 Biotech 2019, 9, 73. [Google Scholar] [CrossRef]
  11. Achire, M.L.; Mundada, P.S.; Nikam, T.D.; Bapat, V.A.; Penna, S. Multifaceted role of silicon in mitigating environmental stresses in plants. Plant Physiol. Biochem. 2021, 169, 291–310. [Google Scholar] [CrossRef] [PubMed]
  12. Kovács, S.; Kutasy, E.; Csajbók, J. The multiple role of silicon nutrition in alleviating environmental stresses in sustainable crop production. Plants 2022, 11, 1223. [Google Scholar] [CrossRef] [PubMed]
  13. Ahmed, S.R.; Anwar, Z.; Shahbaz, U.; Skalicky, M.; Ijaz, A.; Tariq, M.S.; Zulfiqar, U.; Brestic, M.; Alabdallah, N.M.; Alsubeie, M.S.; et al. Potential role of silicon in plants against biotic and abiotic stresses. Silicon 2023, 15, 3283–3303. [Google Scholar] [CrossRef]
  14. Khanum, S.; Tawaha, A.R.M.; Karimirad, R.; Al-Tawaha, A.R. Beneficial effect of supplementation silicon on the plant under abiotic and biotic stress. Silicon 2023, 15, 2481–2491. [Google Scholar] [CrossRef]
  15. Thakral, V.; Raturi, G.; Sudhakaran, S.; Mandlik, R.; Sharma, Y.; Shivaraj, S.M.; Tripathi, D.K.; Sonah, H.; Deshmukh, R. Silicon, a quasi-essential element: Availability in soil, fertilizer regime, optimum dosage, and uptake in plants. Plant Physiol. Biochem. 2024, 208, 108459. [Google Scholar] [CrossRef]
  16. Mir, R.A.; Bhat, B.A.; Yousuf, H.; Islam, S.T.; Raza, A.; Rizvi, M.A.; Charagh, S.; Albaqami, M.; Sofi, P.A.; Zargar, S.M. Multidimensional role of silicon to activate resilient plant growth and to mitigate abiotic stress. Front. Plant Sci. 2022, 13, 819658. [Google Scholar] [CrossRef]
  17. Savvas, D.; Ntatsi, G. Biostimulant activity of silicon in horticulture. Sci. Hort. 2015, 196, 66–81. [Google Scholar] [CrossRef]
  18. Laane, H.M. The effect of foliar sprays with different silicon compounds. Plants 2018, 7, 45. [Google Scholar] [CrossRef]
  19. Shivaraj, S.M.; Mandlik, R.; Bhat, J.A.; Raturi, G.; Elbaum, R.; Alexander, L.; Tripathi, D.K.; Deshmukh, R.; Sonah, H. Outstanding questions on the beneficial role of silicon in crop plants. Plant Cell. Physiol. 2022, 63, 4–18. [Google Scholar] [CrossRef]
  20. De Souza Júnior, J.P.; de Melo Prado, R.; Ferreira Diniz, J.; de Farias Guedes, V.H.; da Silva, J.L.F.; Roque, C.G.; de Cássia Felix Alvarez, R. Foliar application of innovative sources of silicon in soyabean, cotton, and maize. J. Soil Sci. Plant Nutr. 2022, 22, 3200–3211. [Google Scholar] [CrossRef]
  21. Malik, M.A.; Wani, A.H.; Mir, S.H.; Rehman, I.U. Elucidating role of silicon in drought stress tolerance in plants. Plant Physiol. Biochem. 2021, 165, 187–195. [Google Scholar] [CrossRef] [PubMed]
  22. Rehman, M.; Ilahi, H.; Adnan, M.; Wahid, F.; Rehman, F.; Ullah, A.; Ullah, A.; Zia, A.; Raza, M.A. Application of silicon: A useful way to mitigate drought stress: An overview. Curr. Rese. Agric. Far. 2021, 2, 9–15. [Google Scholar] [CrossRef]
  23. Wang, M.; Wang, R.; Mur, L.A.J.; Ruan, J.; Shen, Q.; Guo, S. Function of silicon in plant drought stress response. Hort. Res. 2021, 8, 254. [Google Scholar] [CrossRef] [PubMed]
  24. Verma, K.K.; Song, X.-P.; Lin, B.; Guo, D.-J.; Singh, M.; Rajput, V.D.; Singh, R.K.; Singh, P.; Sharma, A.; Malviya, M.K.; et al. Silicon induces drought tolerance in crop plants: Physiological adaptation strategies. Silicon 2022, 14, 2473–2487. [Google Scholar] [CrossRef]
  25. Irfan, M.; Maqsood, M.A.; Rehman, H.u.; Mahboob, W.; Sarwar, N.; Hafeez, O.B.A.; Hussain, S.; Ercisli, S.; Akhtar, M.; Aziz, T. Silicon nutrition in plants under water-deficit conditions: Overview and prospects. Water 2023, 15, 739. [Google Scholar] [CrossRef]
  26. Ahmad, M.; El-Saeid, M.H.; Akram, M.A.; Ahmad, H.R.; Haroon, H.; Hussain, A. Silicon fertilization—A tool to boost up drought tolerance in wheat (Triticum aestivum L.) crop for better yield. J. Plant Nutr. 2016, 39, 1283–1291. [Google Scholar] [CrossRef]
  27. Kowalska, J.; Tyburski, J.; Jakubowska, M.; Krzymińska, J. Effect of different form of silicon on growth of spring wheat cultivated in organic farming system. Silicon 2021, 13, 211–217. [Google Scholar] [CrossRef]
  28. Laane, H.M. The effects of the application of foliar sprays with stabilized silicic acids: An overview of the results from 2003-2004. Silicon 2017, 9, 803–807. [Google Scholar] [CrossRef]
  29. Neeru, J.; Shaliesh, C.; Vaishali, T.; Purav, S.; Manoherlal, R. Role of orthosilicic acid (OSA) based formulation in improving plant growth and development. Silicon 2019, 11, 2407–2411. [Google Scholar] [CrossRef]
  30. Alayafi, A.H.; Al-Solaimani, S.G.M.; Abd El-Wahed, M.H.; Alghabari, F.M.; Sabagh, A.E. Silicon supplementation enhances productivity, water use efficiency and salinity tolerance in maize. Front. Plant Sci. 2022, 13, 953451. [Google Scholar] [CrossRef]
  31. Dorneles, A.O.S.; Pereira, A.S.; Possebom, G.; Sasso, V.M.; Rossato, I.V.; Tabaldi, L.A. Growth of potato genotypes under different silicon concentrations. Adv. Hort. Sci. 2018, 32, 289–295. [Google Scholar]
  32. Crusciol, C.A.C.; Pulz, A.L.; Lemos, L.B.; Soratto, R.P.; Lima, G.P.P. Effect of silicon and drought stress on tuber yield and leaf biochemical characteristics in potato. Crop Sci. 2009, 49, 949–954. [Google Scholar] [CrossRef]
  33. Pilon, C.; Soratto, R.P.; Broetto, F.; Fernandes, A.M. Foliar or soil application of silicon alleviate water-deficit stress of potato plants. Agron. J. 2014, 106, 2325–2334. [Google Scholar] [CrossRef]
  34. Soltani, M.; Kafi, M.; Nezami, A.; Taghiyari, H.R. Effect of silicon application at nano and micro scales on the growth and nutrient uptake of potato minitubers (Solanum tuberosum var. Agria) in greenhouse conditions. BioNanoScience 2018, 8, 218–228. [Google Scholar] [CrossRef]
  35. Saadatian, B.; Kafi, M.; Bannayan, M.; Hammami, H. Effect of foliar spraying nano and ionized silicon on physiological characteristics and yield of potato (Solanum tuberosum L.) mini-tuber. Silicon 2022, 14, 8067–8079. [Google Scholar] [CrossRef]
  36. Soratto, R.P.; Fernandes, A.M.; Crusciol, C.A.C.; Souza-Schlick, G.D. Yield, tuber quality, and disease incidence on potato crops as affected by silicon leaf application. Pesq. Agropec. Bras. 2012, 47, 1000–1006. (In Portuguese) [Google Scholar] [CrossRef]
  37. Kafi, M.; Nabati, J.; Saadatian, B.; Oskoucian, A.; Shabahang, J. Potato response to silicon (micro- and nanoparticles) and potassium as affected by salinity stress. Ital. J. Agron. 2019, 14, 162–169. [Google Scholar] [CrossRef]
  38. Seleiman, M.F.; Al-Selwey, W.A.; Ibrahim, A.A.; Shady, M.; Alsadon, A.A. Foliar application of ZnO and SiO2 nanoparticles mitigate water deficit and enhance potato yield and quality traits. Agronomy 2023, 13, 466. [Google Scholar] [CrossRef]
  39. George, T.S.; Taylor, M.A.; Dodd, I.C.; White, P.J. Climate change and consequences for potato production: A review for tolerance to emerging abiotic stress. Potato Res. 2017, 60, 239–268. [Google Scholar] [CrossRef]
  40. Hijmans, R.J. The effect of climate change on global potato production. Am. J. Potato Res. 2003, 80, 271–279. [Google Scholar] [CrossRef]
  41. Raymundo, R.; Asseng, S.; Robertson, R.; Petsakos, A.; Hoogenboom, G.; Quiroz, R.; Hareau, G.; Wolf, J. Climate change impact on global potato production. Eur. J. Agron. 2018, 100, 87–98. [Google Scholar] [CrossRef]
  42. Chang, D.C.; Jin, Y.I.; Nam, J.H.; Cheon, C.G.; Cho, J.H.; Kim, S.J.; Yu, H.-S. Early drought effect on canopy development and tuber growth of potato cultivars with different maturities. Field Crops Res. 2015, 215, 156–162. [Google Scholar] [CrossRef]
  43. Wagg, C.; Hann, S.; Kupriyanovich, Y.; Li, S. Timing of short period water stress determines potato plant growth, yield and tuber quality. Agric. Water Manag. 2021, 247, 106731. [Google Scholar] [CrossRef]
  44. Li, S.; Kupriyanovich, Y.; Wagg, C.; Zheng, F.; Hann, A. Water deficit duration affects potato plant growth, yield and tuber quality. Agriculture 2023, 13, 2007. [Google Scholar] [CrossRef]
  45. Rykaczewska, K. The impact of high temperature during growing season on potato cultivars with different response to environmental stresses. Am. J. Plant Sci. 2013, 4, 2386–2393. [Google Scholar] [CrossRef]
  46. Kim, Y.-U.; Seo, B.-S.; Choi, D.-H.; Ban, H.-Y.; Lee, B.-W. Impact of high temperature on the marketable tuber yield and related traits of potato. Eur. J. Agron. 2017, 89, 46–52. [Google Scholar] [CrossRef]
  47. Zhang, G.; Tang, R.; Niu, S.; Si, H.; Yang, Q.; Bizimungu, B.; Regan, S.; Li, X.-Q. Effect of earliness on heat stress tolerance in fifty potato cultivars. Am. J. Potato Res. 2020, 97, 23–32. [Google Scholar] [CrossRef]
  48. Vulavala, V.K.R.; Elbaum, R.; Yermiyabu, U.; Fogelman, E.; Kuma, A.; Ginzberg, I. Silicon fertilization of potato: Expression of putative transporters and tuber skin quality. Planta 2016, 243, 217–229. [Google Scholar] [CrossRef]
  49. Puppe, D.; Busse, J.; Stein, M.; Kaczorek, D.; Buhtz, C.; Schaller, J. Silica accumulation in potato (Solanum tuberosum L.) plants and implications for potato yield performance—Results from field experiments in Northeast Germany. Biology 2024, 13, 828. [Google Scholar] [CrossRef]
  50. Luz, J.M.Q.; Rodrigues, C.R.; Gonçalves, M.V.; Coelho, L. The effect of silicon on potatoes in Minas Gerais, Brazil. In Proceedings of the 4th International Conference on Silicon in Agriculture, Durban, South Africa, 26–31 October 2008; p. 60. [Google Scholar]
  51. Nyawade, S.; Gitari, H.I.; Karanja, N.N.; Gachene, C.K.K.; Schulte-Geldermann, E.; Sharma, K.; Parker, M.L. Enhancing climate resilience of rain-red potato through legume intercropping and silicon application. Front. Sustain. Food Syst. 2020, 4, 566345. [Google Scholar] [CrossRef]
  52. Trawczyński, C. Assess of tuber yield and quality after foliar application of silicon and microelements. Agron. Sci. 2021, 76, 9–20. (In Polish) [Google Scholar] [CrossRef]
  53. Wadas, W. Possibility of increasing early potato yield with foliar application of silicon. Agron. Sci. 2022, 77, 61–75. [Google Scholar] [CrossRef]
  54. IUSS Working Group WRB. World Reference Base for Soil Resources. In International Soil Classification System for Naming Soils and Creating Legends for Soil Maps, 4th ed.; International Union of Soil Science (IUSS): Vienna, Austria, 2022. [Google Scholar]
  55. Nowacki, W. (Ed.) Characteristic of Native Potato Cultivars Register, 25th ed.; Plant Breeding Acclimatization Institute-National Research Institute: Jadwisin, Poland, 2022; p. 45. [Google Scholar]
  56. Meier, U. Growth Stages of Mono- and Dicotyledonous Plants: BBCH Monograph; Open Agrar Repositorium: Quedlinburg, Germany, 2018; pp. 1–204. [Google Scholar]
  57. Wadas, W.; Kalinowski, K. Effect of titanium on growth of very early-maturing potato cultivars. Acta Sci. Pol. Hortorum Cultus 2017, 16, 125–138. [Google Scholar] [CrossRef]
  58. Pietkiewicz, S. An indicator-based analysis of plant growth. Wiad. Bot. 1985, 29, 29–42. (In Polish) [Google Scholar]
  59. Wadas, W. Potato (Solanum tuberosum L.) growth in response to foliar silicon application. Agronomy 2021, 11, 2423. [Google Scholar] [CrossRef]
  60. De Oliveira, R.L.L.; de Mello Prado, R.; Felisberto, G.; Cruz, F.J.R. Different sources of silicon foliar spraying on the growth and gas exchange in sorghum. J. Soil Sci. Plant Nutr. 2019, 19, 948–953. [Google Scholar] [CrossRef]
  61. De Silva, V.F.; Moraes, J.C.; Melo, B.A. Influence of silicon on the development, productivity and infestation by insect pests in potato crops. Cienc. Agrotec. 2010, 34, 1465–1469. [Google Scholar] [CrossRef]
  62. Tavanti, T.R.; Melo, A.A.; Moreira, L.D.K.; Sanchez, D.E.J.; Silva, R.D.S.; Silva, R.M.D.; Reis, A.R.D. Micronutrient fertilization enhances ROS scavenging system for alleviation of abiotic stress in plants. Plant Physiol. Biochem. 2021, 160, 386–396. [Google Scholar] [CrossRef]
  63. Gupta, S.; Kaur, N.; Kant, K.; Jindal, P.; Ali, A.; Naeem, M. Calcium: A master regulator of stress tolerance in plants. S. Afr. J. Bot. 2023, 163, 580–594. [Google Scholar] [CrossRef]
  64. Hill, D.; Nelson, C.; Hammond, J.; Bell, L. Morphological of potato (Solanum tuberosum L.) in response to drought stress: Paving the way forward. Front. Plant Sci. 2021, 11, 597554. [Google Scholar] [CrossRef]
  65. Boguszewska-Mańkowska, D.; Pieczyński, M.; Wyrzykowska, A.; Kalaji, H.M.; Sieczko, L.; Szweykowska-Kulińska, Z.; Zagdańska, B. Divergent strategies displayed by potato (Solanum tuberosum L.) cultivars to cope with soil drought. J. Agro. Crop Sci. 2018, 204, 13–30. [Google Scholar] [CrossRef]
  66. Mushtaq, N.; Altaf, M.A.; Ning, J.; Shu, H.; Fu, H.; Lu, X.; Cheng, S.; Wang, Z. Silicon improves the drought tolerance in pepper plants through the induction of secondary metabolites, GA biosynthesis pathway, and suppression of chlorophyll degradation. Plant Physiol. Biochem. 2024, 214, 108919. [Google Scholar] [CrossRef] [PubMed]
  67. Zrůst, J.; Hlušek, J.; Jůzl, M.; Přichystalová, V. Relationship between certain chosen growth characteristics of very early potato varieties. Rostl. Výr. 1999, 45, 503–509. (In Czech) [Google Scholar]
  68. Udding, J.; Gelang-Alfredsson, G.; Piikki, K.; Pleijel, H. Evaluating the relationship between leaf chlorophyll content and SPAD-502 chlorophyll meter readings. Photosynth. Res. 2007, 91, 37–46. [Google Scholar] [CrossRef]
  69. Wadas, W.; Dębski, H. Effect of silicon foliar application on the assimilation area and photosynthetic pigment contents of potato (Solanum tuberosum L.). Appl. Ecol. Environ. Res. 2022, 20, 1369–1384. [Google Scholar] [CrossRef]
  70. Cao, B.; Ma, Q.; Zhao, Q.; Wang, L.; Xu, K. Effect of silicon on absorbed light allocation, antioxidant enzymes and ultrastructure of chloroplasts in tomato leaves under simulated drought stress. Sci. Hort. 2015, 194, 53–62. [Google Scholar] [CrossRef]
  71. Zhang, R.; Zhang, W.; Kang, Y.; Shi, M.; Yang, X.; Li, H.; Yu, H.; Wang, Y.; Qin, S. Application of different iron fertilizers for improving the photosynthesis and tuber quality of potato (Solanum tuberosum L.) and enhancing iron biofortification. Chem. Biol. Technol. Agric. 2022, 9, 79. [Google Scholar] [CrossRef]
  72. Pilon, C.; Soratto, R.; Moreno, L.A. Effects of soil and foliar application of soluble silicon on mineral nutrition, gas exchange, and growth of potato plants. Crop Sci. 2013, 53, 1605–1614. [Google Scholar] [CrossRef]
  73. Ramírez, D.A.; Yactayo, W.; Gutiérrez, R.; Mares, V.; De Mendiburu, F.; Posadas, A.; Quiroz, R. Chlorophyll concentration in leaves is an indicator of potato tuber yield in water-shortage conditions. Sci. Hort. 2014, 168, 202–209. [Google Scholar] [CrossRef]
  74. Rolando, J.L.; Ramirez, D.A.; Yactayo, W.; Monneveux, P.; Quiroz, R. Leaf greenness as a drought tolerance related trait in potato (Solanum tuberosum L.). Environ. Exp. Bot. 2015, 110, 27–35. [Google Scholar] [CrossRef]
  75. Van Delden, A.; Pecio, A.; Haverkot, A.J. Temperature response of early foliar expansion of potato and wheat. Ann. Bot. 2000, 86, 355–369. [Google Scholar] [CrossRef]
  76. Howlader, O.; Hoque, M.A. Growth analysis and yield performance of four potato (Solanum tuberosum L.) varieties. Bangladesh J. Agric. Res. 2018, 43, 267–280. [Google Scholar] [CrossRef]
  77. Camargo, D.C.; Montoya, F.; Moreno, M.A.; Ortega, J.F.; Córcoles, J.I. Impact of water deficit on light interception, radiation use efficiency and leaf area index in a potato crop (Solanum tuberosum L.). J. Agric. Sci. 2016, 154, 662–673. [Google Scholar] [CrossRef]
  78. Schittenhelm, S.; Sourell, H.; Lopmeier, F.-J. Drought resistance of potato cultivars with contrasting canopy architecture. Eur. J. Agron. 2006, 24, 193–202. [Google Scholar] [CrossRef]
  79. Rizvi, S.; Mushtaq, F.; Hussain, K.; Farwah, S.; Afroza, B.; Hussain, S.M.; Saleem, S. Correlation analysis for various growth and yield attributing traits in potato (Solanum tuberosum L.) genotypes. Int. J. Chem. Stud. 2020, 8, 1738–1740. [Google Scholar] [CrossRef]
  80. Ascione, S.; Ruggiero, C.; Vitale, C. Contribution of growth components on relative, plant crop and tuber growth rate of nine potato cultivars in southern Italy. Int. J. Sci. 2013, 2, 1–11. [Google Scholar]
Agriculture 15 00556 g001
Figure 1. Mean air temperature (lines) and total precipitation (bars) during potato growth.
Figure 1. Mean air temperature (lines) and total precipitation (bars) during potato growth.
Agriculture 15 00556 g001
Agriculture 15 00556 g002
Figure 2. Plant height and above-ground biomass in relation to treatment and year (a) and treatment and cultivar (b). Mean and standard deviation. Means for each data type, indicated with the same letters, do not differ significantly according to Tukey’s post hoc test (p ≤ 0.05).
Figure 2. Plant height and above-ground biomass in relation to treatment and year (a) and treatment and cultivar (b). Mean and standard deviation. Means for each data type, indicated with the same letters, do not differ significantly according to Tukey’s post hoc test (p ≤ 0.05).
Agriculture 15 00556 g002
Agriculture 15 00556 g003
Figure 3. Leaf area and chlorophyll (ChlSPAD) content in relation to treatment and year (a) and treatment and cultivar (b). Mean and standard deviation. Means for each data type, indicated with the same letters, do not differ significantly according to Tukey’s post hoc test (p ≤ 0.05).
Figure 3. Leaf area and chlorophyll (ChlSPAD) content in relation to treatment and year (a) and treatment and cultivar (b). Mean and standard deviation. Means for each data type, indicated with the same letters, do not differ significantly according to Tukey’s post hoc test (p ≤ 0.05).
Agriculture 15 00556 g003
Agriculture 15 00556 g004
Figure 4. Plant growth indicators in relation to treatment and year (a) and treatment and cultivar (b). LAI—leaf area index, SLA—specific leaf area, LAR—leaf area ratio, LWR—leaf weight ratio. Mean and standard deviation. Means for each data type, indicated with the same letters, do not differ significantly according to Tukey’s post hoc test (p ≤ 0.05).
Figure 4. Plant growth indicators in relation to treatment and year (a) and treatment and cultivar (b). LAI—leaf area index, SLA—specific leaf area, LAR—leaf area ratio, LWR—leaf weight ratio. Mean and standard deviation. Means for each data type, indicated with the same letters, do not differ significantly according to Tukey’s post hoc test (p ≤ 0.05).
Agriculture 15 00556 g004
Agriculture 15 00556 g005
Figure 5. Tuber number and tuber weight per plant in relation to treatment and year (a) and treatment and cultivar (b). Mean and standard deviation. Means for each data type, indicated with the same letters, do not differ significantly according to Tukey’s post hoc test (p ≤ 0.05).
Figure 5. Tuber number and tuber weight per plant in relation to treatment and year (a) and treatment and cultivar (b). Mean and standard deviation. Means for each data type, indicated with the same letters, do not differ significantly according to Tukey’s post hoc test (p ≤ 0.05).
Agriculture 15 00556 g005
Agriculture 15 00556 g006
Figure 6. Tuber yield in relation to treatment and year (a) and treatment and cultivar (b). Mean and standard deviation. Means for each data type, indicated with the same letters, do not differ significantly according to Tukey’s post hoc test (p ≤ 0.05).
Figure 6. Tuber yield in relation to treatment and year (a) and treatment and cultivar (b). Mean and standard deviation. Means for each data type, indicated with the same letters, do not differ significantly according to Tukey’s post hoc test (p ≤ 0.05).
Agriculture 15 00556 g006
Agriculture 15 00556 g007
Figure 7. Tuber size in yield in relation to treatment and year (a) and treatment and cultivar (b). Percentage weight of tubers with diameter of <30 mm, 31–40 mm, 41–50 mm, and >50 mm.
Figure 7. Tuber size in yield in relation to treatment and year (a) and treatment and cultivar (b). Percentage weight of tubers with diameter of <30 mm, 31–40 mm, 41–50 mm, and >50 mm.
Agriculture 15 00556 g007
Table 1. Linear correlation coefficients between tuber yield and potato-plant growth traits under varied hydrothermal conditions (n = 12).
Table 1. Linear correlation coefficients between tuber yield and potato-plant growth traits under varied hydrothermal conditions (n = 12).
Plant Growth TraitsTotal YieldMarketable Yield
202020212022202020212022
Plant height−0.7227 **−0.4406−0.8146 **−0.7306 **−0.5745−0.7684 **
Stem weight−0.6776 *−0.3152−0.7013 *−0.6825 *−0.4059−0.6688 *
Leaf weight0.5947 *0.56240.47200.6037 *0.46020.5705
Leaf area0.50270.25020.43620.50590.52920.5237
ChlSPAD−0.5860 *0.26560.2409−0.6164 *−0.22360.2346
Leaf area index (LAI)0.50390.25100.43140.50690.53620.5192
Specific leaf area (SLA)0.0502−0.6336 *−0.38430.0661−0.6028 *−0.3692
Leaf area ratio (LAR)0.7905 **0.6094 *0.8356 **0.7961 **0.6992 *0.8393 **
Leaf weight ratio (LWR)0.8060 **0.6435 *0.8186 **0.8224 **0.7696 **0.8466 **
Tuber number per plant0.9660 **0.8651 **0.8403 **0.9654 **0.7793 **0.7681 **
Tuber weight per plant0.9721 **0.5783 *0.9936 **0.9782 **0.6719 *0.9630 **
* significant at p ≤ 0.05; ** significant at p ≤ 0.01.
Table 2. Linear correlation coefficients between tuber yield and potato-plant growth traits, following the application of Si-based biostimulants (n = 9).
Table 2. Linear correlation coefficients between tuber yield and potato-plant growth traits, following the application of Si-based biostimulants (n = 9).
Plant Growth TraitsTotal YieldMarketable Yield
ControlActisilKrzemixOptysilControlActisilKrzemixOptysil
Plant height−0.2202−0.4748−0.3713−0.3678−0.1974−0.4829−0.3443−0.2886
Stem weight0.1600−0.3284−0.1803−0.11900.1675−0.3556−0.15880.3364
Leaf weight0.8394 **0.8378 **0.8521 **0.8740 **0.8394 **0.8251 **0.8666 **0.8576 **
Leaf area0.8098 **0.7476 *0.7878 *0.7223 *0.8156 **0.7238 *0.7842 *0.7295 *
ChlSPAD0.9296 **0.8738 **0.7302 *0.6842 *0.9419 **0.8888 **0.7367 *0.6839 *
Leaf area index (LAI)0.8109 **0.7488 *0.7846 *0.7229 *0.8170 **0.7252 *0.7806 *0.7300 *
Specific leaf area (SLA)−0.4051−0.5637−0.1508−0.5467−0.3870−0.5854−0.1872−0.4729
Leaf area ratio (LAR)0.34560.47120.66290.39480.33770.48260.64070.3865
Leaf weight ratio (LWR)0.47630.6853 *0.6719 *0.60700.46310.7018 *0.6838 *0.5617
Tuber number per plant0.7328 *0.7593 *0.8310 **0.8215 **0.7544 *0.7153 *0.7806 *0.7727 *
Tuber weight per plant0.9954 **0.9934 **0.9820 **0.9945 **0.9967 **0.9941 **0.9894 **0.9940 **
* significant at p ≤ 0.05; ** significant at p ≤ 0.01.
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

Share and Cite

MDPI and ACS Style

Wadas, W.; Kondraciuk, T. The Role of Foliar-Applied Silicon in Improving the Growth and Productivity of Early Potatoes. Agriculture 2025, 15, 556. https://doi.org/10.3390/agriculture15050556

AMA Style

Wadas W, Kondraciuk T. The Role of Foliar-Applied Silicon in Improving the Growth and Productivity of Early Potatoes. Agriculture. 2025; 15(5):556. https://doi.org/10.3390/agriculture15050556

Chicago/Turabian Style

Wadas, Wanda, and Tomasz Kondraciuk. 2025. "The Role of Foliar-Applied Silicon in Improving the Growth and Productivity of Early Potatoes" Agriculture 15, no. 5: 556. https://doi.org/10.3390/agriculture15050556

APA Style

Wadas, W., & Kondraciuk, T. (2025). The Role of Foliar-Applied Silicon in Improving the Growth and Productivity of Early Potatoes. Agriculture, 15(5), 556. https://doi.org/10.3390/agriculture15050556

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop