Carrot is one of the most frequently grown vegetables in Poland and in the world. Seed-borne pathogenic fungi negatively influence their quality as well as the quantity and quality of carrot root yield. Melatonin is a PGR, which includes protective effects against biotic and abiotic stress factors and antioxidant effects. The aim of this experiment was to determine the effect of osmopriming with melatonin on germination, vigor and carrot seeds health. Carrot seeds were osmoprimed in a solution of polyethylene glycol (PEG) with an osmotic potential of −1.5 MPa at 20 °C for 7 days; melatonin was added to the PEG solution at doses of 25, 50, 100 or 200 µM. Generally, osmopriming with the addition of melatonin significantly improved germination capacity at first and final counts (sample I about 7–14% and sample II 35–43%), reduced the incidence of Alternaria alternata, A. radicina and Fusarium spp. and increased the percentage of non-sporulating hyphae. Treating accelerated the germination of seeds at a significant rate in comparison with untreated seeds and treated with fungicide, especially at low dosage, i.e., 25–50 µM. MGT of primed seeds with the addition of melatonin at dose 25 µM shortened about 0.5 day (sample I) and 1 day (sample II) The effect of melatonin on seed quality parameters was comparable or better than treating with fungicide. The results suggest that melatonin could replace fungicides in the future, which are harmful to the environment.

Summary: Introduction: : Milk thistle (Silybum marianum (L.) Gaertn.) is an important medicinal plant. Achenes of milk thistle contain sylimarin, protecting liver cells against toxic compounds. Objective: The aim of the research was to find an optimum method of evaluation of milk thistle seed germination. Methods: Ten seed samples were tested. The seeds were germinated: on top of blotter paper, on top of blotter paper after seed disinfection, between pleated blotter paper, in rolled blotter paper and in sand. Germination at the first and final counts, the percentages of abnormal seedlings and dead seeds were determined. The correlation coefficients between seed germination, evaluated with various methods, and seedling emergence were calculated. Moreover, fungi associated with seeds and diseased seedlings were identified. Results: The lowest percentage of normal seedlings was observed after germination on the top of blotter. Highly significant positive correlations were noted between seedling emergence and seed germination at the final count evaluated in rolled paper, between pleated paper and in sand. The fungi from genera: Alternaria, Fusarium, Penicillium, Trichoderma, Ulocladium and Verticillium were frequently identified on seeds and seedlings. Conclusions: Infestation with fungi significantly affected milk thistle seed germination and plant emergence. Germination in rolled blotter paper may be recommended for evaluation of milk thistle seed germination, as the most practical and significantly correlated with seedling emergence.

Alternaria dauci (J.G. Kühn) J.W. Groves et Skolko and A. radicina Meier, Drechsler et E.D. Eddy are important seed-transmitted pathogens of carrot. The aim of this study was to evaluate the effects of acetic acid treatments on the quality of stored carrot seeds. Seeds of two samples were soaked for 30 min in 0.5, 1 and 2% acetic acid. Controls included untreated seeds, seeds soaked in distilled water and seeds treated with fungicide Zaprawa Nasienna T 75 WS/DS (a.i. thiram 75%). Germination, vigour and health of untreated and treated seeds were evaluated before and after 5 and 12 months of storage at 4 and 20 °C. Seeds of both samples treated with 0.5 and 1% acetic acid were characterized by higher germination capacity after storage than untreated seeds. However, treatments with 1 and 2% acetic acid negatively affected seed vigour. Generally, seeds of both samples treated with acetic acid were characterized by lower infestation with A. alternata and A. radicina after storage than untreated seeds and seeds soaked in distilled water. Moreover, acetic acid often controlled these fungi more effectively than the fungicide. Regardless of the storage duration, infestation with fungi was higher if seeds of both samples were stored at a lower temperature.

Botrytis allii and B. cinerea are important seed-transmitted pathogens of onion. The aim of this study was to determine the chemical compositions of fir, pine and thyme essential oils and evaluate their effects on the germination, vigour and health of onion seeds. Gas Chromatography/Mass Spectroscopy was used for the analysis of the oils’ chemical compositions. Seed germination, vigour and health tests were performed on untreated seeds and on seeds treated with volatile compounds of the oils applied at a concentration of 0.2 µL cm⁻³ for 6, 12, 24, 48 and 72 h or at a concentration of 0.4 µL cm⁻³ for 3, 6 and 12 h. The main components of fir oil were bornyl acetate (55.5%) and α-pinene (15.6%), pine oil contained mostly α-pinene (35.5%) and β-pinene (18.6%), and thymol (34.2%) and p-cymene (26.2%) prevailed in thyme oil. Almost all treatments significantly reduced seed infestation with Alternaria alternata and Fusarium spp., and some effectively controlled Botrytis spp., however, seed health improvement was usually associated with deterioration of seed germination and vigour. Only treatment with fir oil at a concentration of 0.2 µL cm⁻³ for 6 h effectively controlled seed-borne pathogens and positively affected seed germination. Considering the beneficial effect of the oils on seed health, further studies are necessary in order to establish the optimal conditions for onion seed treatment.

Onion seeds are often contaminated by pathogenic fungi, such as Botrytis spp., Fusarium spp., which decrease seed quality. The usage of hydrolates is an alternative method to chemical treatment, and is safe for the natural environment, human health and life. The aim of the experiment was the determination of the effect of treatment with oregano and coconut hydrolates on the quality of onion seeds. Germination, vigour and seed health of two samples of onion seeds were tested. Seed germination was evaluated according to ISTA Rules, seed health by agar test and vigour by seed speed and uniformity of germination. Seeds were treated with hydrolate solutions at concentrations of 10, 20, 50 and 100%; untreated seeds and seeds soaking in water and treated with fungicide were control. Generally, the use of hydrolates improved the germination capacity at first and final count for both analyzed samples. After treating with hydrolate solutions, less abnormal diseased seedlings were also observed. Higher concentrations of hydrolates were effective in the limitation of the incidence of fungi A. alternata, Cladosporium spp. and Fusarium spp., either by complete elimination or a reduction of their presence on the seeds.

The aim of the studies was to investigate the effect of camel grass, lavender, patchouli, peppermint and tea tree essential oils, and their mixtures on the in vitro growth of pathogenic fungi Cladobotryum dendroides and Mycogone perniciosa , occurring in the cultivation of button mushroom ( Agaricus bisporus ). The mycelial growth of the tested pathogens was evaluated on PDA medium. Essential oils were added in three doses: 0.25; 0.5 and 1 mg·cm ^–3 of PDA medium. Camel grass and peppermint essential oils applied at the highest dose inhibited completely the in vitro growth of C. dendroides mycelium. Lavender oil used at the amount of 1 mg·cm ^–3 reduced the growth of the pathogen by 90 %. In the case of M. perniciosa the complete inhibition of the pathogen’s growth was observed after the addition of camel grass oil to PDA medium, irrespective of a dose, and lavender oil at the doses of 0.5 and 1 mg·cm ^–3 . The efficacy of the tested mixtures against M. perniciosa was high. Generally, all mixtures of essential oils, irrespective of a dose, completely controlled the growth of the pathogen. The complete inhibition of the growth of C. dendroides was observed only on the medium with the addition of the mixture of camel grass and peppermint oils at the highest dose. The conducted research showed that natural essential oils due to their antifungal properties could be useful in the Integrated Disease Management for the protection of button mushroom against diseases. They could be an effective alternative to synthetic chemical fungicides.