Resistance of Winter Triticale Cultivars as a Key Determinant of Their Agricultural Use

Abstract

Triticale (×Triticosecale) is an important cereal crop in Poland, valued for its high yield potential and tolerance to biotic and abiotic stresses; however, fungal diseases remain a major constraint to production. This study aimed to assess the resistance and yield performance of selected winter triticale cultivars under varying levels of chemical crop protection across diverse environmental conditions. Field experiments were conducted during the 2023/2024 and 2024/2025 growing seasons at 16 locations in Poland within the framework of Post-Registration Variety Testing (PRVT). Three cultivars (Medalion, Fanfaro, and SU Atletus) were evaluated under two agrotechnical levels differing in fertilization and protection intensity. Disease severity for powdery mildew, brown rust, and septoria leaf blotch was assessed using a 9-point scale, and yield data were analyzed using four-way ANOVA and multivariate methods. The results demonstrated significant effects of management intensity, cultivar, growing season, environment as well as interactions: management intensity × environment, cultivar × environment, growing season × environment, management intensity × growing season × environment and cultivar× growing season × environment were significant for all four traits of the study. Management intensity × cultivar as well as management intensity × cultivar × environment interactions were significant for powdery mildew, brown rust and septoria leaf blotch. Management intensity × growing season interaction was significant for powdery mildew and septoria leaf blotch. Management intensity × cultivar × growing season × environment interaction was significant for powdery mildew and brown rust. The cultivar × growing season interaction was significant only for brown rust and management intensity × cultivar × growing season interaction for septoria leaf blotch. Increased protection intensity generally reduced disease severity and improved yield. Medalion exhibited the highest yield stability, whereas SU Atletus achieved the highest yields under favorable conditions but with greater variability. Fanfaro showed intermediate performance. The findings highlight the importance of cultivar selection and management intensity in optimizing triticale production and support the role of PRVT in guiding agricultural practice under variable climatic conditions.

1. Introduction

Triticale (×Triticosecale) is one of the most important cereal species cultivated in Poland, combining favorable traits of wheat (Triticum spp.) and rye (Secale cereale). These include high yield potential, good adaptation to diverse environmental conditions, and a relatively high tolerance to environmental stresses [1]. Triticale also exhibits greater resistance to diseases and soil acidity than wheat, as well as an enhanced tolerance to abiotic stresses such as drought and frost [2,3,4,5,6]. Due to these characteristics, triticale is widely used in feed production, and in recent years there has been a growing interest in its use in alternative farming systems, including organic and low-input agriculture [2,6].

Triticale is the third most commonly cultivated cereal in Poland, after wheat and maize. In 2025, the area under triticale cultivation exceeded 1.1 million hectares, while grain yields averaged approximately 4.8 t/ha [7]. Currently, Poland is the largest producer of triticale in the European Union. Triticale cultivars bred in Poland are characterized by high productivity and account for 70–80% of the global cultivation area of this crop [8].

Under field conditions, one of the main factors limiting triticale yield is fungal diseases, which cause losses in both the quantity and quality of grain. Among the most important pathogens is powdery mildew (Blumeria graminis), which is manifested by a white-grey, powdery growth on leaves and stems, reducing photosynthetic activity and weakening the plants. Brown rust (Puccinia recondita) leads to the formation of brown urediniospores on leaf surfaces, thereby decreasing the assimilative area and reducing grain yield [9,10]. Septoria leaf blotch (Zymoseptoria tritici) causes necrotic lesions on leaves and their premature senescence, which further limits the photosynthetic capacity of plants [11,12,13,14].

Infections by these pathogens result not only in yield reduction but also in deterioration of grain quality; therefore, effective control of fungal diseases is one of the key elements of triticale crop management [15,16]. Consequently, the selection of resistant cultivars adapted to local environmental conditions, as well as the implementation of Post-Registration Variety Testing (PRVT) conducted under multi-environmental conditions, are essential to ensure yield stability and high-quality harvests.

Breeding progress leads to the continuous introduction of new cultivars into agricultural practice, differing in yield potential, morphological traits, disease resistance, and responses to environmental conditions and agronomic practices. In this context, PRVT plays a crucial role, as its primary objective is the objective evaluation of the agronomic value of cultivars under field conditions that closely reflect commercial production systems. The PRVT system enables the comparison of cultivars across multi-environment and multi-year trials, allowing for the identification of genotypes characterized by high yield stability and optimal adaptation to regional conditions.

Post-registration trials constitute an important source of information for both agricultural practice and advisory services, supporting the rational selection of cultivars suited to specific site conditions and cropping systems [17,18,19]. They also allow for the analysis of genotype × environment interactions, which significantly determine the variability of yield and agronomic traits of triticale across years and regions of the country [20]. Under conditions of ongoing climate change and increasing weather variability, the importance of such studies continues to grow.

PRVT is an essential component of the system for evaluating and implementing biological progress in agriculture. This system has been developed and is coordinated by the Research Centre for Cultivar Testing (RCCT) in Słupia Wielka, which aligns national variety testing with market-oriented agricultural conditions and the requirements of the European Union [18]. In summary, PRVT plays a key role in transferring knowledge from science to agricultural practice. It enables rational cultivar selection, increases production efficiency, and allows for better adaptation of crop cultivation to local environmental conditions, which is of particular importance in modern agriculture.

In light of the requirements of the European Green Deal (EGD), Integrated Pest Management (IPM) is a key component of sustainable agricultural production. Restrictions on the use of chemical plant protection products necessitate the application of alternative methods, such as the selection of resistant cultivars, monitoring of pests and diseases, and the integration of biological and agronomic strategies. The implementation of IPM makes it possible to minimize yield losses while simultaneously reducing pesticide residues in the environment and in food. These solutions also contribute to improving biodiversity, yield stability, and the resilience of production systems to variable climatic conditions [21].

In integrated crop production, the selection of appropriate cultivars is of great importance. For many years, the RCCT has recommended the introduction of varieties showing at least moderate resistance or tolerance to pests and diseases into cultivation. The annually published Variety Descriptive Lists (VDL) contain information on yield performance and other important agronomic and utility traits of cultivars, including their resistance to the most important diseases, as well as a list of cultivars entered in the National Register (NR) and descriptions of cultivars newly introduced in a given year. Data on the level of cultivar resistance are also available from the results of trials conducted within the framework of the PRVT [22]. Cultivars best adapted to specific soil and climatic conditions are subsequently included in the List of varieties recommended for cultivation within the territory of the Voivodeship for a given voivodeship [23]. The withdrawal of many active substances used in plant protection products in the European Union makes the rapid introduction of new cultivars resistant and tolerant to pests and diseases increasingly necessary, in line with the principles of integrated pest management. An increase in the number of such cultivars is expected in the coming years. Equally important is the tolerance of cultivars to abiotic stress factors, such as drought or frost [24,25]. The aim of the study was to assess the resistance of different winter triticale cultivars under varying levels of chemical crop protection intensity in Poland. The susceptibility of the cultivars to diseases such as powdery mildew (B. graminis), brown rust (P. recondita), and septoria leaf blotch (Z. tritici) was evaluated. The research results constitute a valuable source of information for the selection of cultivars for specific farming conditions in terms of protection intensity, as well as for their choice under different soil conditions. An additional challenge for agricultural practice is the conclusion of the EU–Mercosur partnership agreement in December 2024. This represents a serious challenge for European agricultural producers, who will have to compete with countries that have access to a much broader arsenal of plant protection products. In the context of the progressive restriction of pesticide availability in the EU and the growing pressure from producers in countries with far greater chemical protection options, careful selection of crop varieties with increased resistance to diseases and pests becomes critically important. The use of conventional plant protection products alone will prove insufficient; therefore, it will be necessary to implement an integrated approach combining agronomic practices—such as crop rotation, appropriate sowing dates, and optimal seeding density—with biological methods and other alternative crop protection tools. Meeting the challenge posed by the Mercosur agreement thus requires a systemic rethinking of agricultural production strategies in Europe, based on a holistic approach to plant protection that goes far beyond traditional chemical methods [26].

The aim of the study was to assess the resistance of different winter triticale cultivars under varying levels of chemical crop protection intensity in Poland. The susceptibility of the cultivars to diseases such as powdery mildew (B. graminis), brown rust (P. recondita), and septoria leaf blotch (Z. tritici) was evaluated. The research results constitute a valuable source of information for the selection of cultivars for specific farming conditions in terms of protection intensity, as well as for their choice under different soil conditions.

The research hypotheses assumed that the intensity of chemical protection, the cultivar, the year of the study, and the location of the experiments had no effect on yield performance or the health status of winter triticale.

2. Materials and Methods

2.1. Experimental Sites of the Conducted Study

The research results were obtained from field experiments conducted at sixteen experimental sites (one in each voivodeship), including fifteen sites belonging to the RCCT: Variety Testing Station (VTS) in Chrząstowo, Głubczyce, Pawłowice, Seroczyn, Słupia, Sulejów, Świebodzin, Węgrzce, Wrócikowo, Variety Testing Department (VTD) in Dukla, Marianowo, Radostowo, Rarwino, Tarnów, Uhnin and at Agricultural Experimental Station (AES) belonging to Institute of Plant Protection—National Research Institut (IPP—NRI) (Figure 1).

Observations were carried out over two growing seasons, i.e., 2023/2024 and 2024/2025. The subject of the study was winter triticale (×Triticosecale). The experiments were conducted within the framework of the PRVT, in accordance with the “Methodology for testing the value for cultivation and use of cereal varieties” [27].

Three winter triticale cultivars were selected for the analysis: Medalion, Fanfaro, and SU Atletus. In the analyzed growing seasons, these cultivars served as standards in PRVT.

The experimental sites:

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VTS Pawłowice—voivodeship: śląskie, county: Gliwice (φ = 50°28′, λ = 18°29′, H = 240 m a.s.l.). Agricultural land suitability complexes of soils: good wheat. Soil bonitation classes: IIIa, IIIb.

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VTS Chrząstowo—voivodeship: kujawsko-pomorskie, county: Nakło nad Notecią (φ = 53°11′, λ = 17°35′, H = 10 m a.s.l.). Agricultural land suitability complexes of soils: good wheat. Soil bonitation classes: IIIb, IIIa.

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VTS Głubczyce—voivodeship: opolskie, county: Głubczyce (φ = 50°11′, λ = 17°50′, H = 280 m a.s.l.). Agricultural land suitability complexes of soils: very good wheat. Soil bonitation classes: II.

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VTS Seroczyn—voivodeship: mazowieckie, county: Siedlce (φ = 52°00′, λ = 21°56′, H = 150 m a.s.l.). Agricultural land suitability complexes of soils: very good rye, good rye. Soil bonitation classes: IIIb, IVa.

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VTS Słupia—voivodeship: świętokrzyskie, county: Jędrzejów (φ = 50°38′, λ = 19°58′, H = 290 m a.s.l.). Agricultural land suitability complexes of soils: good wheat. Soil bonitation classes: IIIa.

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VTS Sulejów—voivodeship: łódzkie, county: Piotrków Trybunalski (φ = 51°21′, λ = 19°52′, H = 188 m a.s.l.). Agricultural land suitability complexes of soils: good wheat. Soil bonitation classes: IIIb.

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VTS Świebodzin—voivodeship: lubuskie, county: Świebodzin (φ = 52°14′, λ = 15°35′, H = 90 m a.s.l.). Agricultural land suitability complexes of soils: very good rye. Soil bonitation classes: IIIb, IIIa.

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VTS Węgrzce—voivodeship: małopolskie, county: Kraków (φ = 50°07′, λ = 19°59′, H = 285 m a.s.l.). Agricultural land suitability complexes of soils: very good wheat. Soil bonitation classes: II.

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VTS Wrócikowo—voivodeship: warmińsko-mazurskie, county: Olsztyn (φ = 53°49′, λ = 20°40′, H = 142 m a.s.l.). Agricultural land suitability complexes of soils: good wheat. Soil bonitation classes: IIIb.

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VTD Dukla—voivodeship: podkarpackie, county: Krosno (φ = 49°34′, λ = 21°41′, H = 324 m a.s.l.). Agricultural land suitability complexes of soils: mountain cereal soil complex. Soil bonitation classes: IVb.

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VTD Marianowo—voivodeship: podlaskie, county: Łomża (φ = 53°13′, λ = 22°07′, H = 140 m a.s.l.). Agricultural land suitability complexes of soils: very good rye. Soil bonitation classes: IIIb, IVa.

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VTD Radostowo—voivodeship: pomorskie, county: Tczew (φ = 53°59′, λ = 18°45′, H = 40 m a.s.l.). Agricultural land suitability complexes of soils: very good wheat, good wheat. Soil bonitation classes: II.

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VTD Rarwino—voivodeship: zachodniopomorskie, county: Kamień Pomorski (φ = 53°56′, λ = 14°50′, H = 10 m a.s.l.). Agricultural land suitability complexes of soils: good rye. Soil bonitation classes: IVa.

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VTD Tarnów—voivodeship: dolnośląskie, county: Ząbkowice Śląskie (φ = 50°35′, λ = 16°47′, H = 300 m a.s.l.). Agricultural land suitability complexes of soils: very good wheat. Soil bonitation classes: IIIa.

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VTD Uhnin—voivodeship: lubelskie, county: Parczew (φ = 51°34′, λ = 23°02′, H = 157 m a.s.l.). Agricultural land suitability complexes of soils: very good rye. Soil bonita-tion classes: IVa.

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AES Winna Góra—voivodeship: wielkopolskie, county: Środa Wielkopolska (φ = 52°12′, λ = 17°26′, H = 86 m a.s.l.). Agricultural land suitability complexes of soils: good wheat. Soil bonitation classes: IIIa.

The experiments were most frequently conducted on soil belonging to the good wheat, very good rye, and very good wheat suitability complexes. Land quality classes IIIa, IIIb, and IVa were predominant.

2.2. Levels of Agricultural Technology Applied in the Experiments

The experiments were carried out under two levels of agrotechnical management: standard (a1) and high (a2). The high agrotechnical level differed from the standard one by an additional nitrogen fertilization of 40 kg/ha (

Table 1. Treatments performed at agrotechnical levels.

Treatment	Management Levels
	a1	a2
Nitrogen fertilization (kg N/ha)	+	a1 + 40
Growth regulators		+
Fungicide treatments
- first treatment (stem and leaves protection)		+
- second treatment (leaves and ear protection)		+
Foliar fertilization		+

a1—standard management level, a2—high management level.

).

Growth regulators were applied to prevent lodging and were used when all plants were at the same developmental stage. The dose was often split and applied at different times. In some cases, due to the occurrence of drought or poor crop condition, the treatment was omitted. Growth regulators were applied from March to May.

Fungicide treatments were applied two times: the first aimed at controlling stem base diseases (eyespot) and leaf diseases, while the second targeted leaf and ear diseases (at the heading stage or later). The second treatment was carried out using a different active substance than that used in the first application. Registered plant protection products approved for winter triticale were used in accordance with label recommendations. At the a2 level, foliar fertilization with multi-nutrient preparations was also applied. Under unfavorable weather conditions (e.g., drought), the application of preparations (multi-nutrient fertilizers and growth regulators) was omitted.

Disease severity was assessed on a 1.0–9.0° scale, where 9.0° indicated a healthy plant with no disease symptoms and 1.0° indicated a plant completely infected by pathogens. This scoring system follows the methodology used in the Polish Post-Registration Variety Testing (PRVT) program [25]. A score of 9.0 should not be interpreted as immunity, but rather as the highest level of resistance observed under field conditions. Observations for cultivars were conducted on all replications. In two-factor experiments, disease assessments at the a1 level were carried out for all cultivars, whereas at the a2 level they were performed only for reference cultivars [27]. Observations were made regularly from the appearance of the first disease symptoms. Assessments were performed during the period of the highest disease severity.

Nitrogen, phosphorus, and potassium fertilization was applied in the experiments, and foliar fertilization with multi-nutrient fertilizers was also used. Each year before the establishment of the experiment, soil samples were collected to determine soil pH and the content of available macronutrients—phosphorus (P, P₂O₅), potassium (K, K₂O), and magnesium (Mg, MgO)—in order to define fertilization requirements for a given experiment. Chemical analyses determining soil nutrient status were performed by Regional Agrochemical Laboratories. The adopted fertilization rates were applied to the entire experimental block. Fertilizers were spread parallel to the direction of plots before ploughing for sowing.

The most common preceding crops for triticale experiments were winter oilseed rape (Winna Góra, Chrząstowo, Pawłowice, Radostowo, Sulejów, Świebodzin, Tranów, Uhnin, Węgrzce) and grain legumes (Słupia, Rarwino, Seroczyn, Wrócikowo). Cereals were also used as preceding crops (Dukla, Marianowo), and at one experimental site (Głubczyce) sugar beet was used. The harvest plot area was 16.5 m².

The type and number of post-harvest tillage operations depended on the preceding crop, soil tilth, and soil compaction, as well as on the course of the disease. The depth of ploughing for sowing ranged from 20 to 25 cm. Ploughing was carried out parallel to the experimental strips and perpendicular to the plots. The type and frequency of pre-sowing tillage operations were adjusted each time to the soil condition.

The sowing material consisted of selected winter triticale cultivars chosen from all cultivars among those designated for PRVT experiments. In the experiments, seeds were treated with the seed dressing Gizmo 060 FS, containing tebuconazole (a triazole group compound) as the active substance at a concentration of 60 g/L (5.67%).

Plant protection treatments were applied at both the a1 and a2 levels. Treatments were carried out from two-meter-wide paths between experimental strips using sprayers. Weed infestation was controlled with herbicides, with the choice of products and the number of applications depending on weed pressure. In the event of pest occurrence likely to affect yield, appropriate insecticides were applied.

Cultivars were harvested at the same time, when the vast majority of cultivars in the experiment reached physiological maturity, usually in the last decade of July or the first decade of August. Harvesting was performed using plot combine harvesters.

2.3. Weather Conditions During the Experimental Period

Meteorological conditions during the 2023/2024 and 2024/2025 growing seasons varied with respect to both air temperature and total precipitation (

Table 2. Meteorological conditions at the experimental sites during the 2023/2024 growing season.

VTS/VTD/AES	Month									Percentage of Long Term Average
	October	November	December	January	February	March	April	May	June
	Sum of rainfall (mm)
Chrząstowo	55	81	48	33	53	18	36	38	46	120
Dukla	80	94	54	97	60	67	54	30	100	113
Głubczyce	56	90	29	20	43	22	44	48	119	116
Marianowo	93	54	41	33	61	22	35	18	62	117
Pawłowice	73	79	53	48	60	16	60	22	53	113
Radostowo	57	72	31	26	84	35	43	24	61	127
Rarwino	78	66	62	38	55	12	66	40	79	117
Seroczyn	53	49	53	57	51	35	33	11	151	120
Słupia	66	59	37	57	71	33	34	43	91	127
Sulejów	68	46	43	45	37	23	27	74	95	114
Świebodzin	86	47	58	35	72	26	35	41	78	134
Tarnów	42	62	35	20	44	15	16	30	37	81
Uhnin	56	40	53	64	48	44	41	28	87	116
Węgrzce	58	57	37	51	57	34	45	23	94	107
Winna Góra	37	36	57	37	67	24	41	81	81	109
Wrócikowo	76	59	43	46	75	35	43	22	23	108
	average air temperature at a height of 2 m (°C)
Chrząstowo	10.0	3.5	1.7	−0.2	5.2	6.6	10.3	16.8	18.5
Dukla	11.7	4.1	1.0	−0.9	6.5	7.2	11.3	15.3	19.3
Głubczyce	12.6	4.9	2.8	0.0	7.0	7.7	10.5	15.6	18.3
Marianowo	9.7	2.7	1.0	−2.3	4.7	5.5	10.7	17.3	19.4
Pawłowice	12.1	5.0	2.3	0.0	6.9	8.0	11.2	16.9	19.6
Radostowo	9.9	3.3	1.7	−0.5	4.5	5.8	9.3	15.3	17.6
Rarwino	11.2	5.3	3.3	1.8	5.8	7.5	10.0	16.5	17.3
Seroczyn	10.6	3.7	1.5	−0.9	5.8	6.2	11.2	17.5	19.3
Słupia	11.5	4.2	1.7	−0.6	6.1	6.7	11.1	16.3	19.0
Sulejów	11.3	4.2	2.1	−0.3	6.3	7.0	11.0	16.6	19.0
Świebodzin	11.7	5.4	3.3	0.9	6.8	7.8	11.2	16.9	18.7
Tarnów	12.3	5.0	3.2	0.4	6.7	8.3	11.6	16.0	19.3
Uhnin	11.1	3.7	1.3	−1.0	5.8	6.1	11.5	16.5	19.4
Węgrzce	12.1	4.4	2.2	−0.1	6.7	6.6	11.8	16.6	19.5
Winna Góra	11.3	3.9	3.1	0.8	6.9	8.0	11.3	17.1	18.6
Wrócikowo	9.3	2.9	1.3	−1.9	4.5	5.5	9.5	15.5	18.0

and

Table 3. Meteorological conditions at the experimental sites during the 2024/2025 growing season.

VTS/VTD/AES	Month									Percentage of Long Term Average
	October	November	December	January	February	March	April	May	June
	Sum of rainfall (mm)
Chrząstowo	35	18	23	22	12	1	23	57	97	84
Dukla	51	26	21	34	14	32	96	119	58	79
Głubczyce	29	12	9	11	2	32	10	67	59	57
Marianowo	36	21	16	18	9	25	9	78	46	72
Pawłowice	29	25	18	21	2	25	14	47	53	56
Radostowo	35	22	24	46	17	9	28	53	81	92
Rarwino	74	50	25	63	12	2	5	38	48	75
Seroczyn	34	24	31	28	11	30	27	81	47	76
Słupia	34	19	16	32	14	33	28	58	70	78
Sulejów	18	20	8	9	8	30	11	62	49	53
Świebodzin	10	36	15	38	16	13	16	34	63	67
Tarnów	30	20	14	11	3	22	34	79	33	66
Uhnin	43	18	19	24	8	37	19	53	54	68
Węgrzce	39	16	10	18	19	39	17	34	60	59
Winna Góra	35	21	34	27	19	25	30	47	73	65
Wrócikowo	35	27	51	32	14	33	19	80	49	87
	average air temperature at a height of 2 m (°C)
Chrząstowo	9.6	3.7	3.1	1.5	−0.6	6.0	10.7	11.5	17.0
Dukla	10.1	2.5	1.1	1.5	−1.2	6.3	10.2	10.6	18.5
Głubczyce	10.2	3.2	1.6	1.4	−0.1	6.2	10.6	11.1	17.9
Marianowo	9.3	3.5	2.3	1.9	−1.6	6.2	10.7	11.3	17.7
Pawłowice	10.8	3.8	2.1	1.9	0.2	6.5	11.4	11.7	19.0
Radostowo	9.6	4.2	3.6	2.0	−0.5	5.4	9.1	10.5	16.5
Rarwino	11.1	5.6	4.5	2.4	1.2	5.7	10.2	11.6	17.2
Seroczyn	9.5	3.5	2.0	2.3	−1.5	6.6	10.9	11.2	18.0
Słupia	9.7	3.0	1.9	1.3	−0.9	6.4	11.0	11.5	18.5
Sulejów	10.0	3.3	2.6	2.0	−0.6	6.1	11.2	11.6	18.4
Świebodzin	11.1	4.7	3.4	2.5	0.3	6.4	12.0	13.0	19.2
Tarnów	11.1	4.2	2.6	2.6	0.8	6.8	11.4	11.8	18.9
Uhnin	9.4	3.4	1.7	2.3	−1.9	6.8	10.7	11.3	18.4
Węgrzce	10.5	3.4	2.0	2.0	−0.3	7.2	12.2	12.2	20.3
Winna Góra	10.8	4.3	3.3	2.4	−0.1	6.1	11.4	11.4	20.0
Wrócikowo	9.2	3.8	3.0	1.9	−1.5	5.1	9.5	10.0	16.3

).

In the 2023/2024 growing season, the highest precipitation totals were generally recorded in June, which was the wettest month at most sites. In contrast, the lowest precipitation totals most often occurred in February or March, indicating periodic water shortages at the end of winter. In the 2024/2025 growing season, precipitation distribution was more uneven: relatively high totals were recorded in May and June, whereas February was the driest month, with very low precipitation values observed at many experimental sites.

With regard to air temperature, both seasons showed a similar overall pattern, although some differences were evident. In the 2023/2024 growing season, higher temperatures were observed in the spring months (especially April and May), which may have accelerated plant development. In contrast, the 2024/2025 growing season was characterized by lower winter temperatures (particularly in February), along with locally slightly higher values in June.

In the 2023/2024 growing season, sites with higher precipitation totals relative to the long-term average were clearly distinguished, such as Świebodzin, Radostowo, and Słupia (127–134% of the long-term mean). This indicates locally more humid conditions, which may have favored plant growth but could also potentially increase the risk of plant diseases. In contrast, Tarnów was characterized by a markedly lower share of precipitation relative to the long-term average (approximately 81%), indicating relatively drier conditions at this site.

In the 2024/2025 growing season, spatial variability among locations was even more pronounced. The most humid conditions were recorded, among others, in Wrócikowo and Radostowo (approximately 87–92% of the long-term average), whereas particularly dry conditions occurred in Głubczyce, Sulejów, and Węgrzce (approximately 53–59%). This indicates that, at some locations, precipitation deficits may have been much more severe than the average for the entire experiment.

With respect to air temperature, differences among experimental sites were smaller than those observed for precipitation. Nevertheless, it can be noted that sites located in warmer regions (e.g., Pawłowice, Tarnów) were characterized by slightly higher temperatures during the spring–summer period, whereas northern and western locations (e.g., Chrząstowo, Świebodzin) exhibited a somewhat cooler temperature regime.

A comparison of the two growing seasons indicates that precipitation was the main factor differentiating the growing conditions for winter triticale. The 2023/2024 growing season was characterized by more evenly distributed and generally higher moisture conditions, with maximum precipitation occurring in June. In contrast, the 2024/2025 growing season was clearly drier, with precipitation deficits particularly evident in February and partly during the spring period. Differences in temperature were less pronounced. Consequently, the 2023/2024 growing season can be considered more favorable for yield formation, whereas the 2024/2025 growing season was associated with a higher risk of water stress.

2.4. Statistical Analysis

The normality of distribution of the traits was tested using the Shapiro–Wilk’s normality test [28]. Homogeneity of variances was evaluated using Bartlett’s test. Four-way analyses of variance (ANOVA) were carried out to determine the effects of management intensity, cultivar, growing season, environment as well as all interactions on the variability of yield, powdery mildew, brown rust and septoria leaf blotch. The minimal and maximal values, arithmetic means and standard deviations of traits were calculated. The distribution of observed traits was graphically presented in density plots. Fisher’s least significant differences (LSDs) were estimated at a significance level of α = 0.05. Homogeneous groups for the analyzed traits were determined based on LSDs. The relationships between the observed traits were estimated using Pearson correlation coefficients and presented graphically as a heatmap. A canonical variate analysis was applied in order to present a multi-trait assessment of the similarity of the tested experimental treatments in a lower number of dimensions with the least possible loss of information [29]. This facilitated graphic presentation of any variation in the experimental treatments in terms of all the observed traits. The Mahalanobis distance was suggested as a measure of similarity for “polytrait” experimental treatments [30], the significance of which was verified by means of critical value Dα called “the least significant distance” [31]. Mahalanobis distances were calculated for all pairs of experimental treatments. All analyses were conducted using the Genstat 24.2 statistical software package [32].

3. Results

The empirical distribution of all observed characteristics followed a normal distribution. The results of the Bartlett test indicated homogeneity of variance. These results justify the use of analysis of variance. Analysis of variance indicated that the main effects of management intensity, cultivar, growing season, environment as well as interactions: management intensity × environment, cultivar × environment, growing season × environment, management intensity × growing season × environment and cultivar × growing season × environment were significant for all four traits of the study (

Table 4. Mean squares from four-way analysis of variance for individual traits.

Source of Variation	d.f.	Yield	Powdery Mildew	Brown Rust	Septoria Leaf Blotch
Management intensity	1	11.63 ***	38.1276 ***	10.0104 ***	46.0651 ***
Cultivar	2	10.94 ***	3.2839 ***	2.9401 ***	3.1484 ***
Growing Season	1	23.21 ***	15.4401 ***	3.7604 ***	1.6276 **
Environment	15	68.73 ***	6.804 ***	10.4833 ***	10.9179 ***
Management intensity × Cultivar	2	0.49 ns	2.7526 ***	0.7214 **	0.7057 *
Management intensity × Growing Season	1	0.08 ns	0.9401 *	0.1667 ns	1.1484 *
Cultivar × Growing Season	2	0.12 ns	0.0182 ns	0.5807 *	0.1589 ns
Management intensity × Environment	15	0.94 ***	1.4887 ***	0.7271 ***	1.6707 ***
Cultivar × Environment	30	2.37 ***	0.6977 ***	0.6151 ***	0.9595 ***
Growing Season × Environment	15	25.12 ***	9.979 ***	12.5438 ***	13.8998 ***
Management intensity × Cultivar × Growing Season	2	0.68 ns	0.237 ns	0.362 ns	0.7578 *
Management intensity × Cultivar × Environment	30	0.27 ns	0.472 ***	0.263 **	0.428 ***
Management intensity × Growing Season × Environment	15	1.21 ***	1.679 ***	0.5389 ***	2.3762 ***
Cultivar × Growing Season × Environment	30	1.81 ***	0.3655 ***	0.8724 ***	0.8311 ***
Management intensity × Cultivar × Growing Season × Environment	30	0.33 ns	0.4342 ***	0.2092 *	0.2856 ns
Residual	192	0.35	0.1641	0.1302	0.2005

* p < 0.05; ** p < 0.01; *** p < 0.001; ns—not-significant.

and

Table 5. Mean values of all main effects and least significant differences (LSD_0.05).

Factor	Yield (t/ha)	Powdery Mildew	Brown Rust	Septoria Leaf Blotch
Management intensity
a1	8.94	8.031	8.38	7.646
a2	10.04	8.661	8.703	8.339
LSD0.05	0.1195	0.0815	0.0726	0.0901
Cultivar
Fanfaro	9.16	8.344	8.367	7.812
Medalion	9.57	8.508	8.641	8.063
SU Atletus	9.73	8.187	8.617	8.102
LSD0.05	0.1463	0.0999	0.089	0.1104
Growing Season
2024	8.71	8.146	8.641	8.057
2025	10.27	8.547	8.443	7.927
LSD0.05	0.1195	0.0815	0.0726	0.0901
Environment
Chrząstowo	11.53	8.333	8.292	7.5
Dukla	6.34	9	8.417	7.75
Głubczyce	11.56	8.458	8.708	7
Marianowo	10.50	8.125	9	7.792
Pawłowice	9.87	7.833	9	8
Radostowo	12.11	8.458	8.458	7.958
Rarwino	9.62	6.958	6.417	6.333
Seroczyn	9.74	8.458	9	8.833
Sulejów	8.06	8.667	8.75	8.5
Słupia	8.42	8.667	8.625	7.958
Tarnów	10.31	7.542	9	8.708
Uhnin	7.41	9	9	8.458
Winna Góra	8.11	8.25	8.208	7.833
Wrócikowo	11.38	8.417	9	8.542
Węgrzce	7.88	8.583	7.917	7.875
Świebodzin	9.01	8.792	8.875	8.833
LSD0.05	0.3379	0.2306	0.2055	0.255

). Management intensity × cultivar as well as management intensity × cultivar × environment interactions were significant for powdery mildew, brown rust and septoria leaf blotch (Table 4). Management intensity × growing season interaction was significant for powdery mildew and septoria leaf blotch. Management intensity × cultivar × growing season × environment interaction was significant for powdery mildew and brown rust. The cultivar × growing season interaction was significant only for brown rust and management intensity × cultivar × growing season interaction for septoria leaf blotch (Table 4).

3.1. Infection of Winter Triticale Cultivars by Powdery Mildew (B. graminis)

During the years of the study, winter triticale cultivars showed varied levels of infection by powdery mildew depending on the location and the intensity level of crop protection (Figure 2, Figure 3, Figure 4 and Figure 5, Table 5).

In the 2023/2024 growing season, cultivar Fanfaro at the a1 level showed no visible powdery mildew symptoms at five locations (Dukla, Głubczyce, Sulejów, Uhnin, and Węgrzce). In the first year of the study, the highest infection of Fanfaro at the a1 level was recorded at Rarwino, Pawłowice, and Tarnów, with disease severity ranging from 5.0° to 6.0° on the 9.0-point scale (Figure 2, Table 5).

At the a2 level in the 2023/2024 growing season, under more intensive crop protection and fertilization, the cultivar Fanfaro received the maximum disease score (9.0°) at 12 locations. At the Rarwino site, however, Fanfaro received a disease score of 4.0°, indicating substantial disease severity (Figure 3, Table 5).

The second cultivar examined, Medalion, at the a1 level in the 2023/2024 growing season, was characterized by relatively good resistance. At seven locations, no visible powdery mildew symptoms were recorded. At Rarwino, Pawłowice, and Tarnów, plants were more severely affected, with values ranging from 5.0° to 6.0° on the 9-point scale. At the a2 level, again at the Rarwino location, the cultivar was strongly infected by B. graminis, while at the remaining locations the cultivar showed good resistance (Figure 2 and Figure 3).

The cultivar SU Atletus, in the 2023/2024 growing season at the a1 level, was more heavily infected at Głubczyce, Pawłowice, Rarwino, and Tarnów, with disease severity ranging from 4.0° to 5.5°. At the a2 level, increased infection was recorded at Rarwino (5.5°) (Figure 2 and Figure 3).

In the second growing season (2024/2025), cultivar Fanfaro at the a1 level showed disease scores ranging from 7.0° (Chrząstowo) to 9.0° at eight locations (Dukla, Pawłowice, Rarwino, Uhnin, Winna Góra, Wrócikowo, Węgrzce, and Świebodzin) (Figure 4, Table 5).

At the a2 level, the cultivar was also characterized by good resistance, with values ranging from 8.0° (Chrząstowo, Marianowo) to 9.0° at several locations (Dukla, Głubczyce, Pawłowice, Radostowo, Rarwino, Słupia, Uhnin, Węgrzce, and Świebodzin) (Figure 5, Table 5).

Cultivar Medalion, at the a1 level in the 2024/2025 growing season, showed low powdery mildew severity. At nine locations, no powdery mildew infection was recorded. At the Węgrzce site, Medalion received a score of 6.5° on the 9-point scale. At the a2 level, in the vast majority of locations (14), the cultivar scored 9.0°, indicating the absence of visible disease symptoms. At the Tarnów and Wrócikowo sites, Medalion was only slightly affected, with a disease severity score of 8.5° (Figure 4 and Figure 5, Table 5).

In the 2024/2025 season, cultivar SU Atletus at the a1 level was most severely infected at the Wrócikowo site (5.5°). At Dukla, Pawłowice, Rarwino, Uhnin, Winna Góra, and Świebodzin, SU Atletus showed no visible disease symptoms (9.0°). At the a2 level, the lowest resistance score recorded was 8.0° at Tarnów (Figure 4 and Figure 5).

3.2. Infection of Winter Triticale Cultivars by Brown Rust (P. recondita)

With regard to another disease—brown rust (P. recondita)—winter triticale cultivars also showed varied levels of infection depending on location and the intensity of crop protection (Figure 6, Figure 7, Figure 8 and Figure 9, Table 5).

In the 2023/2024 season, cultivar Fanfaro at the a1 level showed complete resistance at nine locations (Chrząstowo, Marianowo, Pawłowice, Rarwino, Seroczyn, Sulejów, Tarnów, Uhnin, and Wrócikowo). In the first year of the study, the highest infection of Fanfaro at the a1 level was recorded at Dukla (4.5°) and Głubczyce (6.0°) on the 9.0-point scale (Figure 6, Table 5).

At the a2 level in the 2023/2024 season, under more intensive protection and fertilization, Fanfaro received the maximum disease score (9.0°) at thirteen locations. At the Dukla and Węgrzce sites, however, the cultivar was more strongly affected by brown rust, with a disease severity score of 7.0° (Figure 7, Table 5).

The second cultivar examined, Medalion, at the a1 level in the 2023/2024 growing season was characterized by low brown rust severity. At eleven locations, no visible brown rust symptoms were recorded (9.0°). Higher disease severity was noted at Winna Góra (7.5°). At the a2 level, again at the Winna Góra site, the cultivar was more severely affected by brown rust (7.5°), while high disease scores were recorded at the remaining locations (Figure 6 and Figure 7).

In the 2023/2024 season, cultivar SU Atletus at the a1 level was more strongly affected at the Słupia and Winna Góra sites (7.5°). At the a2 level, increased infection was again recorded at Winna Góra (7.0°) (Figure 6 and Figure 7, Table 5).

In the second growing season (2024/2025), cultivar Fanfaro at the a1 level showed highly variable responses to Puccinia recondita. Disease severity ranged from 3.0° at the Rarwino site to 9.0° at nine locations (Dukla, Marianowo, Pawłowice, Seroczyn, Tarnów, Uhnin, Winna Góra, Wrócikowo, and Świebodzin) (Figure 8, Table 5).

At the a2 level, with the exception of Rarwino (4.0°), the cultivar showed full resistance, with values ranging from 8.0° (Węgrzce) to 9.0° at the remaining locations (Figure 9, Table 5).

Cultivar Medalion at the a1 level in the 2024/2025 growing season also exhibited variable disease responses. At the Rarwino site, similarly to cultivar Fanfaro, very high disease severity was observed (3.5° on the 9-point scale). At the other locations, disease severity ranged from 7.0° (Węgrzce) to 9.0° at ten locations. At the a2 level, in the vast majority of locations (14), the cultivar received a score of 9.0°, indicating the absence of visible disease symptoms. At Rarwino, however, Medalion was severely affected, with a score of 4.0° (Figure 8 and Figure 9).

In the 2024/2025 season, cultivar SU Atletus at the a1 level was most severely affected at the Rarwino site (3.5°). At eleven locations, the cultivar received the maximum disease score (9.0°). At the a2 level, except for Rarwino (4.5° on the 9-point scale), SU Atletus received the maximum disease score (9.0°) (Figure 8 and Figure 9, Table 5).

3.3. Infection of Winter Triticale Cultivars by Septoria Leaf Blotch (Z. tritici)

Winter triticale cultivars, depending on the location and the level of intensity of crop protection, showed varying degrees of infection by septoria leaf blotch (Figure 10, Figure 11, Figure 12 and Figure 13, Table 5).

The cultivar Fanfaro, in the 2023/2024 growing season at the a1 level, showed no visible disease symptoms in only three locations (Rarwino, Tarnów, and Uhnin). High disease severity was recorded in Marianowo (5.0°) and Głubczyce (5.5°) on a 9.0-point scale (Figure 10, Table 5).

At the a2 level, in the 2023/2024 season, under more intensive crop protection and fertilization, Fanfaro received a disease score of 9.0° in eight locations (Głubczyce, Pawłowice, Rarwino, Seroczyn, Słupia, Tarnów, Wrócikowo, and Świebodzin). Higher disease severity was observed in Dukla (7.0°) (Figure 11, Table 5).

The cultivar Medalion, at the a1 level in the 2023/2024 season, was characterized by variable resistance. In three locations, no disease infection was recorded. High disease severity was observed in Głubczyce and Pawłowice (6.0° on the 9.0-point scale). At the a2 level, disease severity ranged from 8.0° to 9.0° (Figure 10 and Figure 11).

The cultivar SU Atletus, in the 2023/2024 season at the a1 level, was most severely infected in Głubczyce (6.5°). In four locations—Dukla, Rarwino, Tarnów, and Wrócikowo—SU Atletus showed no visible disease symptoms (9°). At the a2 level, the lowest disease severity recorded was 7.0° (Uhnin) (Figure 10 and Figure 11, Table 5).

In the 2024/2025 season, at the a1 level, the cultivar Fanfaro showed no visible disease symptoms (9°) in five locations (Pawłowice, Sulejów, Tarnów, Węgrzce, and Świebodzin). Very severe infection of Fanfaro was recorded in Rarwino (3.0°) (Figure 12, Table 5).

At the a2 level, the cultivars were also characterized by resistance, ranging from 3.5° (Rarwino) to 9.0° (Marianowo, Pawłowice, Radostowo, Sulejów, Tarnów, Uhnin, Wrócikowo, and Świebodzin) (Figure 13, Table 5).

In the second year of the study, the Medalion cultivar at the a1 level showed resistance ranging from 2.5° (Rarwino) to 9.0° (Dukla, Pawłowice, Seroczyn, and Świebodzin). At the a2 level, the cultivar achieved a score of 9.0° (no infection) in nine locations. In Rarwino, infection was very severe (4.0°) (Figure 12 and Figure 13, Table 5).

The SU Atletus cultivar, in the 2024/2025 season at the a1 level, was most severely infected in Rarwino (4.0°) and Głubczyce (6.5°). In Pawłowice, Seroczyn, Tarnów, Winna Góra, and Świebodzin, SU Atletus showed no visible disease symptoms (9°). At the a2 level, disease severity ranged from 5.0° (Rarwino) to 9.0° (nine locations) (Figure 12 and Figure 13, Table 5).

3.4. Winter Triticale Cultivars Yielding

At the a1 level in the first year of the study (2023/2024) the cultivar Medalion was characterized by the most stable yield performance, showing relatively small yield fluctuations among locations. At most sites, its yield ranged from approximately 8.50 to 10.50 t/ha (Pawłowice—8.56 t/ha–8.70 t/ha; Świebodzin—8.95 t/ha–9.20 t/ha; Radostowo—10.58 t/ha–10.69 t/ha; and Chrząstowo—9.84 t/ha–10.11 t/ha).

In contrast, cultivar Fanfaro exhibited much greater yield variability, ranging from very low values at Słupia (3.16 t/ha–3.51 t/ha) to high yields at locations with more favorable conditions, such as Radostowo (10.93 t/ha–11.09 t/ha) and Wrócikowo (10.25 t/ha–10.39 t/ha). Wider yield amplitude was observed for SU Atletus, whose yield ranged from 3.95 t/ha at Uhnin to 12.25 t/ha at Radostowo. At several high-potential locations (e.g., Głubczyce—11.38 t/ha–11.75 t/ha; Chrząstowo—10.56 t/ha–10.82 t/ha), this cultivar achieved very high yields; however, its performance was strongly dependent on environmental conditions.

These results indicate that Medalion has the most relatively consistent yield under lower agrotechnical intensity, whereas Fanfaro and SU Atletus are more sensitive to site-related variability (Figure 14).

At the a2 level, in the 2023/2024 season, a clear increase in yield levels was observed across all locations and cultivars (Table 5). Yields of the cultivar Medalion remained relatively uniform, most often ranging from 9.00 t/ha to 11.50 t/ha (e.g., Pawłowice–9.25 t/ha–9.54 t/ha; Świebodzin–9.50 t/ha–9.63 t/ha; Chrząstowo—11.19 t/ha–11.31 t/ha), confirming relatively high yield consistency of this cultivar also under a higher level of agrotechnical intensity.

Cultivar Fanfaro continued to show considerable yield variability (Table 5), although at a distinctly higher yield level—from 3.93 t/ha–4.67 t/ha at Słupia to as much as 12.46 t/ha at Wrócikowo and 11.75 t/ha–11.84 t/ha at Radostowo. The highest yields were obtained by cultivar SU Atletus, reaching up to 12.89 t/ha at Radostowo and 12.70 t/ha at Chrząstowo, while maintaining high yield levels at other locations as well (e.g., Głubczyce—12.05 t/ha–12.36 t/ha). Nevertheless, substantial variability was still observed, particularly at less favorable sites (e.g., Uhnin—6.32 t/ha–6.41 t/ha).

At the a2 level, yield increased on average by several to more than a dozen t/ha, depending on the location (e.g., in Głubczyce, the yield of Fanfaro increased by approximately 2.50 t/ha–3.00 t/ha), with the greatest effects observed in environments with high production potential (Figure 15).

In the 2024/2025 season, under the a1 level, a pronounced differentiation in yield among locations was recorded. The range of yields was wide—from 5.19 t/ha–5.77 t/ha in Dukla to over 12.00 t/ha–13.20 t/ha in Słupia (SU Atletus–12.84 t/ha–13.24 t/ha) and Radostowo (Medalion–12.35 t/ha–12.84 t/ha).

The cultivar Medalion also showed greater variability than in the previous season, with yields ranging from 5.19 t/ha–5.72 t/ha in Dukla to 12.35 t/ha–12.84 t/ha in Radostowo, and from approximately 11.00 t/ha to 11.60 t/ha in Chrząstowo and Wrócikowo. Cultivar Fanfaro was characterized by high yield variability, ranging from 5.64 t/ha–5.78 t/ha in Dukla and 6.70 t/ha–8.30 t/ha in Seroczyn to 11.39 t/ha–12.39 t/ha in Chrząstowo, as well as exceeding 11.00 t/ha in Tarnów and Radostowo.

Once again, the highest yields were achieved by cultivar SU Atletus; however, these were accompanied by considerable variability—from 6.80 t/ha–7.38 t/ha in Uhnin and Węgrzce, and 6.88 t/ha–6.94 t/ha in Świebodzin, to 12.84 t/ha–13.24 t/ha in Słupia and 12.22 t/ha–12.34 t/ha in Tarnów. The obtained results confirm that under a lower level of agrotechnical intensity (a1), the influence of environmental conditions was very strong, leading to large differences among locations and increased yield variability for all cultivars (Figure 16).

In the 2024/2025 season, the application of the a2 agrotechnical level clearly increased yield levels at all locations and reduced yield variability. In many cases, yields exceeded 12.00 t/ha with maximum values reaching up to 14.79 t/ha (SU Atletus at the Słupia). The cultivar Medalion maintained relatively high consistent yield, most often achieving 11.00 t/ha–13.00 t/ha (e.g., Słupia–12.76 t/ha–13.02 t/ha; Radostowo–13.71 t/ha–14.21 t/ha; Głubczyce–12.52 t/ha–12.69 t/ha).

Cultivar Fanfaro also showed a marked increase in yield—from 7.58 t/ha–8.18 t/ha at Dukla and approximately 7.70 t/ha–7.90 t/ha at the Uhnin and Węgrzce sites to over 13.00 t/ha at Chrząstowo (13.04 t/ha–13.14 t/ha) and 13.34 t/ha–13.36 t/ha at Radostowo. Once again, the highest yields were obtained by cultivar SU Atletus, which achieved very high values under favorable conditions—14.10 t/ha–14.79 t/ha at Słupia, 13.25 t/ha at Chrząstowo, 13.90 t/ha–14.00 t/ha at Głubczyce, and 13.40 t/ha–13.61 t/ha at Radostowo. Even at less favorable locations, yields of this cultivar remained relatively high (e.g., Dukla—8.21 t/ha–8.28 t/ha) (Figure 17).

Individual traits had varying importance and contributed differently to the total multivariate variability across the studied combinations of differentiating factor levels. The analysis of the first two canonical variates for the 192 combinations across the four quantitative traits is presented in Figure 18. The first two canonical variates accounted for 74.42% of the total variability between the individual combinations (Figure 18). The most significant positive linear relationship with the first canonical variate was found for yield (0.969), while a significant negative relationship was found for brown rust (−0.146) and septoria leaf blotch (−0.229). The second canonical variate was significantly positively correlated with brown rust (0.933), septoria leaf blotch (0.855), and yield (0.224).

The distribution of treatment combinations in the canonical variate space allowed identification of agronomically contrasting groups. Combinations located in the region of high V₁ and low V₂ values were characterized by a favorable combination of high grain yield and low disease incidence. This group included mainly the 2024/2025 season combinations from the Rarwino location, particularly Medalion and SU Atletus under both management levels (a1 and a2), as well as Fanfaro, indicating superior overall performance across the four analyzed traits. In contrast, combinations positioned on the negative side of V1, especially Fanfaro, Medalion and SU Atletus at location SW in the 2023/2024 season, represented the least favorable multivariate profiles, associated with lower overall performance. The highest values of the first canonical variate were observed mainly for SU Atletus under the intensive management level (a2), confirming the high yield potential of the cultivar under favorable production conditions. However, some of these combinations were simultaneously associated with relatively high V₂ values, indicating increased contributions of brown rust and septoria leaf blotch to their multivariate profiles. Therefore, although SU Atletus expressed the greatest production potential, Medalion showed a more balanced combination of yield and disease resistance. Overall, the canonical variate analysis demonstrated that intensive management (a2), particularly in the 2024/2025 season, generally shifted treatment combinations toward the region representing superior agronomic performance.

The greatest yield variability was observed in Słupia, whereas the lowest variability was recorded in Sulejów (Figure 19).

Yield variability among individual locations was characterized by a very similar range of variation (Figure 20).

A higher yield was recorded in the second year of observations (2025); however, yield variability in both years was similar (Figure 21).

A statistically significant positive correlation (at the 0.001 significance level) was observed between brown rust and septoria leaf blotch (r = 0.668) (Figure 22). No correlations were found for the remaining trait pairs (Figure 22).

4. Discussion

Protecting crop fields against plant pathogens is one of the most important components of cereal production [19,20]. As the use of plant protection products and mineral fertilizers is becoming increasingly restricted, the cultivation of varieties with natural resistance to plant diseases and enhanced tolerance to abiotic stress factors represents one of the most effective and sustainable solutions. Owing to the research conducted within the PRVT system, agricultural practice has direct access to the results of scientific experiments, including information on the susceptibility of individual varieties to the most important diseases. The results obtained from these studies indicate the suitability of specific varieties for particular regions of Poland. The selection of resistant varieties that simultaneously show the highest level of resistance under local conditions is a fundamental decision made before establishing a plantation and determines the achievement of satisfactory income. In addition to their practical value, the experimental results also constitute a rich scientific database on the basis of which numerous further statistical analyses can be carried out [31,32].

The significant positive correlation between brown rust and septoria leaf blotch may be associated with environmental conditions favorable for the development of both diseases, particularly high humidity and prolonged leaf wetness. Similar environmental factors have been identified as important drivers of foliar disease development in cereals [15]. In addition, cultivars susceptible to one foliar pathogen may also exhibit increased susceptibility to other diseases. However, because the present study was conducted under natural infection conditions across multiple locations and growing seasons, the observed correlation should not be interpreted as evidence of a direct causal relationship between the two diseases.

Overall, a higher yield level was obtained in the 2024/2025 growing season compared with 2023/2024. At the a1 level, this increase was particularly pronounced—for example, in Słupia. Yields of SU Atletus increased from approximately 4.10 t/ha–5.40 t/ha (2023/2024) to 12.80 t/ha–13.20 t/ha (2024/2025). In Radostowo, yields of Medalion increased from about 10.60 t/ha to 12.30 t/ha–12.80 t/ha.

At the same time, greater variability in results at the a1 management intensity was observed in 2024/2025, especially at less favorable locations (e.g., Dukla and Uhnin), indicating a stronger influence of environmental conditions. At the a2 management intensity, both growing seasons were characterized by high and more uniform yields; however, the 2024/2025 growing season also produced higher maximum values. The highest yields of SU Atletus increased from approximately 12.60 t/ha–12.90 t/ha (2023/2024) to 14.10 t/ha–14.80 t/ha (2024/2025).

At high-yielding locations (e.g., Radostowo, Głubczyce), yield increases most often ranged from 1.00 t/ha to 2.00 t/ha, whereas at less favorable sites (e.g., Dukla), intensification still resulted in clear benefits, raising yields from approximately 6.00 t/ha–7.00 t/ha to 7.00 t/ha–8.00 t/ha. In both growing seasons, cultivar Medalion demonstrated relatively high and consistent yield, whereas SU Atletus achieved the highest yields under favorable conditions but exhibited greater variability. Cultivar Fanfaro occupied an intermediate position, responding clearly to improvements in cultivation conditions [32,33].

The Medalion variety showed relatively consistent yield across locations, while the SU Atletus variety achieved the highest yields under favorable conditions but with greater variability. The Fanfaro variety also showed significant variability in grain yield and disease response across environments, reflecting significant cultivar × environment interactions. Increasing the intensity of management practices (a2) resulted in a 12.4% increase in average grain yield (from 8.88 to 9.98 t/ha) compared to the a1 management intensity, and improved disease resistance scores by 10.3% for powdery mildew, 6.3% for brown rust, and 9.3% for leaf spot. These results indicate a beneficial effect of more intensive cultivation technology on both yield levels and reduced disease pressure in winter triticale.

The relatively consistent yield of the Medalion cultivar across locations is consistent with previous studies conducted within the Polish PRVT system, which demonstrated that cultivar responses are strongly influenced by environmental conditions and management intensity, although some cultivars maintain greater yield stability across environments [22,25,34]. In turn, the greater yield variability observed for the Fanfaro and SU Atletus cultivars confirms the importance of genotype × environment interactions in winter triticale cultivation.

The higher yields recorded in the 2024/2025 season may have been related to drier weather conditions during this growing season. Lower rainfall and shorter leaf wetness likely limited the development of leaf spot and other leaf diseases, thereby reducing yield losses. Consequently, despite lower rainfall, reduced disease pressure may have contributed to better plant development and higher grain yields.

The main objective of PRVT is to provide agricultural producers with reliable and objective information on the economic value of crop cultivars listed in the NR and the Common Catalogue of Varieties (CCV) [18]. These studies are practical in nature—their purpose is to support farmers in selecting cultivars best adapted to local environmental and technological conditions [25]. As a result, it is possible to make more effective use of the yield-forming potential of crops and to better adjust plant production to changing farming conditions.

The PRVT system is based on an extensive network of field trials conducted in various regions of the country. These experiments are implemented by numerous entities, including experimental stations, agricultural advisory centers, scientific institutions, and breeding and seed companies [18,19].

One of the most important outcomes of the PRVT system is the development of the “ List of varieties recommended for cultivation within the territory of the Voivodeship” The recommended cultivars are usually characterized by stable yield performance; however, in some cases, specialized genotypes that adapt well to specific environmental conditions are also preferred [34].

Research conducted within the PRVT framework also has a cognitive value, as it enables the analysis of genotype × environment interactions. It has been demonstrated that yield level and yield stability are significantly influenced by climatic factors, soil properties, and the level of agrotechnical management [33,34].

The PRVT system provides practical information supporting cultivar selection under diverse environmental and agronomic conditions. However, in the context of this study, its role is primarily methodological, as it enables the evaluation of cultivar performance across multi-location field trials and supports the interpretation of genotype × environment interactions. The results of this study demonstrate clear differences in winter triticale performance depending on cultivar, management intensity, and environmental conditions. Cultivar Medalion showed the most stable performance across locations and seasons, while SU Atletus expressed the highest yield potential under favorable conditions but greater environmental sensitivity. Fanfaro exhibited intermediate performance in both yield and disease response. Increasing management intensity (a2) significantly improved grain yield and reduced disease severity across cultivars, although the magnitude of these effects depended strongly on the location and growing season. The significant interactions observed in the ANOVA confirm that cultivar performance and disease development are highly environment-dependent, highlighting the importance of adapting cultivar choice to local conditions. A limitation of this study is the lack of continuous monitoring of disease development stages and the absence of modelling linking disease severity with detailed meteorological variables. Future research should integrate phenology-based disease assessments with high-resolution weather data to better understand epidemic dynamics and improve cultivar recommendation systems.

5. Conclusions

• It was confirmed that management intensity has a significant effect on both grain yield and the health status of winter triticale.
• Management intensity (a2) resulted in higher grain yield and reduced disease severity across all tested cultivars.
• Significant differences among cultivars were observed in both yield level and stability; ‘Medalion’ showed the most stable performance, whereas ‘SU Atletus’ expressed the highest yield potential under favorable conditions.
• Environmental conditions, including growing season and location, had a significant effect on both yield and disease development.
• The observed genotype × environment interactions indicate that cultivar performance is strongly dependent on local environmental conditions.