In this study, we aimed to examine the multiplicative interaction model as a tool to assess the impact of plant extracts and fermentation products on the growth of mycelium of selected fungi. The materials used in the study included a total of 16 products. Plant extracts were obtained by the processes of ultrasound-assisted extraction (UAE) or supercritical CO2 extraction, and the fermentation broths were produced by Enterobacter and Paenibacillus bacteria in a bioreactor. All these products were examined in vitro using 12 cultures of frequently occuring pathogenic fungi collected from cereals and oilseed rape cultivation. For mycelium diameter in all three examined concentrations, the Additive Main impacts and Multiplicative Interaction (AMMI) analyses showed substantial impacts of both the product and the pathogen as well as the product-by-pathogen interaction. It is advised that future plant protection techniques incorporate product E8, a plant extract (the CO2 extract of a ginger plant belonging to the Zingiberaceae family), since it demonstrated excellent stability and good average mycelium diameter values across all concentrations examined. As far as the authors are aware, this is the first time the AMMI model has been used to evaluate the impact of product–pathogen interactions on mycelium diameter.

Terpenoid S, Cu lignosulfonate, Cu heptagluconate (single and in mixts.), and substances contg. Bacillus velezensis and B. amyloliquefaciens were used to control Fusarium blight of wheat seedlings and compared with the synthetic fungicide tebuconazole. In vitro tests, Cu heptagluconate and its mixt. with terpenoid S completelyinhibited mycelial growth of F. culmorum and F. avenaceum, similarly to tebuconazole. Cu lignosulfonate demonstrated high efficacy, while terpenoid S alone slightly limited mycelial growth. In the blotter test, tebuconazole showed the highest efficacy in reducing seedling blight, followed by Cu lignosulfonate. Cu lignosulfonate also positively affected biometric parameters of seedlings, demonstrating dual fungicidal and biostimulating effects.

Plant extracts and microbiological supernatants were subjected to qualitative and compositional analyses to characterize their bioactive profiles and assess their potential agricultural applications. The garlic (Allium sativum) extract was rich in allicin and selected free amino acids, contained betulin as the dominant triterpene, and displayed a favorable elemental profile with high levels of potassium, phosphorus, sulfur, calcium, and magnesium, with no detectable heavy metals. Detectable amounts of B-group vitamins and vitamin E isoforms were also identified. Qualitative phytochemical screening confirmed the presence of saponins and flavonoids in the garlic extract. The Jerusalem artichoke (Helianthus tuberosus) extract exhibited a significantly higher total phenolic content compared to the garlic extract, with qualitative analysis confirming the presence of saponins, tannins, and flavonoids, suggesting a broader spectrum of bioactive compounds. The two bacterial supernatants were characterized by HPLC analysis and differed in their metabolic profiles: the Enterobacter sp. fermentation broth contained glycerol, 2,3-butanediol, and acetic acid, while the Paenibacillus sp. supernatant additionally contained lactic acid, ethanol, and succinic acid, reflecting distinct fermentation pathways. The in vitro and greenhouse studies aimed to evaluate biological preparations for controlling wheat diseases caused by fungi of the Fusarium genus as well as diseases affecting the stem base. Plant extracts (garlic-Allium sativum, Jerusalem artichoke-Helianthus tuberosus) and supernatants (fermentation broths) obtained with the Paenibacillus and Enterobacter bacteria were tested at three concentrations. In laboratory experiments, the degree of inhibition of the growth of the mycelium of the tested fungal species was determined, while in greenhouse studies, the effectiveness in limiting the development of stem base diseases and the impact of the applied biopreparations on plant growth were evaluated. Among the plant extracts, H. tuberosus demonstrated superior antifungal activity, achieving up to 100% inhibition of R. cerealis mycelial growth at 10% concentration and reducing disease severity by 34.3% compared to the untreated control under greenhouse conditions. Paenibacillus sp. supernatant demonstrated strong in vitro antifungal activity. The results indicate that H. tuberosus extract represents a promising candidate for further field evaluation as a component of sustainable wheat protection programs.

The political conclusion of the EU–Mercosur Partnership Agreement in December 2024marks a significant shift in global agri-food trade and raises fundamental questions onregulatory coherence in plant protection. This study provides a comprehensive comparativeassessment of crop protection systems in soybean (Glycine max L.) production betweenthe European Union (represented by Poland) and Mercosur countries. Soybean wasselected due to its strategic importance in global feed supply chains, the EU’s structuralimport dependence, and the crop’s high reliance on chemical and biological plant protectionproducts (PPPs). The analysis reveals pronounced asymmetries in the availability ofauthorizedactive substances. Mercosur producers have access to 96 herbicide active substancescompared to 16 in Poland (ratio 6 : 1); 96 chemical fungicide active substancescompared to 5 (19 : 1); and 94 chemical insecticide active substances compared to only 2(47 : 1). The disparity is particularly striking for biological fungicides, where 104 microbialstrains are registered in Mercosur versus 2 in Poland (52 : 1). Even in biological insecticides,the ratio remains 3 : 1 (9 vs. 3). Approximately 100 active substances used in Mercosursoybean production are not approved in the EU. Pesticide application intensity in Brazil(12.63 kg a.s./ha) is 4.7 times higher than the EU average and over seven times higherthan in Poland. In parallel, Maximum Residue Limits (MRLs) for selected substances differsubstantially, in extreme cases by up to 200-fold. These quantitative asymmetries translateinto divergent pest management capacity, resistance management flexibility, and productionresilience. While the EU regulatory framework reflects a precautionary approach withprogressive restriction of active substances, Mercosur systems operate with substantiallybroader chemical and biological portfolios enabling diversified and rotation-based controlstrategies. The findings demonstrate that regulatory differences – ranging from 6 : 1 to52 : 1 depending on product category – constitute a structural factor shaping competitiveness,resistance risk, and food safety governance under the evolving EU–Mercosur tradeframework.

The possibility of using synthetic fungicides from the triazole and strobilurin groups together with biol. plant protection products was tested. Their effect on inhibiting the growth of mycelium of fungi of the genus Fusarium was detd. All fungicide variants contg. tebuconazole completely inhibited the growth of mycelium of the tested pathogens. The addn. of selected biofungicides to azoxystrobin contributed to an increase in the effect of action compared to the substance from the strobilurin group alone. In the case of prothioconazole, all fungicide variants showed similar efficacy.

The effect of synthetic and biol. preparations on inhibiting the growth of mycelium of the economically important fungi of the Fusarium genus was studied. Products contg. Cu hydroxide, Cu heptagluconate, and Bacillus bacteria: B. velezensis, B. subtilis, and B. amyloliquefaciens were used. A synthetic fungicide contg. the active ingredient prothioconazole was used for comparison. The studies were conducted in vitro on PDA (potato glucose agar) medium. The Cu compounds and Bacillus bacteria used inhibited the growth of Fusarium fungi. This effect depended on the product type and the fungus species tested.

This study investigates the biocontrol potential of Trichoderma asperellum and Coniothyrium minitans against the pathogen Sclerotinia sclerotiorum, which causes yield losses in many plants, including oilseed rape (Brassica napus) cultivation. This research emphasizes the promising alternative of hybrid control, specifically using T. asperellum and C. minitans in strategy with synthetic fungicides. In vitro experiments demonstrated that T. asperellum effectively inhibited S. sclerotiorum mycelial growth, especially when combined with synthetic fungicides such as azoxystrobin. Field trials conducted over two years revealed that pre-sowing applications of T. asperellum and C. minitans, followed by fungicide treatments during the flowering stage, significantly reduced plant infection rates and improved both yield and seed quality across different oilseed rape cultivars. The results indicated an efficacy range of 81% to 100% in controlling the pathogen and highlighted the synergistic effects of combining biological and chemical controls. Overall, the research findings support the integration of T. asperellum and C. minitans into sustainable agricultural practices for oilseed rape, offering a viable strategy to enhance disease management while reducing reliance on chemical fungicides. This research underscores the importance of adopting innovative biocontrol approaches to improve crop health and productivity.

The increasing demand for sustainable agricultural practices has led researchers to explore alternative methods for controlling plant diseases and pests. Among these alternatives, essential oils (EOs) derived from various plant species have gained significant attention due to their broad-spectrum antimicrobial properties, which can be utilized in plant protection. Essential oils are volatile compounds that possess strong aromatic characteristics and are found in many medicinal and aromatic plants. They are known for their antifungal, antibacterial, and insecticidal activities, making them viable candidates for eco-friendly pest and disease management strategies. In this research, six essential oils—pine, patchouli, geranium, spruce, coriander, and eucalyptus oil—have been tested in vitro for controlling mycelium growth of Sclerotinia sclerotiorum, Botrytis cinerea, Alternaria brassicicola, and Cylindrosporium concentricum. The study also covers experiments in controlling pollen beetle and cabbage seed weevil (laboratory trials). In greenhouse conditions, the phytotoxicity of EOs to oilseed rape (Brassica napus L.) and the effect of these substances on the control of cornflower (Centaurea cyanus) were also tested. The results obtained indicate a large diversity of different essential oils in terms of their action on pathogens, pests, weeds, and winter rapeseed. Differences in their effectiveness were also found, depending on the applied dose.

The effect of azoxystrobin, prothioconazole, copper hydroxide, copper oxychloride and copper heptagluconate at different doses on inhibiting the growth of mycelia of pathogenic fungi Sclerotinia sclerotiorum, Botrytis cinerea, Rhizoctonia cerealis was studied. All active substances were tested in vitro on PDA (potato-glucose-agar) medium. The conducted assessments and measurements showed a high level of inhibition of mycelia growth of Sclerotinia sclerotiorum, Botrytis cinerea and Rhizoctonia cerealis in combinations in which modern forms of copper were used, with an effectiveness similar to the active substances of fungicides currently used in agriculture.

Diseases in crops are a major contributor to yield reduction and economic losses. Cercospora leaf spot (CLS), caused by Cercospora beticola, is among the most severe diseases affecting sugar beet and other crops. The increasing resistance of C. beticola to conventional chemical fungicides, along with their excessive application, exacerbates environmental pollution. This study investigates the antagonistic activity of a newly isolated strain, Bacillus velezensis KT27, against Cercospora beticola, Rhizoctonia cerealis, and Fusarium oxysporum under laboratory conditions. The bacterium's ability to produce lipopeptides (surfactin, iturin, and fengycin) and solubilize phosphorus, potassium, and zinc was also assessed. In vitro assays revealed that B. velezensis KT27 effectively inhibited C. beticola growth (60.2%), though it exhibited lower antagonistic activity against R. cerealis (22.5%) and F. oxysporum (15.5%). The elimination of bacterial biomass by centrifugation and the use of sterile supernatant reduced antifungal activity by more than 3.5-fold for all tested fungi, highlighting the importance of direct bacterial interactions. Notably, the antagonistic effect of B. velezensis KT27 against C. beticola significantly increased when bacterial cultures were supplemented with thermally inactivated fungal biomass of C. beticola especially R. cerealis. Field experiments demonstrated the high efficacy of B. velezensis KT27 biological control agent, particularly when induced by R. cerealis. The level of CLS protection achieved with the bacterial treatment was only 9.1% lower than that obtained using a combination of three chemical fungicides. Additionally, the biocontrol agent positively influenced sugar beet growth, leading to a root yield increase of up to 15.2% compared to the untreated control. These findings highlight the potential of B. velezensis KT27 as an effective and environmentally sustainable biocontrol agent against CLS in sugar beet cultivation.

Copper is a substance that has been used in plant protection for years. Currently, however, more and more attention is being paid to the need to limit the amount of it that ends up in the natural environment. At the same time, it is necessary to partially replace synthetic fungicides with alternative preparations. It is therefore worth looking for forms of copper that will contain a smaller amount of the mentioned ingredient while being highly effective. This experiment assessed the effect of selected preparations on the development of mycelium of pathogens of the Fusarium genus and the germination parameters of winter wheat. The efficacy of copper lignosulfonate and copper heptagluconate in seed treatment was tested, comparing them to copper oxychloride, copper hydroxide, and tebuconazole. The obtained results indicate that the use of copper lignosulfonate and copper heptagluconate allows for the effective limitation of the development of the tested pathogens (mycelium development was inhibited by up to 100%). Most of the preparations had no effect on the energy and germination capacity of winter wheat (only in one combination were the values lower than 90%). The use of preparations containing reduced doses of copper is an effective solution when applied as seed dressings.

Due to their multi-purpose use and, in many cases, lower requirements and financial outlays for cultivation, oats are an interesting crop. However, fungal diseases may contribute to significant declines in grain yields and quality. The aspects that may potentially influence this matter of fact include weather conditions. The aim of the study was to determine the severity of diseases caused by fungi in oat cultivation during the vegetation season. The next goal was to assess the efficacy of the selected active ingredients (a.i.) of fungicides from the chemical groups of triazoles and strobilurins in selected diseases’ control under various meteorological conditions. All of the fungicides were applied in the form of a spray treatment to reduce the severity of the diseases in the cultivation of different oat varieties. Husked and naked oat varieties were used. The health status of the oat plants was determined on the basis of a macroscopic evaluation of plants performed in accordance with the proper methodology. Field experiments were carried out under different weather conditions, which varied over the years during which the trials were conducted. Statistically significant differences were found in the reduction in infection for F and F1 leaves with D. avenae and P. coronata in comparison to the control treatment, regardless of the a.i. used. The use of a.i. tebuconazole (250 g/L), a.i. epoxiconazole (125 g/L), a.i. azoxystrobin (250 g/L) and a.i. picoxystrobin (250 g/L) enabled a reduction in the severity of oat helmintosporiosis in all years of the study for all the varieties analyzed. The efficacy was 72.4%, 74.2%, 71.5%, and 73.1%, respectively. Higher efficacy in reducing P. coronata was found in comparison with D. avenae. The obtained research results confirm the satisfactory efficacy of the above-mentioned active substances in reducing the fungi D. avenae and P. coronata.

Currently, researchers are looking for ways to replace synthetic pesticides with substances of natural origin. Essential oils are produced by plants, among other things, to protect against pathogens, which is why there is interest in their use as fungicides. This experiment assessed the composition of essential oils from a commercial source, their impact on the development of mycelium of pathogens of the Fusarium genus, and the possibility of using them as a pre-sowing treatment. Grains of winter wheat (Triticum aestivum L.) and corn (Zea mays L.) were inoculated with a suspension of mycelium and spores of fungi of the Fusarium genus and then soaked in solutions containing oils of sage (Salvia officinalis L.), cypress (Cupressus sempervirens L.), cumin (Cuminum cyminum L.), and thyme (Thymus vulgaris L.). The obtained results indicate that thyme essential oil had the strongest effect on limiting the development of Fusarium pathogens and seedling infection, but at the same time it had an adverse effect on the level of germination and seedling development of the tested plants. The remaining essential oils influenced the mentioned parameters to varying degrees. Selected essential oils can be an alternative to synthetic fungicides, but they must be selected appropriately.

Poland, like other countries in the world, increasingly experiences the ongoing climate change that is a critical yield-limiting factor. The use of biostimulants in agriculture has shown tremendous potential in combating climate change-induced stresses such as drought, temperature stress, etc. They could be a promising tool in the current crop production scenario. Biostimulants are organic compounds, microbes, or amalgamation of both that could regulate plant growth behavior through molecular alteration and physiological, biochemical, and anatomical modulations. They can promote plant growth under various environmental stresses because they have a positive effect, in particular, on plant growth and resistance. There are many products of this type available on the market, including those of natural origin, which are part of the Integrated Pest Management. The ecotoxicity of chemical plant protection products, the negative effects of their use, and the change in regulations make it recommended to use low-risk chemicals and non-chemical methods, that involve the least risk to health and the environment, and at the same time ensure effective and efficient protection of crops. Natural origin biocomponents obtained by the supercritical CO2 extraction of plant material or by fermentation process in bioreactors were tested. Common maize (Zea mays L.) was selected as a test plant for growth tests at climate chambers. Results showed that the only supernatant (fermentation broth) obtained with the Paenibacillus bacteria (S2) had a positive effect on the germination index (GI > 100%) of maize seeds, compared to the obtained plant seed extracts from the crop of the legume family (Fabaceae) (E3) and from the crop of the smartweed family (Polygonaceae) (E9) (GI < 100%). The extracts E3, S1 (supernatant obtained with the use of bacteria from the genus Enterobacter) and S2 used as a single product and in combination with UAN+S, under optimal conditions of the experiment, had a positive effect on the maize root weight compared to the untreated, while under drought stress, a decrease in the root weight was observed. Moreover, on the basis of the conducted research, differences in the mycelial growth of selected fungi were found. The applied biocomponent S2 of microbial origin extract (supernatant 2) showed a mycelial growth-limiting effect on all tested Fusarium fungi isolated from the corn cobs.

The effect of three fungicide treatment programmes and the level of spring nitrogen fertilisation on the seed yield of two types ofcultivars of Brassica napus L. sown at two different seeding rates was studied in a field experiment. The subject of the study was anopen-pollinated cultivar ‘Casoar’ and a restored hybrid cultivar ‘Visby’. Three plant protection programmes, two levels of spring nitrogenfertilisation (160 and 220 kg N⋅ha1), and two different seeding rates for each cultivar (‘Visby’—50 and 70 seeds⋅⋅m2; ‘Casoar’—60 and 80 seeds⋅m2) were included. The most intensive protection programme comprised three fungicide treatments: first in autumn at the six-leaves-unfolded stage—BBCH 16, second in spring at the stem elongation stage—BBCH 33, and third at the full flowering stage—BBCH 65. One of two less intensive programmes of plant protection included fungicide application in autumn at the sixleaves-unfolded stage—BBCH 16 and at the full flowering stage—BBCH 65, while the second included fungicide application in spring at the stem elongation stage—BBCH 33 and at the full flowering stage—BBCH 65. The effectiveness of the protection programmes and nitrogen fertilisation was influenced by the intensity of abiotic stress factors. The average yield from the plots protected against pathogens was significantly higher than that from the untreated plots. The increase of nitrogen fertilisation from 160 to 220 kg⋅ha1 also caused a significant increase of average seed yield. The yield of cultivar ‘Visby’ was higher and less dependent on the seeding rate compared to cultivar ‘Casoar’.Keywords: Winter oilseed rape; Cultivars; Disease control; Nitrogen fertilisation; Seeding rate; Sclerotinia sclerotiorum; Leptosphaeria spp.; Alternaria spp. Botrytis cinerea.

Clubroot, caused by Plasmodiophora brassicae infection, is a disease of growing importance in cruciferous crops, including oilseed rape (Brassica napus). The affected plants exhibit prominent galling of the roots that impairs their capacity for water and nutrient uptake, which leads to growth retardation, wilting, premature ripening, or death. Due to the scarcity of effective means of protection against the pathogen, breeding of resistant varieties remains a crucial component of disease control measures. The key aspect of the breeding process is the identification of genetic factors associated with variable response to the pathogen exposure. Although numerous clubroot resistance loci have been described in Brassica crops, continuous updates on the sources of resistance are necessary. Many of the resistance genes are pathotype-specific, moreover, resistance breakdowns have been reported. In this study, we characterize the clubroot resistance locus in the winter oilseed rape cultivar “Tosca.” In a series of greenhouse experiments, we evaluate the disease severity of P. brassicae-challenged “Tosca”-derived population of doubled haploids, which we genotype with Brassica 60 K array and a selection of SSR/SCAR markers. We then construct a genetic map and narrow down the resistance locus to the 0.4 cM fragment on the A03 chromosome, corresponding to the region previously described as Crr3. Using Oxford Nanopore long-read genome resequencing and RNA-seq we review the composition of the locus and describe a duplication of TIR-NBS-LRR gene. Further, we explore the transcriptomic differences of the local genes between the clubroot resistant and susceptible, inoculated and control DH lines. We conclude that the duplicated TNL gene is a promising candidate for the resistance factor. This study provides valuable resources for clubroot resistance breeding programs and lays a foundation for further functional studies on clubroot resistance.

The study presents the results of research on the influence of a mineral growth stimulant containing titanium (Ti) in the form available to plants, applied to reduce the effects of biotic stresses caused by agrophages, namely fungal pathogens and selected insect pests. The study was conducted in 2014 and 2015 on winter oilseed rape, winter wheat, and maize. The purpose of the study was to determine the influence of the Ti containing stimulant on the degree of damage caused by major pests occurring in the crops (cabbage seed weevil, cereal leaf beetle, and European corn borer), the degree of infestation with fungal diseases (gray mold, Alternaria disease, eyespot, foot rot, sooty mold, glume blotch, Fusarium head blight, Fusarium stalk rot, maize smut, and brown spot), and yield parameters. The study showed that the stimulant containing Ti successfully reduced the occurrence of pest damage to winter rapeseed and winter wheat plants and the occurrence of diseases in winter rapeseed, winter wheat, and maize crops. Thus, the application of the Ti stimulant resulted in an increased yield of the crops being tested. The main factor explaining this phenomenon is unknown, and it is probably the result of several factors. The study contains the discussion on this phenomenon.

The implementation of direct subsidies for legumes in recent years is one of the main factors causing growth of the area of, among others, lupine crops in Poland. Occurrence of diseases, including anthracnose, which is dangerous for lupine, reduces the quantity and quality of crops. There are only two active substances (thiophanate methyl and chlorothalonil) registered for spray application to control the symptoms of anthracnose during the vegetation season. In order to check the possibilities of reducing the severity of anthracnose symptoms and the growth of Colletotrichum spp. – the perpetrators of the disease, field and laboratory experiments were carried out. In studies with yellow and narrow-leaved lupine, the possibilities of using fungicides belonging to chemical groups other than previously registered fungicides were determined. Preparations containing such active substances as picoxystrobin and tebuconazole reduced the occurrence of anthracnose symptoms on yellow lupine in a year with very high disease pressure. Under in vitro conditions Colletotrichum spp. growth was limited the most by the active substances such as prochloraz, picoxystrobin and tebuconazole.

The aim of the study was to define the importance of breeding cultivars resistant to pathogenic organisms and the assessment of its availability in IPM (Integrated Pest Management) of OSR (oilseed rape). The cultivation of OSR resistant or tolerant varieties in addition to agrotechnics, the use of natural elements of the ecosystem and the rational application of PPP and other agrochemicals, is one of the basic elements of the IPM. The System of Post-Registration Variety Testing (PDO) implemented in Poland allows for constant monitoring of the most important threats as well as genetic resistance of varieties under field conditions, in a diverse agro-climatic environment. The precise selection of the variety is an important element of IPM of OSR. The progress in breeding resistance to both biotic and abiotic factors is brought primarily by hybrid varieties. In recent years, this mainly applies to such economically important pathogenic organisms as: Leptosphaeria spp. (blackleg), Turnip yellow virus (TuYV) and Plasmodiophora brassicae (clubroot). Celem pracy było zdefiniowanie znaczenia hodowli odmian odpornych na organizmy chorobotwórcze oraz praktyczna ocena ich dostępności w integrowanej ochronie rzepaku. Uprawa odmian rzepaku odpornych lub tolerancyjnych na organizmy szkodliwe, obok agrotechniki, wykorzystania naturalnych elementów ekosystemu i racjonalnego stosowania środków ochrony roślin jest jednym z podstawowych założeń integrowanej ochrony tego gatunku. System Porejestrowego Doświadczalnictwa Odmianowego (PDO) realizowany w naszym kraju pozwala na stały monitoring zagrożeń biotycznych i ich nasilenia oraz odporności genetycznej odmian w warunkach polowych, w zróżnicowanym środowisku agroklimatycznym. Precyzyjny dobór odmiany jest ważnym elementem integrowanej uprawy i ochrony rzepaku. Postęp w hodowli odpornościowej, zarówno na czynniki biotyczne, jak i abiotyczne, wnoszą przede wszystkim odmiany mieszańcowe. W ostatnich latach dotyczy to głównie takich ważnych gospodarczo organizmów chorobotwórczych, jak: Leptosphaeria maculans (sucha zgnilizna kapustnych), Turnip yellow virus, TuYV (wirus żółtaczki rzepy) i Plasmodiophora brassicae (kiła kapusty).

Plasmodiophora brassicae is a pathogen that causes clubroot – one of the most serious and economically most important diseases of the Brassica family. Development of P. brassicae is influenced by factors such as temperature, humidity and soil pH. The effect of these factors may vary due to the adaptability of P. brassicae and unequal degree of resistance of plants to infection. The aim of the study was to determine the effect of temperature, humidity and soil pH on P. brassicae infection of plants susceptible to infection and plants with increased resistance. The experiment included three pH ranges of the substrate, 3 humidity variants and 4 temperature ranges. The study revealed that the development of P. brassicae was limited the most by the lowest temperature (13°C) and low humidity of the substrate, while high temperature and excess humidity showed the most stimulating effect on the pathogen. The optimum temperature for the development of the disease on sensitive varieties was 20–24°C, while on varieties with increased resistance 16–20°C. Plasmodiophora brassicae to patogen powodujący kiłę kapusty – jedną z najgroźniejszych i najważniejszych ekonomicznie chorób roślin z rodziny kapustowatych. Na jego rozwój wpływają m.in. takie czynniki, jak: temperatura, wilgotność oraz pH gleby. Działanie wymienionych czynników może się zmieniać w związku ze zdolnościami adaptacyjnymi P. brassicae oraz niejednakowym stopniem odporności uprawianych odmian. Celem pracy było określenie wpływu temperatury, wilgotności oraz pH podłoża na porażenie przez P. brassicae roślin wrażliwych na infekcję oraz roślin o podwyższonej odporności. W doświadczeniach uwzględniono trzy zakresy pH podłoża, 3 warianty wilgotności oraz 4 zakresy temperatur. Doświadczenia wykazały, że rozwój P. brassicae najbardziej ograniczała najniższa temperatura (13°C) oraz niska wilgotność podłoża, natomiast najbardziej stymulująco na patogena wpływała wysoka temperatura oraz wysoka wilgotność. Optymalna dla rozwoju choroby na odmianach wrażliwych była temperatura 20–24°C, natomiast na odmianach o podwyższonej odporności 16–20°C.