Certified Seed Use Enhances Yield Stability in Cereal Production Under Temperate Climate Conditions

Abstract

In the face of growing demand for food and climate change, ensuring the stability and height of crop yields is becoming a key challenge for modern agriculture. One of the solutions supporting the sustainable development of crop production is the use of certified seed. The aim of this study was to assess the impact of using certified seed on the level and stability of yields of three cereal species: winter wheat, winter triticale and spring barley, in temperate climate conditions. Data came from surveys conducted on over 8000 farms in six agroecoregions of Poland in 2021–2023. The analysis showed significantly higher yields on farms using certified seed for all species studied. Additionally, greater yield stability (lower values of Shukla variance and Wricke ecovalence) was noted in the case of using certified seeds, especially in region IV. This indicates the positive impact of certified seeds (e.g., genetic purity, health, and vigor) on the efficiency and resilience of agricultural systems. This phenomenon is of particular importance in the context of climate change and may be an important element of risk management strategies in agriculture.

1. Introduction

The growing demand for food, resulting from the growth of the global human population, leads to a significant increase in the demand for agricultural products. It is therefore necessary to intensify agricultural production while taking into account the growing environmental constraints [1,2]. One of the main challenges of modern agriculture is adaptation to changing climatic conditions, which pose an increasing threat to the stability and productivity of crops.

Achieving high and durable yields requires the use of modern agrotechnical methods. However, these methods have their limitations and regulatory pressure—including limiting mineral fertilization and the use of plant protection products—forces producers to seek alternative solutions. One of them is the use of high-quality seed, which is an example of so-called biological progress. Research by McGuire and Sperling [3,4] and a study by Deconinck et al. [5] indicate that sustainable seed systems play a key role in ensuring global food security.

The production of certified seed material takes place under strictly controlled conditions, maintaining rigorous quality standards [6]. Seed orchards require high-quality agricultural technology, chemical protection [7], and are evaluated both in the field and laboratory phases. This makes it possible to ensure healthy, uniform seeds that allow the potential of modern varieties to be used.

Certified seed not only ensures varietal purity and uniformity but also guarantees high physiological quality, including germination capacity and seed vigor. This aspect is particularly critical under climate change conditions, where crops are increasingly exposed to abiotic and biotic stresses such as drought, heat waves, and pathogen outbreaks. High seed vigor translates into faster and more uniform emergence, enabling plants to establish quickly and compete effectively with weeds or withstand initial periods of moisture deficit. Moreover, seed health—assured through rigorous certification processes—minimizes the risk of seedborne diseases, which can otherwise compromise early growth stages and reduce resilience throughout the season. These factors directly enhance a plant’s capacity to cope with environmental fluctuations, thereby reducing yield losses under stress conditions. In this way, certified seed becomes not just a yield-enhancing input but also a strategic component of climate-resilient farming systems.

Modern plant varieties are characterized not only by higher yield potential, but also by better adaptation to unfavorable climate and soil conditions, resistance to diseases and quality of raw material. Their use, in combination with certified seed material, can result in increased productivity and greater yield stability.

Numerous studies show that the use of certified seed material leads to a significant increase in yields. This has been demonstrated, among others, in rice crops [8,9], wheat [10] or maize [11]. In Tanzania, it was shown that the use of certified cassava seeds contributed to the reduction of viral diseases and an increase in yield by 80.6% compared to uncertified material. The additional income was over USD 2279/ha, with a seed purchase cost of USD 153/ha [12].

In turn, unqualified material, often from previous harvests or improper storage, is a potential source of infection. These seeds can be infected with fungal and viral pathogens, and their germination capacity is often reduced. The lack of genotypic uniformity results in high variability within plants: differences in ripening time, resistance, plant size, or crop quality make crop management difficult and increase production costs.

Despite the documented benefits, the share of certified seed in Poland remains low. In 2023, the average share of certified seed in cereal crops was 20.4%, and after taking into account mixtures, 19.3%. Although a slight upward trend is noticeable, this level remains significantly lower than in many Western European countries. For comparison, in Germany, France and Denmark, the share of certified seed exceeds 50–60%, and in some crops, such as wheat or barley, it reaches even 80% [13]. Also, in developing countries, activities are being carried out to promote the use of certified seeds as an element of combating low agricultural productivity.

The low share of certified seeds in Poland may result from a combination of economic barriers, limited access to knowledge, and insufficient agricultural policy incentives. Among the key economic constraints are the perceived high cost of certified seed relative to farm-saved seed, especially in the context of uncertain market prices and variable yields. Additionally, the benefits of certified seeds—such as yield stability and reduced disease risk—are often realized over time and may not be immediately apparent, reinforcing reluctance to invest. From a policy perspective, current support mechanisms for certified seed use are either limited in scope or poorly targeted. Subsidies may not adequately compensate for the price differential, and advisory services may lack the capacity to effectively promote the long-term agronomic and economic benefits of certified seed use.

Cereal production is of key importance to both Polish agriculture and the international market. Poland is one of the leading cereal producers in the European Union and is the world’s largest producer of triticale. Cereals cover approximately 5.5 million hectares, including wheat (ca. 2.2 million ha), triticale (ca. 1.2 million ha), and barley (ca. 0.7 million ha). Given the economic and export significance of cereals, as well as growing challenges related to their sustainable and efficient production, research in this field is both necessary and internationally relevant.

The aim of this study was to compare the yield level, its variability and stability in the cultivation of three cereal species: spring barley, winter triticale and winter wheat, in temperate climate conditions. The analysis was carried out based on data obtained from surveys conducted on farms in Poland.

2. Materials and Methods

2.1. Survey Data

Surveys were conducted on farms located in Poland, representing six diverse agroecological regions (Figure 1). In order to reflect the agroecological diversity of Poland, each farm was assigned to one of six agroecological regions, defined based on soil and climatic conditions and the territorial layout of the country. This division, developed in accordance with the methodology of Studnicki et al. [14], enabled a spatial analysis of yield variability and stability in the environmental and management context. The general characteristics, including weather data, of these six agroecological regions are presented in Table S1 in the Supplemental Material.

The data came from questionnaires developed (Appendix A) and distributed as part of the cooperation between the Plant Breeding and Acclimatization Institute—National Research Institute (IHAR–PIB) based in Radzików and the Regional Agricultural Advisory Centers (ODR). The research was carried out in 2021–2023. The farms were randomly selected from those using Regional Agricultural Advisory Centers (ODR) services, maintaining the representation of agroecological regions. The analysis included only farms conducting agricultural accounting, which ensured high quality, reliability and consistency of the data obtained.

Each record in the database referred to one specific farm. The collected empirical material—hereinafter referred to as the survey data set—contained over 8000 records from all six agroecological regions, covering the three most commonly grown cereal species in Poland: winter wheat (Triticum aestivum L.), winter triticale (× Triticosecale Wittm. ex A. Camus), and spring barley (Hordeum vulgare L.).

The questionnaire contained detailed questions regarding:

• Location, area and type of farm;
• Soil quality class, pH and previous crop;
• Type and degree of seed certification;
• Sowing practices, fertilization, and use of plant protection products;
• Yields obtained (expressed in t/ha);
• Sociodemographic data (age and education of the person managing the farm).

Such a broad and diverse sample enabled not only the analysis of yield levels, but also the study of yield variability and stability in relation to the seed material used and agrotechnical practices.

2.2. Statistical Analysis

The collected data were first subjected to a preliminary qualitative assessment, in which their completeness and correctness were checked. Records from the respondent database that were incomplete were removed from further analysis. Then, the extreme studentized deviation test (Grubbs’ extreme values test) was used to exclude outliers that could interfere with further analysis of the results.

The Student’s t-test with Welch’s correction was used to compare the average yields of farms using certified seeds with farms that did not use them. To compare yields in regions, we used ANOVA with Tukey’s post hoc test. The stability of yields in the analyzed farms was assessed using the Shukla stability parameters and Wricke’s ecovalence. In order to compare the significance of differences in the number of farm managers with higher education and farms with an area larger than 50 ha, we used the Chi-square test. All statistical calculations were performed using the R environment, version 4.4.2, at the significance level of α = 0.05.

3. Results

In the study area, based on the survey research, the following average yields were obtained for winter wheat: 6.04 t ha⁻¹ (standard deviation 1.41), for winter triticale: 4.87 t ha⁻¹ (standard deviation 1.19), and for spring barley: 4.47 t ha⁻¹ (standard deviation 1.22). For winter wheat, 65.95% of the surveyed farms, as shown in

Table 1. Mean yields of three cereal species depending on seed certification.

	Winter Wheat		Winter Triticale		Spring Barley
	Certified Seed	Non-Certified Seed	Certified Seed	Non-Certified Seed	Certified Seed	Non-Certified Seed
n (%)	2748 (65.9%)	1422 (34.1%)	1004 (51.9%)	932 (48.1%)	842 (56.1%)	660 (43.9%)
Mean (t ha−1)	6.26	5.62	4.93	4.78	4.59	4.29
Standard deviation	1.42	1.35	1.24	1.20	1.25	1.18
Coefficient of variation	2.28	2.40	2.52	2.51	2.73	2.76
Yield Increase (%)	11.4		3.1		7.0
t-test p-Value *	<0.0001		<0.0001		<0.0001

* p-Values < 0.05 indicate significant yield differences between certified and non-certified seed.

. Farms using certified seed had a significantly higher yield of winter wheat (6.26 t ha⁻¹) than those using non-certified seed (5.62 t ha⁻¹), with a yield increase of 11.4%.

For winter triticale, 51.9% of the surveyed farms used certified seed similar to wheat, and we observed a significant difference in the yield between farms using certified seed (4.93 t ha⁻¹) and non-certified seed (4.78 t ha⁻¹), with a yield increase of 3.1%. Among the surveyed farms growing spring barley, 56.1%; we also found a significantly higher yield in these farms (4.59 t ha⁻¹) than those using non-certified seed (4.29 t ha⁻¹), with a yield increase of 7.0%. For winter wheat, we observed lower values of the coefficient of variation for yield in farms using certified seed material than in those that did not use it (CV: 22.8% vs. 24.0%). For the other two species, the differences for the coefficient of variation were not large; even for winter wheat, values were slightly higher for certified seed users than for farms using non-certified seed material (Table 1).

For wheat in all agroecological regions, we observed significant differences between average grain yields and the use of certified and non-certified seed material (

Table 2. Grain yield of the studied cereal species in individual agroecological regions.

Agroecological Regions	Winter Wheat			Winter Triticale			Spring Barley
	Certified Seed Yield (t ha−1)	Non-Certified Seed Yield (t ha−1)	p Value *	Certified Seed Yield (t ha−1)	Non-Certified Seed Yield (t ha−1)	p Value *	Certified Seed Yield (t ha−1)	Non-Certified Seed Yield (t ha−1)	p Value *
Region 1	6.36c #	4.21a	<0.0001	4.57a	4.18a	0.0482	4.23b	3.96a	0.2391
Region 2	6.57d	6.29e	0.0085	5.43d	5.18e	0.0002	4.52c	4.17b	<0.0001
Region 3	5.87a	5.52c	0.0124	5.11c	5.11d	0.6915	4.08a	4.26c	0.6761
Region 4	5.97b	5.38b	<0.0001	4.92b	4.57b	0.0044	4.35b	4.13b	0.0577
Region 5	6.57d	5.65d	<0.0001	4.94b	4.64b	0.1394	5.12e	4.18b	<0.0001
Region 6	5.91a	5.54c	<0.0001	4.94b	4.78c	0.0372	4.66d	4.62d	0.0715

* p-Values < 0.05 indicate significant yield differences between certified and non-certified seed within region and species; # different letters indicate significant differences at α = 0.05 in yield between regions.

). The largest difference was observed for Region I—approximately 2 t ha⁻¹. For the use of certified seed material, the highest yield was observed in regions II and V (6.57 t ha⁻¹), and the lowest yield in region III (5.87 t ha⁻¹). In the case of the use of non-certified seed material, the highest yield was observed in Region II, 6.29 t ha⁻¹, and the lowest in Region I, 4.21 t ha⁻¹. We did not observe significant yield differences between certified and uncertified farms for winter triticale in regions III and IV. For farms using certified and non-certified seed material, the highest triticale yield was observed in region II (5.43 t ha⁻¹ and 5.18 t ha⁻¹, respectively). For barley, no significant difference was observed between the average yield of certified and non-certified seed material in regions I, III, and IV. The largest difference between the yield obtained on farms using certified and non-certified seed material was observed in region V, amounting to approximately 1 t ha⁻¹. For farms using certified seed material, the highest barley yield was observed in agroecological region V (5.12 t ha⁻¹), while farms using non-certified seed material in region IV (4.18 t ha⁻¹). The number of farms using or not using certified seed in individual regions is presented in Table S2 in the Supplementary Material.

Table 3. Characteristic of farms in six agroecological regions for those who use and do not use certified seeds.

Species	Region	Certified Seed (Yes/No)	Seed Dressing (% Farms)	Herbicide (% Farms)	Fungicide (% Farms)	Insecticide (% Farms)	Number of Pesticide Treatments (n)	N Fertilization (kg ha−1)	Age (Years)	Higher Education (% Managers)	p Value *	Farm Area > 50 ha (% Farms)	p Value *
Winter Wheat	I	No	92%	100%	96%	67%	3	133	47.8	15%	0.0018	69%	0.8938
	I	Yes	99%	100%	100%	77%	3.1	143.4	47.8	24%		71%
	II	No	85%	97%	85%	48%	2.2	131.2	45.8	36%	<0.0001	30%	<0.0001
	II	Yes	96%	100%	99%	64%	2.7	137.4	46.6	19%		48%
	III	No	95%	99%	92%	46%	2.4	129	47.3	8%	0.0027	42%	0.9288
	III	Yes	92%	98%	94%	57%	2.8	137.4	45.7	17%		43%
	IV	No	93%	100%	89%	53%	2.3	117	45.2	28%	0.8471	15%	<0.0001
	IV	Yes	90%	100%	98%	69%	3.1	130.4	45.7	29%		26%
	V	No	85%	100%	97%	65%	3	143.1	47.4	18%	0.5361	43%	<0.0001
	V	Yes	91%	99%	86%	58%	2.5	128.9	48.2	14%		27%
	VI	No	94%	98%	80%	41%	2.1	103.4	40.9	18%	0.9281	21%	0.0083
	VI	Yes	97%	100%	90%	52%	2.5	114.9	44.2	17%		28%
Winter Triticale	I	No	60%	98%	73%	35%	2	100.3	45.4	12%	0.0014	37%	0.3416
	I	Yes	98%	100%	65%	26%	1.5	106.5	45.5	6%		41%
	II	No	81%	98%	66%	8%	1.1	100	47.9	15%	<0.0001	31%	0.9261
	II	Yes	88%	99%	78%	13%	1.3	105.7	49	22%		30%
	III	No	82%	97%	79%	27%	1.8	99.2	44.9	12%	0.9282	21%	0.0128
	III	Yes	85%	98%	83%	33%	1.9	103.6	45.5	11%		29%
	IV	No	85%	97%	64%	11%	1.1	86.2	42.7	25%	0.1028	8%	0.0231
	IV	Yes	96%	100%	71%	22%	1.5	96.1	45.3	29%		15%
	V	No	88%	99%	54%	17%	1.1	87.3	48.8	10%	0.7182	19%	0.0019
	V	Yes	90%	100%	70%	21%	1.4	93	47.3	12%		27%
	VI	No	83%	97%	45%	18%	1.1	77.2	42.7	27%	<0.0001	5%	0.9352
	VI	Yes	88%	98%	50%	11%	1	85.4	40.6	15%		4%
Spring Barley	I	No	48%	100%	64%	18%	3.2	87.8	48.7	6%	0.4511	33%	0.0029
	I	Yes	87%	100%	57%	12%	3.2	90.5	46.9	8%		38%
	II	No	66%	98%	31%	4%	2.6	88.2	49.5	15%	<0.0001	24%	0.0031
	II	Yes	83%	98%	68%	29%	3.6	95.5	47.9	25%		27%
	III	No	89%	97%	72%	21%	3.4	87	47.7	11%	0.0034	15%	0.0173
	III	Yes	91%	98%	79%	39%	3.9	90.9	45.6	16%		19%
	IV	No	91%	98%	57%	23%	3.2	83.4	45	20%	<0.0001	13%	0.0012
	IV	Yes	94%	99%	70%	29%	4.1	84.9	45.3	31%		9%
	V	No	85%	99%	57%	8%	3	80.5	45.8	14%	0.0372	38%	<0.0001
	V	Yes	92%	99%	84%	40%	4.2	88.8	47.5	11%		44%
	VI	No	85%	99%	64%	11%	3.3	66.9	40.9	21%	0.0073	16%	<0.0001
	VI	Yes	91%	100%	63%	16%	3.4	86	41.6	18%		22%

* p-Values < 0.05 indicate significant proportion differences between certified and non-certified seed.

presents the basic characteristics of farms in individual regions for the considered cereal species, using and not using certified seed material. For winter wheat, in most regions we can see more frequent use of various types of plant protection products, greater N fertilization and often we can find farms with a total area of more than 50 ha in farms using certified seed material, the exception being region V. The age of people running the farm in individual regions does not differ significantly between those using certified material and those not using such material. The greatest age difference was observed for region VI, where, on average, younger people run farms not using certified seed material. We generally observed a higher frequency and number of plant protection treatments in farms using certified seed material for winter triticale. The exception is region I, where for the percentage of fungicide, insecticide, and the number of all plant protection treatments, we observed higher values for farms not using qualified seed. For all regions, we observed higher average nitrogen fertilization in farms using qualified seed. The share of large farms (over 50 ha) is significantly higher for those using qualified seed in regions I, III, IV, and V, while it was at a similar level in the remaining regions. For spring barley, similar to winter triticale, we observed a higher frequency and number of different plant protection treatments in farms using certified seed, except for region I, where the use of fungicides, insecticides, and the total number of plant protection treatments were lower. We also observed higher N fertilization rates for this species in certified seed farms. In regions V and VI, we observed a greater share of people running farms with higher education on farms that do not use seed material. For winter wheat in regions V, I, and VI, they were not significantly different. In contrast, it was the opposite in the remaining regions.

Table 4. Values of yield stability parameters in individual regions on farms using and not using certified seed.

Region	Certified Seed	Winter Wheat		Winter Triticale		Spring Barley
		Shukla’s Variance (Rank *)	Ecovalence (Rank)	Shukla’s Variance (Rank)	Ecovalence (Rank)	Shukla’s Variance (Rank)	Ecovalence (Rank)
I	No	74.6 (12)	4072 (12)	17.9 (9)	1031 (9)	34.5 (11)	2781 (11)
I	Yes	4.04 (2)	309 (2)	10.5 (5)	632 (5)	57.6 (12)	4550 (12)
II	No	14 (8)	842 (8)	23.2 (12)	1314 (12)	16.8 (7)	1422 (7)
II	Yes	11.6 (7)	714 (7)	8.82 (3)	544 (3)	19.5 (9)	1634 (9)
III	No	31.4 (11)	1770 (11)	13.5 (7)	793 (7)	10.4 (5)	936 (5)
III	Yes	23.7 (10)	1360 (10)	19.3 (10)	1104 (10)	12.9 (6)	1126 (6)
IV	No	8.92 (6)	570 (6)	22.9 (11)	1295 (11)	5.13 (3)	530 (3)
IV	Yes	0.369 (1)	114 (1)	3.89 (1)	282 (1)	3.84 (2)	431 (2)
V	No	6.47 (3)	439 (3)	10.1 (4)	612 (4)	7.24 (4)	691 (4)
V	Yes	8.74 (5)	560 (5)	12.2 (6)	725 (6)	3.33 (1)	391 (1)
VI	No	7.18 (4)	477 (4)	17.2 (8)	994 (8)	19.1 (8)	1599 (8)
VI	Yes	20.3 (9)	1177 (9)	7.36 (2)	467 (2)	22.7 (10)	1873 (10)

* Rank (1 = highest stability, 12 = lowest stability).

presents the values of Shukla and Wricke’s ecovalence stability variance for the studied regions in farms using and not using certified seed for the three studied species. We observe a high agreement between Shukla and Wricke’s ecovalence parameters within the species considered. For winter wheat in regions I, II, III, and IV, we observed higher yield stability (lower values of the stability parameters used) in those farms that used certified seed. On the other hand, in regions V and VI, the farms that did not use certified seed had higher yield stability. The most stable yield (the lowest parameter value) is observed in Region IV when using certified seed, and the least stable yield is observed in Region I when using non-certified seed. For winter triticale, only for region V, we observe lower yield stability when non-certified seed was used; the remaining regions have greater stability when certified seed was used. As with winter wheat, the highest stability is observed in Region IV when using certified seed. When using certified seed, we observe higher yield stability for spring barley only in two regions, IV and V. The highest degree of yield stability is observed in region V.

4. Discussion

The results of the conducted studies confirm that the use of certified seed material has a significant impact on the size and stability of cereal yields cultivated in temperate climate conditions. In all analyzed species (winter wheat, winter triticale and spring barley), farms using certified material achieved higher yields than farms using uncertified material. These differences were statistically significant and are confirmed in studies conducted in other climate zones for wheat [10]. However, such a significant difference was also observed for rice [10,15,16] and canola [17].

The use of certified seed material also had a positive effect on yield stability, which is confirmed by lower values of Shukla variance and Wricke ecovalence, especially in region IV for all tested cereal species. Region IV is characterized by the lowest share of fertile arable land among all regions. In this case, plants are more susceptible to biotic and abiotic stresses. As can be seen, the use of certified seed significantly reduces yield variability and makes cereal production more predictable. In Region VI, however, we observe a different trend: farms not using certified seed demonstrate higher yield stability. Region VI is characterized by the smallest average farm sizes and a high degree of fragmentation in agricultural production, often involving mixed cropping systems and diversified, low-input farming practices. In such a context, the benefits of certified seed—typically optimized for monoculture and intensive production—may not translate effectively. Moreover, smaller farms in fragmented systems may rely more heavily on traditional knowledge, local seed varieties adapted to microclimatic conditions, and risk-minimizing practices developed over generations. The stability is of particular importance in the context of increasing climate change and the increasing frequency of extreme weather events, which destabilize traditional models of agricultural production. In this context, investment in certified material may be one of the key elements of the risk management strategy in agriculture and counteracting the negative effects of climate change.

Analysis of socioeconomic data suggests that farms using certified seed were more often managed by individuals with higher levels of education. This correlation may reflect greater awareness, openness to innovation, and improved access to agronomic knowledge among better-educated farmers. Although age differences among farm managers were less pronounced, indicating that the decision to adopt certified seed is influenced more by educational and economic factors than by farming or life experience, this finding has broader implications. Specifically, the link between education, larger farm size, and adoption of certified seed highlights the need for targeted extension services and policy interventions. For instance, support schemes and tailored outreach programs may be necessary to assist smaller-scale and less-educated farmers, ensuring they are not excluded from the benefits of modern inputs due to structural disadvantages. Policymakers and development agencies should consider these socioeconomic barriers when designing strategies to promote the adoption of certified seed more equitably across diverse farming populations.

The study also has some methodological limitations. First, the data were collected using a survey method, which may be associated with declarative errors and difficulties in precisely estimating yields by respondents. Second, the lack of detailed data on cereal varieties makes it impossible to separate the impact of a specific variety from the mere fact of using certified seeds. Additionally, the cooccurrence of other production factors (such as fertilization or chemical plant protection) could have partially influenced the obtained results.

Compared to other European countries, the share of certified seed in Poland remains low, approximately 20%, while in Germany, France or Denmark it exceeds 50–60% [13]. This phenomenon indicates the need for actions supporting the development of the seed market in Poland. Promoting the use of certified seed should be an element of a sustainable agriculture strategy that responds to the challenges related to food security, climate change and the need to increase the efficiency and profitability of crop production.

5. Conclusions

These studies confirm that the use of certified seed contributes to an increase in the level and stability of cereal yields in temperate climate conditions. Farms using certified seed obtained statistically significantly higher yields for all species analyzed—winter wheat, winter triticale and spring barley. A positive effect of certified seed on yield stability was also observed, which is particularly important in the context of climatic variability and the risk of extreme weather conditions. Additionally, the analysis of socioeconomic factors shows that farms using certified seed were more often run by people with higher education and were characterized by a higher level of production intensification, including more frequent use of fertilization and plant protection products. This may indicate a synergistic effect of biological and technological progress on the efficiency of plant production. The use of certified seed should be treated as a strategic element of modern, sustainable agriculture, responding to contemporary challenges related to climate, food quality and production safety.