4.1. The Influence of Ultrasound Technology on Plant Growth and Seed Potato Yield
The discussion regarding the application of ultrasonics in potato cultivation is a fascinating subject, as this technology appears to have the potential to influence various aspects of plant growth and yield, including stem count per plant, seed tuber yield, and other tuber characteristics. Analysis of the results presented in
Table 5 indicates that the use of ultrasonics prior to planting significantly increased the number of stems per plant compared to the control technology. Similar results were obtained by [
6]. The first significant conclusion is that the application of ultrasonics seems to have a positive impact on plant growth. Although these differences were not statistically confirmed for most varieties, the trend towards a higher stem count suggests a beneficial effect of this technology.
The number of stems per plant varied depending on the potato variety. Varieties such as 'Satina' and 'Denar' exhibited the highest number of stems per plant, suggesting their higher responsiveness to ultrasonic stimulation. On the other hand, the variety 'Zagłoba', although showing a lower number of stems compared to some other varieties, could still benefit from the effects of ultrasonics, as this trend was evident in the research sample. It is also important to note that the impact of the number of stems per plant can have significant consequences for potato yield. A greater number of stems can lead to higher production of seed potato tubers and increased tuber mass, influencing both the quantity of tubers for planting and overall yield.
To better explain this relationship using the latest knowledge, we can delve into recent research on plant physiology and ultrasonic technology. Recent studies have shown that ultrasonic stimulation can enhance various physiological processes in plants, including cell division, nutrient uptake, and hormone synthesis [
1,
5]. These effects can contribute to increased branching and stem formation in plants, thereby leading to a higher number of stems per plant. Additionally, ultrasonic waves can stimulate root development, leading to better nutrient absorption and overall plant growth. Understanding these mechanisms can provide insights into how ultrasonics influence the number of stems per plant and, consequently, potato yield. Furthermore, advancements in molecular biology and genetics have shed light on the genetic basis of plant responses to ultrasonic stimulation, offering valuable insights into the specific mechanisms underlying the variability in stem number among different potato varieties. By integrating this multidisciplinary approach, we can gain a comprehensive understanding of the relationship between ultrasonics, stem number, and potato yield, leveraging the latest knowledge to optimize agricultural practices and enhance crop productivity.
The impact of ultrasonics on the overall tuber yield is an important aspect that can be analyzed based on the data presented in
Figure 2(a). This is important as it allows understanding how modern technologies, such as ultrasonics, can affect crop yield compared to traditional methods. From the analysis of this figure, several important conclusions can be drawn. Firstly,
Figure 2(a) shows whether the use of ultrasonics before bulb planting affects the increase in the overall potato tuber yield. The results obtained indicate that ultrasonic cultivation technology yields a higher yield compared to traditional technology, and on this basis, it can be inferred that ultrasonics have a positive impact on tuber formation and production. Secondly, it is worth comparing the differences in tuber yield between different cultivation technologies to determine if these differences are statistically significant. If ultrasonic cultivation shows a significantly higher yield than traditional cultivation, it can be considered an effective method of improving yield. Additionally, other factors such as weather conditions and differences between potato varieties should also be taken into account. These factors can affect the overall tuber yield and should be considered in the context of analyzing the impact of ultrasonics. Based on
Figure 2(d), interactions between cultivation technologies and different potato varieties and their impact on overall tuber yield can also be analyzed. This allows for a better understanding of which combinations of technologies and varieties are most effective in tuber production.
In summary, the discussion on the impact of ultrasonics on the overall potato tuber yield should consider both the data presented in
Figure 2(a) and additional factors such as weather conditions and varietal differences to accurately assess the effectiveness of this technology in potato cultivation. Similar studies on this topic were conducted by [
6]. These authors obtained comparable results from the use of ultrasonic cultivation technology before bulb planting.
The average yield of potato seedlings was nearly 38 t/ha, indicating generally high productivity. The use of ultrasonic technology before planting significantly increased the yield of potato seedlings per unit area by approximately 7% compared to the control combination. There is a lack of data on this topic in the available literature; however, it can be assumed that this effect may be attributed to ultrasonic technology, which could influence improved water and nutrient uptake by plant roots, thus contributing to better plant growth and productivity. To determine whether the increased yield of potato seedlings is caused by higher cavitation, scientific research and experiments would be necessary to understand the exact mechanism of ultrasonic technology on potato plants and their impact on potato seedling yield. Cavitation is a physical phenomenon involving the formation and collapse of gas bubbles in a liquid due to pressure changes. In agriculture, especially in the context of technologies used in plant cultivation, cavitation can be utilized in various processes such as irrigation, fertilizer mixing, or in microbiology for pathogen destruction in water [
19,
25,
26,
27].
The number of seedlings per unit area. The use of ultrasonic technology before planting significantly increased the number of seedlings compared to traditional technology without this treatment. This means that the use of ultrasonics before planting can increase the number of seedlings by almost 9%, which corresponds to approximately 27 thousand seedlings per hectare. Such a difference could allow for the additional planting of nearly 1 hectare of cultivation area.
The interaction between varieties and cultivation technologies is also significant. In most cases, the use of ultrasonics led to an increase in the number of seedlings per hectare, suggesting a positive impact of this technology on seedling production. Some varieties, such as 'Satina,' 'Tajfun,' and 'Denar,' showed the greatest response to the ultrasonic treatment before planting, while other varieties reacted to a lesser extent. The conclusion drawn from these observations is that the choice of cultivation technology, including the use of ultrasonics before planting, can have a significant impact on the number of seedlings per hectare. This is important in terms of optimizing the use of available cultivation area and achieving the desired yield.
Discussing the weight of individual potato seedlings in the context of the data from
Table 9 requires considering various factors influencing this trait and their significance for yield and cultivation efficiency. The first significant conclusion is that the weight of individual potato seedlings has a significant impact on yield and the seed multiplication rate. A higher average weight of individual potato seedlings usually leads to a greater number of tubers produced from one seedling. This means that plants have the potential to produce a greater quantity of tubers, which in turn can contribute to an increase in the overall potato yield per hectare. Analysis of the data from
Table 9 shows significant differences in the weight of individual potato seedlings depending on the factors studied, such as cultivation technology, potato varieties, and cultivation years. The use of ultrasonic technology before planting did not have a significant impact on this trait, but some varieties, such as 'Lord' and 'Vineta,' showed a tendency to increase the weight of individual seedlings under the influence of this technology.
The interaction of cultivation technologies with the years of study also had a significant impact on the weight of individual potato seedlings. A clear beneficial effect of this technology was observed in 2017, allowing for the protection of potatoes during vegetative growth in unusual weather conditions, as well as the production of larger individual tubers to withstand drought and ensure potato reproduction in the following cycle. In summary, the weight of individual potato seedlings is a significant factor affecting yield and cultivation efficiency, and its analysis and discussion should take into account various environmental, technological, and genetic factors of potato varieties.
The multiplication coefficient of potatoes in the context of the data from
Table 10 requires considering its significance for assessing the efficiency of potato seedling production and various factors influencing this trait. The potato multiplication coefficient is an important indicator of bulb production efficiency because it reflects the number of bulbs that can be obtained from one seed bulb. Analysis of the data from
Table 10 shows that the average value of this coefficient in the study was 7.8. The use of sonication of bulbs before planting contributed to a significant increase in this coefficient compared to traditional technology, from 7.5 to 8.2. The response of the studied varieties to cultivation technologies using ultrasonics before planting was varied. The 'Satina' variety showed the greatest response to this technology, while the 'Vineta' variety showed no response to the applied sonication of bulbs before planting. In summary, the discussion on the potato multiplication coefficient should consider both its significance for the efficiency of potato bulb production and the impact of various factors such as cultivation technologies, potato varieties, and environmental and climatic conditions on this trait.
Potential benefits associated with the use of ultrasonics in potato cultivation may include increased potato yield, better plant resistance to environmental stresses, reduced pesticide usage, and improved crop quality. In terms of crop quality improvement, Mierzwa et al. [
28] have reported on the benefits of ultrasonically assisted vacuum impregnation for drying potato cubes, originally considered as valueless production waste. According to these authors, this approach allows for the transformation of valueless production waste into a valuable product with a high content of impregnating compounds (in this case, ascorbic acid). Furthermore, the changes induced by ultrasonics contributed to improving the energy efficiency of further processing steps, providing added value. Additionally, the authors note that ultrasonics had a positive impact on the kinetics and energy consumption of convective drying. The obtained results suggest that the use of ultrasonics may be a promising technology supporting the growth and yield of potato plants, but further research is needed to better understand the mechanisms of ultrasonic influence on plants and optimize their application in agricultural practice.
In conclusion, the discussion on the use of ultrasonics in potato cultivation technologies should consider both the benefits and concerns associated with this technology and requires rigorous scientific analysis, stakeholder dialogue, and monitoring of its effects.
4.2. Variability of Varieties and Their Drought Tolerance
The genetic properties of the tested varieties significantly influenced the overall yield, seed potato yield, number of seed potato, average mass of one seed potato, and multiplication coefficient of potatoes. Some varieties, such as 'Satina' and 'Denar', showed a tendency for higher seed potato production from calibrated tubers compared to other varieties. Genetic differences among the tested varieties significantly modified the yield. The most productive variety was 'Syrena', but within the same homogeneous group, other varieties such as 'Denar', 'Satina', and 'Zagłoba' also stood out. In the second homogeneous group, varieties like 'Lord' and 'Tajfun' were found, while in the least productive group were varieties like 'Vineta' and 'Owacja'. The variety 'Satina' exhibited the highest multiplication coefficient, while the remaining varieties could be divided into two homogeneous groups, suggesting differences in their reproductive abilities. Similar relationships related to the genetic characteristics of varieties were demonstrated by Sawicka [
11], Boguszewska-Mańkowska et al. [
29,
30,
31] and Zarzyńska et al. [
33].
Benefits and limitations of cultivating the tested potato varieties may result from various factors, such as genetic characteristics of the varieties, their adaptation to environmental conditions, yield potential, crop quality, and cultivation requirements [
29,
30,
31]. Particularly important is the response of potato varieties to drought stress, which is a complex process resulting from the interaction between plant genetics and environmental conditions. According to Grudzińska et al. [
32], drought negatively affects plants by limiting access to water, leading to various physiological, biochemical, and morphological changes in the plant, such as: restricted water availability, which inhibits physiological processes in plants such as photosynthesis, transpiration, water conduction, and mineral nutrient uptake, resulting in reduced plant growth and development; disturbances in water-electrolyte balance in plant cells, which can lead to increased oxidative stress; alterations in water and mineral nutrient transport, leading to reduced plant ability to uptake water and mineral nutrients from the soil. This, in turn, can lead to disruptions in the transport of these substances within the plant, resulting in nutrient deficiencies and disturbances in plant functioning [
29,
33]. As a result, the response of potato varieties to drought stress can lead to reduced yields, deterioration in tuber quality, and increased susceptibility to disease infections. However, plants may exhibit varying degrees of drought tolerance, depending mainly on their genetic resistance and degree of adaptation to environmental conditions. Therefore, breeding and selecting potato varieties with greater drought resistance are crucial for ensuring stable production in changing climate conditions.
The overall benefits and limitations associated with cultivating specific varieties are as follows: high yield potential; some varieties may exhibit higher yields compared to others, resulting in increased harvests per unit area; resistance to diseases and pests; good crop quality; cultivation flexibility [
29,
30,
31]. Limitations of the studied varieties include, among others: low environmental resistance, such as low resistance to drought, excessive humidity, or extreme air temperatures, which can lead to reduced tuber yields; susceptibility to diseases or pests, increasing the risk of infection-related losses; some varieties may require specific soil, climatic, or fertilization conditions, which can increase production costs or limit their application to certain regions; low stress tolerance and less flexibility in adapting to changing environmental conditions may result in decreased yield performance in case of stress occurrence [
31,
32,
33].
The benefits and limitations of cultivating individual potato varieties are diverse and depend on various factors. Therefore, selecting the appropriate variety for cultivation should take into account local environmental conditions, production goals, and the availability of agricultural technologies and plant protection. It is also important to consider the preferences of producers to understand their preferences regarding selected varieties in combination with ultrasound technology [
28].
The future prospects for the studied potato varieties depend on various factors, including climate change resilience, sustainable production, breeding innovations, enhanced disease resistance, and consumer preferences. Developing varieties resilient to changing weather conditions is crucial, along with sustainable production practices and innovations in breeding techniques. Increasing disease and pest resistance can mitigate losses, while meeting consumer preferences for taste, texture, and nutrition can boost market demand. Overall, continuous adaptation to new challenges and innovations in potato cultivation are essential for future success. Scientists are encouraged to continue researching the impact of different potato varieties combined with ultrasound technology and to monitor progress in their agricultural application.
4.3. Impact of Environmental Conditions on Potato Yield and Its Parameters
This problem is significant for the overall efficiency of potato cultivation. Factors such as soil moisture, temperature, sunlight availability, and nutrient availability can significantly influence plant growth and tuber formation. Optimal environmental conditions conducive to plant growth can lead to increased yield, a greater number of tubers, their mass, and quality. On the other hand, adverse conditions such as drought, excessive moisture, or nutrient deficiency can limit plant growth and result in reduced yield and tuber quality. Therefore, monitoring environmental conditions and proper management of them are crucial for achieving optimal potato yield and quality. The discussion on the impact of environmental conditions on potato yield and its parameters can be crucial for understanding the factors influencing cultivation efficiency. Various environmental factors, such as weather conditions (e.g., rainfall, temperature, sunlight, wind) and soil factors (e.g.: soil structure, pH, nutrient content, moisture), can significantly affect potato yield.
The average yield of potato tubers in the conducted experiment was high, but the variability in weather conditions during the study years had a significant impact on this yield. Yields in 2015 were significantly lower than in other years, suggesting unfavorable weather and soil conditions for potato yield. The highest yield was obtained in 2016, when weather conditions were optimal for potatoes. The yield of potato tubers in 2017 was higher than in 2015 but lower than in 2016, with optimal water supply during potato growth. Similar observations were made by Barbaś and Sawicka [
38] regarding the impact of meteorological conditions on tuber yield structure. They demonstrated that weather conditions during the potato growing season had the most significant influence on tuber yield. In years characterized by optimal rainfall and uniform moisture distribution during the growing season, the highest yields were observed for both commercial and seed potatoes. Conversely, years with dry vegetative periods were less favorable for achieving high yields in these aspects.
The potato varieties under study also showed a varied response to soil and climatic conditions during the research period. It was precisely the unusual weather patterns that led to significantly different yields among the tested varieties. In the group of varieties with the highest yields of potato tubers, 'Denar', 'Lord', 'Satina', and 'Syrena' were included. In the next group, with homogeneous yields, the varieties 'Vineta', 'Tajfun', and 'Zagłoba' were found, while the variety with the lowest yield of potato tubers was 'Owacja'.
Changes in the number of tubers per hectare were also observed in subsequent years of the study. The highest number of tubers was obtained in 2017, characterized by variable thermal-humidity conditions, while the lowest was in the dry year of 2015. These results suggest that atmospheric conditions and other environmental factors can have a significant impact on tuber production. Grudzińska et al. [
32] also noted a similar response to weather conditions. Boguszewska-Mańkowska et al. [
31] demonstrated that drought activates defense mechanisms, such as the accumulation of osmotic substances, antioxidant production, closure of stomata, and leaf structure changes to reduce transpiration. Physiological drought can lead to changes in plant metabolism, such as the accumulation of osmotically active compounds (e.g., proline, sugars), reduced photosynthesis activity, and changes in the activity of enzymes involved in carbohydrate, amino acid, and lipid metabolism.
Climatic and environmental conditions also significantly influenced the weight of individual average tubers. The highest value of this parameter was obtained in 2017, characterized by unusual weather conditions that could have influenced the intensity of tuber growth. Conversely, the lowest multiplication coefficient was obtained in 2015 during the drought period.
The diverse response of different potato varieties to weather conditions may result from genetic differences among these varieties and their adaptive capabilities to changing environmental conditions [
31,
32,
35,
41]. There are several factors that may influence this diverse reaction, including: a) different genetic traits affecting their resistance to weather conditions, such as drought, excessive moisture, high or low temperatures, or the presence of diseases or pests. Some varieties may be more resistant to specific weather conditions than others; b) adaptation to local conditions: some varieties may be better adapted to specific climatic and soil conditions prevailing in a particular region. Varieties well suited to certain conditions may show better tuber yields compared to varieties less adapted to these conditions; c) genetic flexibility: some varieties may be more genetically flexible, meaning they can better respond to variable weather conditions by quickly adapting to changes in the environment; d) genotype-environment interactions: the variety's response to weather conditions may also result from interactions between genetic traits and environmental conditions, meaning that the influence of weather conditions on plants can be modified by their genotype [
34,
36,
37,
38].
As a result, different potato varieties may exhibit varied reactions to weather conditions due to differences in their genetics, environmental adaptation, and genetic flexibility. Therefore, it is important to use different varieties depending on local growing conditions to maximize yield and crop resilience to variable weather conditions.
4.4. Correlations between Potato Tuber Characteristics
The Pearson correlation coefficient analysis indicates that the closer the coefficient value is to 1 or -1, the stronger the linear relationship between two variables. The number of stems has a moderately positive correlation with the total tuber yield, seed potato yield, the number of seed potatoes per unit area, and the average mass of a single the seed potato tuber. According to Priegnitz et al. [
39], increasing the number of stems from one potato plant can lead to higher seed potato yield because each stem has the potential to generate a greater number of tubers. Similar relationships are confirmed by the studies of Zarzyńska et al. [
37] and Barbaś and Sawicka [
38].
According to Sadawarti et al. [
40], an increase in the number of stems could potentially affect coefficient of multiplication, as a higher number of stems may indicate a greater total mass of harvested tubers, which could lead to a decrease in the multiplication coefficient if the mass of the harvested potato yield does not increase proportionally to the mass of seed potatoes.
The seed potato yield (x2) showed a high positive correlation both with their number (x4) and with the average mass of a single seed potatoes (x5). Meanwhile, the potato multiplication coefficient (x6) also exhibited a strong positive correlation with both the seed potato yield (x2), their number (x4), and the average mass of a single tuber (x5). The correlation coefficient value between the percentage of seed potatoes (x4) and the average mass of a single seed potato (x5) was r = -0.42. This indicates a moderately negative correlation between the percentage of seed potatoes and the average mass of a single tuber. However, it is worth noting that this relationship is not very strong. The correlation coefficient value between the number of seed potato tubers (x4) and the average mass of a single seed potatoes (x4) turned out to be exceptionally weak. These findings are confirmed by research conducted by Barbaś and Sawicka [
38] and Muhie et al. [
41].
Recent studies by Gu et al. [
42] have shown a significant positive correlation between the number of stems per potato plant and the total yield of tubers. They suggest that increasing stem density through optimal planting densities could enhance tuber yield without compromising tuber quality.
Additionally, research by Islam and Li [
43] found that the percentage of seed potato tubers in a crop has a strong negative correlation with tuber size distribution. This highlights the importance of seed potato quality and planting practices in achieving desired tuber characteristics.
Furthermore, Standardization of Seed Potato (GE.6) [
44] revealed that the average mass of one seed potato tuber is positively correlated with tuber yield but negatively correlated with tuber dry matter content. This suggests a trade-off between yield and quality that breeders and growers should consider in cultivar selection and the management practices.
These recent findings underscore the complexity of the relationships between various factors influencing potato productivity and call for interdisciplinary approaches to address the challenges and opportunities in potato cultivation.
Silva Filho et al. [
45] identified the following as the best parameters characterizing potato seedlings: main stem diameter, leaf count, length of the fourth leaf on the stem, leaf surface area, number of tubers per plant, root dry weight, and total dry weight. Days after transplanting (DAT) significantly influenced morphophysiological parameters, with 45 DAT being the optimal time for estimating seed potato yield, and data collected biweekly being as reliable as weekly harvests.
Therefore, further research is needed to investigate the impact of stem number, potato yield, proportion of seed potato tubers, and average mass of individual seed potato on the overall productivity of potatoes. These studies could lead to a better understanding of the relationships between these traits and the development of more effective breeding and agronomic strategies to enhance the yield and quality of potato cultivation. However, it is worth noting that there are other potential explanations for these relationships that should be explored in future research.